Merge: combat engine N-body debt (§1–§6) + Pete's retreat bulletin

Casters could not cast in ordinary rooms — the auto-resolve engine has no action
picker, so a cleric on autopilot fought every room of every expedition with a
mace while its spellbook sat unused. It read as a balance problem (cleric 46%
vs fighter 81%) and was not one: cleric DIED less than mage, it just fled 167 of
500 runs, and one room loss ends the whole expedition.

§6 lets them cast, with a slot reserve so the trash rooms cannot eat the boss's
kit. Trailers came up, leaders did not move, and the class spread narrowed from
35pp to 26pp. Pete can now report the runs that simply fell apart, which he was
structurally incapable of doing before.

Claude-Session: https://claude.ai/code/session_01B2MwktU4RgfWkar8HM3zZn

cmd/expedition-sim/main.go

@@ -62,6 +62,7 @@ func main() {
 
 		party        = flag.Int("party", 1, "seat a party of N (1 = solo, the historical path). Followers are invited on Day 1 and buy their own supplies")
 		partyClasses = flag.String("party-classes", "", "comma-separated classes for the N-1 followers (default: clones of -class)")
+		companion    = flag.String("companion", "", "hire Pete into the party: \"auto\" fills the missing role, or name a class (cleric, fighter, …). Empty = no companion. He takes a seat but no loot/XP.")
 
 		jobs = flag.Int("jobs", 0, "matrix mode — concurrent worker count (each worker is a subprocess so it gets its own sqlite). 0 = runtime.NumCPU()")
 	)
@@ -88,7 +89,7 @@ func main() {
 				includeLog = *logFlag
 			}
 		})
-		runMatrix(*classes, *levels, *zones, *runs, *bank, *cap, *days, includeLog, *jobs, *trace, *petLevel, *party, *partyClasses)
+		runMatrix(*classes, *levels, *zones, *runs, *bank, *cap, *days, includeLog, *jobs, *trace, *petLevel, *party, *partyClasses, *companion)
 		return
 	}
 
@@ -103,7 +104,7 @@ func main() {
 		return
 	}
 
-	runSingle(*class, *level, *zone, *userTag, *dataDir, *bank, *cap, *days, *logFlag, followers)
+	runSingle(*class, *level, *zone, *userTag, *dataDir, *bank, *cap, *days, *logFlag, followers, *companion)
 }
 
 // runReal drives an existing character loaded from dataDir's gogobee.db through
@@ -161,7 +162,7 @@ func followerClasses(leaderClass string, party int, spec string) []string {
 	return out
 }
 
-func runSingle(class string, level int, zone, userTag, dataDir string, bank float64, cap, days int, includeLog bool, followers []string) {
+func runSingle(class string, level int, zone, userTag, dataDir string, bank float64, cap, days int, includeLog bool, followers []string, companion string) {
 	dir := dataDir
 	if dir == "" {
 		var err error
@@ -172,7 +173,7 @@ func runSingle(class string, level int, zone, userTag, dataDir string, bank floa
 		defer os.RemoveAll(dir)
 	}
 
-	res, err := runOne(dir, id.UserID(userTag), plugin.DnDClass(class), level, plugin.ZoneID(zone), bank, cap, days, followers)
+	res, err := runOne(dir, id.UserID(userTag), plugin.DnDClass(class), level, plugin.ZoneID(zone), bank, cap, days, followers, companion)
 	if err != nil {
 		if res != nil {
 			if !includeLog {
@@ -199,7 +200,7 @@ type matrixJob struct {
 	rep   int
 }
 
-func runMatrix(classes, levels, zones string, runs int, bank float64, cap, days int, includeLog bool, jobs int, trace bool, petLevel, party int, partyClasses string) {
+func runMatrix(classes, levels, zones string, runs int, bank float64, cap, days int, includeLog bool, jobs int, trace bool, petLevel, party int, partyClasses, companion string) {
 	cs := splitNonEmpty(classes)
 	ls := parseLevels(levels)
 	zs := splitNonEmpty(zones)
@@ -230,7 +231,7 @@ func runMatrix(classes, levels, zones string, runs int, bank float64, cap, days
 	var wg sync.WaitGroup
 	for i := 0; i < jobs; i++ {
 		wg.Add(1)
-		go matrixWorker(exe, workCh, resCh, &wg, bank, cap, days, includeLog, trace, petLevel, party, partyClasses)
+		go matrixWorker(exe, workCh, resCh, &wg, bank, cap, days, includeLog, trace, petLevel, party, partyClasses, companion)
 	}
 	go func() {
 		for _, j := range work {
@@ -249,7 +250,7 @@ func runMatrix(classes, levels, zones string, runs int, bank float64, cap, days
 	}
 }
 
-func matrixWorker(exe string, in <-chan matrixJob, out chan<- *plugin.SimResult, wg *sync.WaitGroup, bank float64, cap, days int, includeLog, trace bool, petLevel, party int, partyClasses string) {
+func matrixWorker(exe string, in <-chan matrixJob, out chan<- *plugin.SimResult, wg *sync.WaitGroup, bank float64, cap, days int, includeLog, trace bool, petLevel, party int, partyClasses, companion string) {
 	defer wg.Done()
 	for j := range in {
 		uid := fmt.Sprintf("@sim:%s-l%d-%s-%d", j.class, j.level, j.zone, j.rep)
@@ -275,6 +276,9 @@ func matrixWorker(exe string, in <-chan matrixJob, out chan<- *plugin.SimResult,
 		if partyClasses != "" {
 			args = append(args, "-party-classes", partyClasses)
 		}
+		if companion != "" {
+			args = append(args, "-companion", companion)
+		}
 		if trace {
 			args = append(args, "-trace")
 		}
@@ -314,7 +318,7 @@ func matrixWorker(exe string, in <-chan matrixJob, out chan<- *plugin.SimResult,
 	}
 }
 
-func runOne(dataDir string, uid id.UserID, class plugin.DnDClass, level int, zone plugin.ZoneID, bank float64, cap, days int, followers []string) (*plugin.SimResult, error) {
+func runOne(dataDir string, uid id.UserID, class plugin.DnDClass, level int, zone plugin.ZoneID, bank float64, cap, days int, followers []string, companion string) (*plugin.SimResult, error) {
 	runner, err := plugin.NewSimRunner(dataDir)
 	if err != nil {
 		return nil, fmt.Errorf("init runner: %w", err)
@@ -338,6 +342,7 @@ func runOne(dataDir string, uid id.UserID, class plugin.DnDClass, level int, zon
 		runner.Euro.Credit(muid, bank, "expedition-sim bankroll")
 		members = append(members, muid)
 	}
+	runner.Companion = companion
 	return runner.RunPartyExpedition(uid, members, zone, cap, days)
 }
 

internal/db/db.go

@@ -401,6 +401,41 @@ func runMigrations(d *sql.DB) error {
 		// there is no read-modify-write race and no second field to disagree.
 		// DEFAULT 0 == "no renown", correct for every pre-existing row, no bootstrap.
 		`ALTER TABLE player_meta ADD COLUMN renown_xp INTEGER NOT NULL DEFAULT 0`,
+
+		// The hireable companion (pete_adventure_news_plan.md, "Pete as a
+		// character"). Pete's roster seat records the class and level he was
+		// hired at, so a party that levels mid-expedition doesn't silently
+		// re-roll its hireling into a different class three rooms in. Both are
+		// empty/0 on every player row and are only ever read for the one seat
+		// where isCompanionSeat holds — a player's row never consults them.
+		`ALTER TABLE expedition_party ADD COLUMN companion_class TEXT NOT NULL DEFAULT ''`,
+		`ALTER TABLE expedition_party ADD COLUMN companion_level INTEGER NOT NULL DEFAULT 0`,
+
+		// The companion's spell-slot ledger, "used" per slot level, as a compact
+		// CSV of six ints (index 0 unused; cantrips cost nothing).
+		//
+		// It has to live on the *expedition*, next to the class and level it is a
+		// pool for. A human caster's slots are dnd_spell_slots rows that persist
+		// across every fight of the run and only come back at camp, so rationing a
+		// pool across a 30-room day IS the caster's game. The first cut of this
+		// parked the companion's ledger on his combat seat instead — and a seat is
+		// per-session, so he walked into every single fight with a full pool. The
+		// sim caught it: a level-penalized, gearless hireling out-cleared a human
+		// cleric of the leader's own level by 15pp.
+		`ALTER TABLE expedition_party ADD COLUMN companion_slots_used TEXT NOT NULL DEFAULT ''`,
+
+		// The companion's body, carried across the run. -1 means "unset" — he is
+		// at full, which is what a fresh hire is.
+		//
+		// He used to re-seat at full max HP for *every* fight, because he has no
+		// dnd_character row for his HP to persist onto and the close-out skipped
+		// him ("he arrives fresh next time"). That is an infinite body: a player
+		// bleeds across a 30-room run and only heals at camp, while the hireling
+		// soaked half the incoming damage and reset. Measured, it is most of why a
+		// gearless, level-penalized hireling out-cleared a human cleric of the
+		// leader's own level — his party fled 5 runs out of 640 where the human
+		// party fled 56.
+		`ALTER TABLE expedition_party ADD COLUMN companion_hp INTEGER NOT NULL DEFAULT -1`,
 	}
 	for _, stmt := range columnMigrations {
 		if _, err := d.Exec(stmt); err != nil {

internal/plugin/adventure_companion.go

@@ -0,0 +1,702 @@
+package plugin
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"gogobee/internal/db"
+	"gogobee/internal/peteclient"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// Pete, the realm's embedded correspondent — the hireable NPC companion.
+// (pete_adventure_news_plan.md, "Pete as a character", surface 2.)
+//
+// A leader short a body can hire Pete into an expedition party. He fills the
+// role the party is missing, fights on autopilot, and files a dispatch about it
+// afterwards.
+//
+// The load-bearing rule, and the reason this file exists rather than a
+// player_meta row for @pete: **Pete is not a player and must never become one.**
+// He has no player_meta, no dnd_character, no inventory, no euros, and no DM
+// room. Mint him a player_meta row and ensureDnDCharacterForCombat will happily
+// auto-build him a real character on his first swing, at which point he shows up
+// in the graveyard, the leaderboards, the news as a subject, and the daily event
+// rolls — all of which would be a bot reporting on itself.
+//
+// So his seat is synthesized: companionCombatant builds a Combatant in memory
+// from the same tuned layers a player's sheet goes through, and every seam that
+// assumes a seat is a person is guarded by isCompanionSeat. The guards live at
+// four chokepoints, which between them cover the whole blast radius:
+//
+//   - expeditionAudience  — he is never in the DM fan-out (and so never in the
+//     per-member pet-arrival rolls or the daily event rolls that ride it)
+//   - partySize           — he is not a mouth: he doesn't inflate the supply
+//     burn he never bought packs for, and an NPC-only roster doesn't lock the
+//     leader out of their next expedition
+//   - partyCombatantsForSession / the seat builders — synthesize, don't load
+//   - the close-out loops  — no XP, no loot, no death row, no achievements
+//
+// He does count toward the enemy-HP scalar, because he is a body in the fight
+// and the boss can feel him.
+
+// companionUserIDDefault is Pete's real Matrix account. He is an independent bot
+// (his own repo, his own voice); gogobee already ignores him as a sender via
+// IGNORED_BOTS, so seating him here can never round-trip into command handling.
+// PETE_USER_ID overrides for a differently-homed deployment.
+const companionUserIDDefault = "@pete:parodia.dev"
+
+// companionDisplayName is what the party sees on his seat. gogobee names him but
+// does NOT voice him: his hire banter and his dispatch are written by his own
+// bot from the fact emitted below (project_pete_bot_architecture).
+const companionDisplayName = "Pete"
+
+// Hire pricing. The plan files cost as an open tuning question; this is the
+// first answer, not the final one. It scales with both the level he shows up at
+// and the tier he's walking into, so hiring him for a T5 boss run is not the
+// same 300 coins as a T1 stroll. Supply packs are 50/90 coins for reference —
+// he is deliberately a real expense, not a rounding error.
+//
+// PROD WATCH: at endgame coin balances this is likely too cheap to be a sink.
+// Raise companionHireCoinsPerLevel before raising the base — the base is what a
+// low-level player short a friend has to find.
+const (
+	companionHireBaseCoins     = 300
+	companionHireCoinsPerLevel = 60
+)
+
+// companionLevelPenalty is what makes him help rather than carry. He arrives one
+// level below the party's average — a competent below-median member, per the
+// difficulty plan's standing rule: lift the trailing case, never nerf the
+// leaders and never touch monster scaling.
+const companionLevelPenalty = 1
+
+var (
+	ErrCompanionAlreadyHired = errors.New("pete is already with this party")
+	ErrCompanionOnAssignment = errors.New("pete is out on assignment")
+	ErrCompanionNotHired     = errors.New("pete is not with this party")
+)
+
+// companionUserID resolves Pete's Matrix id.
+func companionUserID() id.UserID {
+	if v := strings.TrimSpace(os.Getenv("PETE_USER_ID")); v != "" {
+		return id.UserID(v)
+	}
+	return id.UserID(companionUserIDDefault)
+}
+
+// isCompanionSeat reports whether a roster seat / combat seat is Pete rather
+// than a player. This is the predicate every guard in the codebase keys on.
+func isCompanionSeat(userID id.UserID) bool { return userID == companionUserID() }
+
+// isCompanionUser is the string-keyed form, for the many seams that carry a raw
+// user_id out of the database.
+func isCompanionUser(userID string) bool { return id.UserID(userID) == companionUserID() }
+
+// companionHireCost is what the leader pays to bring him along, in coins.
+func companionHireCost(level int, tier ZoneTier) int {
+	if level < 1 {
+		level = 1
+	}
+	t := int(tier)
+	if t < 1 {
+		t = 1
+	}
+	return (companionHireBaseCoins + companionHireCoinsPerLevel*level) * t
+}
+
+// ── who he shows up as ───────────────────────────────────────────────────────
+
+// companionRoleFill picks the class Pete plays. He is role-fluid — that is the
+// whole point of hiring him — so by default he fills the hole in the roster: no
+// healer, he's a Cleric; no damage, he's a Mage; nobody up front, he's a
+// Fighter. A leader who knows better can override.
+//
+// The order of the checks is the priority order: a party with neither a healer
+// nor a front line gets the healer, because a party that cannot heal is the one
+// that dies.
+func companionRoleFill(partyClasses []DnDClass) DnDClass {
+	var hasHealer, hasFront, hasDamage bool
+	for _, c := range partyClasses {
+		switch c {
+		case ClassCleric, ClassDruid, ClassBard:
+			hasHealer = true
+		case ClassPaladin:
+			// The one chassis that answers two questions at once.
+			hasHealer, hasFront = true, true
+		case ClassFighter:
+			hasFront = true
+		case ClassMage, ClassSorcerer, ClassWarlock, ClassRogue, ClassRanger:
+			hasDamage = true
+		}
+	}
+	switch {
+	case !hasHealer:
+		return ClassCleric
+	case !hasFront:
+		return ClassFighter
+	case !hasDamage:
+		return ClassMage
+	default:
+		// A complete party that hires him anyway gets a second pair of hands up
+		// front — the least redundant thing he can be.
+		return ClassFighter
+	}
+}
+
+// parseCompanionClass resolves an explicit `!expedition hire cleric` override.
+// Empty (or unknown) means auto-fill.
+func parseCompanionClass(arg string) (DnDClass, bool) {
+	arg = strings.ToLower(strings.TrimSpace(arg))
+	if arg == "" || arg == "auto" {
+		return "", false
+	}
+	for _, ci := range dndClasses {
+		if !ci.Playable {
+			continue
+		}
+		if string(ci.Key) == arg || strings.EqualFold(ci.Display, arg) {
+			return ci.Key, true
+		}
+	}
+	return "", false
+}
+
+// companionHumans is every *player* on the expedition — the roster if one exists,
+// and otherwise the owner alone.
+//
+// The fallback is the whole point. A solo expedition has NO expedition_party rows
+// (see partyMembers: absence means solo, and the roster only materializes on the
+// first successful invite). Reading the roster alone therefore answers "nobody" for
+// exactly the player this feature exists for: the one with no friends around, who
+// is hiring Pete *because* they are alone.
+//
+// Getting this wrong is not a small error. It hired every solo player a **level-1**
+// Pete — in a tier-4 zone, against a boss that had just gained 15% HP and a full
+// extra set of actions to account for him. He died on contact and left the leader
+// fighting an inflated boss alone. A 1500-run sweep measured it: solo 65% clear,
+// two humans 87%, solo+Pete 33%. The companion was worse than no companion, and
+// this line is why.
+func companionHumans(expeditionID string) []*DnDCharacter {
+	var owner string
+	if err := db.Get().QueryRow(
+		`SELECT user_id FROM dnd_expedition WHERE expedition_id = ?`,
+		expeditionID).Scan(&owner); err != nil {
+		return nil
+	}
+	seats, err := partyHumans(expeditionID, owner)
+	if err != nil {
+		return nil
+	}
+	out := make([]*DnDCharacter, 0, len(seats))
+	for _, s := range seats {
+		if dc, _ := LoadDnDCharacter(s.UserID); dc != nil {
+			out = append(out, dc)
+		}
+	}
+	return out
+}
+
+// companionPartyLevel is the level he arrives at: the party's average, less
+// companionLevelPenalty, floored at 1.
+func companionPartyLevel(expeditionID string) int {
+	chars := companionHumans(expeditionID)
+	if len(chars) == 0 {
+		return 1
+	}
+	sum := 0
+	for _, dc := range chars {
+		sum += dc.Level
+	}
+	lvl := sum/len(chars) - companionLevelPenalty
+	if lvl < 1 {
+		lvl = 1
+	}
+	return lvl
+}
+
+// companionPartyClasses reads the classes already on the expedition, for the role
+// fill. Solo resolves to the owner's class, so a lone fighter gets a healer rather
+// than the empty-party default.
+func companionPartyClasses(expeditionID string) []DnDClass {
+	chars := companionHumans(expeditionID)
+	out := make([]DnDClass, 0, len(chars))
+	for _, dc := range chars {
+		out = append(out, dc.Class)
+	}
+	return out
+}
+
+// ── his sheet, which lives only in memory ────────────────────────────────────
+
+// companionSheet synthesizes the DnDCharacter Pete fights as. It is built, used,
+// and thrown away inside a single combat build — it is never saved, and
+// SaveDnDCharacter must never be called on it.
+//
+// Stats come from the same class-priority + race-mod pipeline autoBuildCharacter
+// uses for a real character, so he is statted like a player of his level rather
+// than by a bespoke NPC table that would drift away from the tuned math. Human
+// is deliberate: the +1-to-all is the most neutral race in the book, so his
+// class is doing the work rather than a race pick nobody chose.
+func companionSheet(class DnDClass, level int) *DnDCharacter {
+	if level < 1 {
+		level = 1
+	}
+	scores := applyRaceMods(RaceHuman, classStatPriority(class))
+	c := &DnDCharacter{
+		UserID: companionUserID(),
+		Race:   RaceHuman,
+		Class:  class,
+		Level:  level,
+		STR:    scores[0], DEX: scores[1], CON: scores[2],
+		INT: scores[3], WIS: scores[4], CHA: scores[5],
+		CreatedAt: time.Now().UTC(),
+		UpdatedAt: time.Now().UTC(),
+	}
+	c.HPMax = computeMaxHP(c.Class, abilityModifier(c.CON), c.Level)
+	c.HPCurrent = c.HPMax
+	return c
+}
+
+// companionAdvCharacter is the AdventureCharacter half of the synthetic sheet:
+// the shim DerivePlayerStats needs. CombatLevel round-trips back to the D&D
+// level through dndLevelFromCombatLevel (level*5), so the two halves agree.
+func companionAdvCharacter(level int) *AdventureCharacter {
+	return &AdventureCharacter{
+		UserID:      companionUserID(),
+		DisplayName: companionDisplayName,
+		CombatLevel: level * 5,
+		Alive:       true,
+	}
+}
+
+// companionGearTier maps his level onto the equipment tier a player of that
+// level would plausibly be carrying: 1–4 → T1, 5–8 → T2, and so on to T5.
+func companionGearTier(level int) int {
+	t := (level + 3) / 4
+	if t < 1 {
+		t = 1
+	}
+	if t > 5 {
+		t = 5
+	}
+	return t
+}
+
+// companionGear is the kit he walks in with — a working reporter's kit, bought
+// with expenses and kept in serviceable shape.
+//
+// He has to have one. The gear layer is not decoration: unarmored, stats.AC is
+// never set at all (computeArmorAC only fires when armor exists) and he walks in
+// at AC 3, hit by everything; weaponless, stats.Weapon stays nil and he swings
+// for a flat 5 at every level, which by L14 is nothing. "No gear" is not a
+// below-median player, it is a broken one.
+//
+// The below-median comes from everywhere else: he is a level down, his gear is
+// never Masterwork, and he carries no magic items, no subclass and no armed
+// ability. The weapon names are chosen to hit the right branch of
+// synthesizeWeaponProfile for the class — it best-fits off the name.
+func companionGear(class DnDClass, level int) map[EquipmentSlot]*AdvEquipment {
+	tier := companionGearTier(level)
+
+	weapon := "Service Mace"
+	switch class {
+	case ClassFighter, ClassPaladin:
+		weapon = "Service Sword"
+	case ClassRogue:
+		weapon = "Service Dagger"
+	case ClassRanger:
+		weapon = "Service Bow"
+	case ClassMage, ClassSorcerer, ClassWarlock, ClassDruid, ClassBard:
+		weapon = "Service Staff"
+	}
+
+	return map[EquipmentSlot]*AdvEquipment{
+		SlotWeapon: {Slot: SlotWeapon, Tier: tier, Condition: 100, Name: weapon},
+		SlotArmor:  {Slot: SlotArmor, Tier: tier, Condition: 100, Name: "Service Kit"},
+	}
+}
+
+// companionCombatant builds Pete's seat for a fight, mirroring buildZoneCombatants
+// but sourcing the sheet from memory instead of the database. He carries no
+// equipment, no treasure bonuses, no magic items, no chat level and no streak —
+// the three layers a player accumulates and he never will. That absence *is* the
+// below-median: he is a bare class chassis at a level below yours, and the gap
+// between him and a geared player of the same level is exactly the gear.
+func (p *AdventurePlugin) companionCombatant(
+	class DnDClass, level int, monster DnDMonsterTemplate, tier int, dmMood int,
+) (Combatant, Combatant, *DnDCharacter) {
+	tilt := dmMoodCombatTilt(dmMood)
+	char := companionAdvCharacter(level)
+	dc := companionSheet(class, level)
+
+	// The layer order is buildZoneCombatants', deliberately — a companion statted
+	// by a different pipeline would drift away from the tuned math the moment
+	// anyone touched one and not the other.
+	//
+	// What he does NOT get is the subclass layer, magic items, and an armed
+	// ability: three of the things a player accumulates and a hireling never will.
+	// Those absences, plus the level penalty and gear that is never Masterwork,
+	// are the "below median" — see companionGear for why the gear itself is not
+	// one of the things we take away.
+	gear := companionGear(class, level)
+	stats, mods := DerivePlayerStats(char, gear, &AdvBonusSummary{}, 0, 0, false)
+	applyDnDPlayerLayer(&stats, dc)
+	applyDnDEquipmentLayer(&stats, dc, gear)
+	applyDnDHPScaling(&stats, dc)
+	applyClassPassives(&stats, &mods, dc)
+	applyRacePassives(&stats, &mods, dc)
+
+	enemyStats, enemyMods := monster.toCombatStats()
+	if tier > 1 {
+		if floorAC := dndDungeonACBase + tier; enemyStats.AC < floorAC {
+			enemyStats.AC = floorAC
+		}
+		if floorAB := dndDungeonAtkBase + tier; enemyStats.AttackBonus < floorAB {
+			enemyStats.AttackBonus = floorAB
+		}
+	}
+	enemyStats.Attack += tilt.EnemyAttackDelta
+	if enemyStats.Attack < 1 {
+		enemyStats.Attack = 1
+	}
+	mods.InitiativeBias += tilt.InitiativeBias
+
+	player := Combatant{
+		Name:     companionDisplayName,
+		Stats:    stats,
+		Mods:     mods,
+		IsPlayer: true,
+	}
+	enemy := Combatant{
+		Name:    monster.Name,
+		Stats:   enemyStats,
+		Mods:    enemyMods,
+		Ability: monster.Ability,
+	}
+	return player, enemy, dc
+}
+
+// companionRosterLine is how he reads on `!expedition party`. DisplayName would
+// come back empty for him — he has no player_meta row to hold a name — so the
+// roster names him here, along with what he is currently playing, because "Pete
+// (member)" tells the leader nothing about the hole they paid to fill.
+func companionRosterLine(expeditionID string) string {
+	class, level := companionLoadout(expeditionID)
+	ci, _ := classInfo(class)
+	return fmt.Sprintf("**%s** _(hired — level %d %s)_\n", companionDisplayName, level, ci.Display)
+}
+
+// ── the hire, persisted on the roster ────────────────────────────────────────
+
+// companionLoadout reads back the class and level he was hired at. It is stored
+// on the roster row rather than re-derived per fight, so a party that levels
+// mid-expedition doesn't quietly re-roll their hireling into a different class
+// three rooms in.
+func companionLoadout(expeditionID string) (DnDClass, int) {
+	var class string
+	var level int
+	err := db.Get().QueryRow(`
+		SELECT companion_class, companion_level
+		  FROM expedition_party
+		 WHERE expedition_id = ? AND user_id = ?`,
+		expeditionID, string(companionUserID())).Scan(&class, &level)
+	if err != nil || class == "" {
+		return ClassFighter, 1
+	}
+	return DnDClass(class), level
+}
+
+// ── his spell slots, which live on the expedition ────────────────────────────
+//
+// A human caster's slots are dnd_spell_slots rows: one pool, spent across every
+// fight of the run, refilled only at camp. Rationing it is the caster's game. The
+// companion has no rows, so his pool lives on his roster row — the same row his
+// class and level live on, and with the same lifetime.
+//
+// It must NOT live on his combat seat. A seat is per-session and every fight opens
+// a new one, so a seat-scoped pool refills itself between fights: an infinite
+// caster. That is not a theory — the first cut did exactly that, and the sim
+// measured a gearless, level-penalized hireling out-clearing a human cleric of the
+// leader's own level by 15pp.
+
+// companionSlotsCSV encodes/decodes the ledger. CSV of six ints rather than JSON
+// because it is six ints.
+func companionSlotsDecode(s string) [6]int {
+	var out [6]int
+	for i, f := range strings.Split(s, ",") {
+		if i >= len(out) {
+			break
+		}
+		n, err := strconv.Atoi(strings.TrimSpace(f))
+		if err != nil || n < 0 {
+			continue
+		}
+		out[i] = n
+	}
+	return out
+}
+
+func companionSlotsEncode(used [6]int) string {
+	parts := make([]string, len(used))
+	for i, n := range used {
+		parts[i] = strconv.Itoa(n)
+	}
+	return strings.Join(parts, ",")
+}
+
+// companionSlotsForRun reads the ledger for the companion on the expedition that
+// owns runID. A run with no companion (or no expedition) reads as an empty pool,
+// which is the correct answer: nobody spent anything.
+func companionSlotsForRun(runID string) [6]int {
+	var raw string
+	err := db.Get().QueryRow(`
+		SELECT p.companion_slots_used
+		  FROM expedition_party p
+		  JOIN dnd_expedition e ON e.expedition_id = p.expedition_id
+		 WHERE e.run_id = ? AND p.user_id = ?`,
+		runID, string(companionUserID())).Scan(&raw)
+	if err != nil {
+		return [6]int{}
+	}
+	return companionSlotsDecode(raw)
+}
+
+// setCompanionSlotsForRun writes it back.
+func setCompanionSlotsForRun(runID string, used [6]int) error {
+	_, err := db.Get().Exec(`
+		UPDATE expedition_party
+		   SET companion_slots_used = ?
+		 WHERE user_id = ?
+		   AND expedition_id = (SELECT expedition_id FROM dnd_expedition WHERE run_id = ?)`,
+		companionSlotsEncode(used), string(companionUserID()), runID)
+	return err
+}
+
+// refreshCompanionSlots empties the ledger — his half of the camp rest that calls
+// refreshSpellSlots for every human. Keyed by expedition, because camp is.
+func refreshCompanionSlots(expeditionID string) error {
+	_, err := db.Get().Exec(`
+		UPDATE expedition_party SET companion_slots_used = ''
+		 WHERE expedition_id = ? AND user_id = ?`,
+		expeditionID, string(companionUserID()))
+	return err
+}
+
+// ── his body, which is also carried across the run ───────────────────────────
+//
+// companionUnsetHP is "no wound recorded" — a fresh hire, or a companion who has
+// just broken camp. Seating reads it as full.
+const companionUnsetHP = -1
+
+// companionHPFor reads the HP he carries into his next fight, or companionUnsetHP
+// when he is unhurt. A run with no companion reads unset, which is harmless: there
+// is nobody to seat.
+func companionHPFor(expeditionID string) int {
+	hp := companionUnsetHP
+	err := db.Get().QueryRow(`
+		SELECT companion_hp FROM expedition_party
+		 WHERE expedition_id = ? AND user_id = ?`,
+		expeditionID, string(companionUserID())).Scan(&hp)
+	if err != nil {
+		return companionUnsetHP
+	}
+	return hp
+}
+
+// companionSeatHP is what he actually sits down with: his carried wound, clamped
+// into [1, maxHP].
+//
+// The floor of 1 is deliberate. He can be dropped *inside* a fight — the engine
+// counts him out like any other seat — but he does not stay dead between them,
+// because there is no companion-death mechanic and inventing one here would be a
+// second feature smuggled into a bug fix. Coming back on 1 HP is a real penalty
+// (one hit and he is down again) without pretending to be a corpse rule.
+func companionSeatHP(expeditionID string, maxHP int) int {
+	hp := companionHPFor(expeditionID)
+	if hp == companionUnsetHP || hp > maxHP {
+		return maxHP
+	}
+	if hp < 1 {
+		return 1
+	}
+	return hp
+}
+
+// setCompanionHP records the HP he walked out of a fight with.
+func setCompanionHP(expeditionID string, hp int) error {
+	_, err := db.Get().Exec(`
+		UPDATE expedition_party SET companion_hp = ?
+		 WHERE expedition_id = ? AND user_id = ?`,
+		hp, expeditionID, string(companionUserID()))
+	return err
+}
+
+// setCompanionHPForRun is setCompanionHP for the turn-based close-out, which
+// holds a run id rather than an expedition id.
+func setCompanionHPForRun(runID string, hp int) error {
+	_, err := db.Get().Exec(`
+		UPDATE expedition_party
+		   SET companion_hp = ?
+		 WHERE user_id = ?
+		   AND expedition_id = (SELECT expedition_id FROM dnd_expedition WHERE run_id = ?)`,
+		hp, string(companionUserID()), runID)
+	return err
+}
+
+// refreshCompanionHP is his half of the camp heal: back to full, like every human
+// at a standard rest.
+func refreshCompanionHP(expeditionID string) error {
+	_, err := db.Get().Exec(`
+		UPDATE expedition_party SET companion_hp = ?
+		 WHERE expedition_id = ? AND user_id = ?`,
+		companionUnsetHP, expeditionID, string(companionUserID()))
+	return err
+}
+
+// companionLoadoutForRun is companionLoadout keyed by the zone run instead of
+// the expedition. A CombatSession carries a RunID, not an expedition id, and the
+// per-turn rebuild is the hottest caller — so the join lives here rather than
+// making every caller resolve the expedition first.
+//
+// A run with no expedition (a standalone !zone run, which can have no companion)
+// finds no row and falls back, which is the correct reading.
+func companionLoadoutForRun(runID string) (DnDClass, int) {
+	var class string
+	var level int
+	err := db.Get().QueryRow(`
+		SELECT p.companion_class, p.companion_level
+		  FROM expedition_party p
+		  JOIN dnd_expedition e ON e.expedition_id = p.expedition_id
+		 WHERE e.run_id = ? AND p.user_id = ?`,
+		runID, string(companionUserID())).Scan(&class, &level)
+	if err != nil || class == "" {
+		return ClassFighter, 1
+	}
+	return DnDClass(class), level
+}
+
+// companionExpeditionFor resolves the expedition a leader is running, for the
+// seat builder — which has the roster but not the expedition id. Empty string
+// when there is none, which companionLoadout reads as "no row" and falls back.
+func companionExpeditionFor(leader id.UserID) string {
+	e, _, err := activeExpeditionFor(leader)
+	if err != nil || e == nil {
+		return ""
+	}
+	return e.ID
+}
+
+// companionSeated reports whether Pete is on this roster.
+func companionSeated(expeditionID string) bool {
+	var one int
+	err := db.Get().QueryRow(`
+		SELECT 1 FROM expedition_party WHERE expedition_id = ? AND user_id = ?`,
+		expeditionID, string(companionUserID())).Scan(&one)
+	return err == nil
+}
+
+// hireCompanion seats Pete. The seat check, the availability check and the
+// insert share a transaction, so two leaders racing for him cannot both win.
+//
+// He is globally exclusive — one party at a time. That is not a limitation to
+// route around: "Pete is out on assignment" is the scarcity knob the plan asks
+// for, and it is also why he cannot be the answer to every run.
+func hireCompanion(expeditionID string, class DnDClass, level int) error {
+	tx, err := db.Get().Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	if err := seatLeader(tx, expeditionID); err != nil {
+		return err
+	}
+
+	// Is he already out with somebody? Scoped to live expeditions, so a roster
+	// row stranded by a crash cannot make him unhireable forever.
+	var busyOn string
+	err = tx.QueryRow(`
+		SELECT p.expedition_id
+		  FROM expedition_party p
+		  JOIN dnd_expedition e ON e.expedition_id = p.expedition_id
+		 WHERE p.user_id = ? AND e.status IN ('active', 'extracting')
+		 LIMIT 1`, string(companionUserID())).Scan(&busyOn)
+	switch {
+	case err == nil && busyOn == expeditionID:
+		return ErrCompanionAlreadyHired
+	case err == nil:
+		return ErrCompanionOnAssignment
+	case !errors.Is(err, sql.ErrNoRows):
+		return err
+	}
+
+	var n int
+	if err := tx.QueryRow(
+		`SELECT COUNT(*) FROM expedition_party WHERE expedition_id = ?`,
+		expeditionID).Scan(&n); err != nil {
+		return err
+	}
+	if n >= expeditionPartyMax {
+		return ErrPartyFull
+	}
+
+	if _, err := tx.Exec(`
+		INSERT INTO expedition_party (expedition_id, user_id, role, companion_class, companion_level)
+		VALUES (?, ?, 'member', ?, ?)`,
+		expeditionID, string(companionUserID()), string(class), level); err != nil {
+		return fmt.Errorf("seat companion: %w", err)
+	}
+	return tx.Commit()
+}
+
+// dismissCompanion sends him home. Unlike a player member he can be removed
+// mid-run — he is staff, not a guest — but the fee is not refunded: he already
+// walked in.
+func dismissCompanion(expeditionID string) error {
+	res, err := db.Get().Exec(`
+		DELETE FROM expedition_party
+		 WHERE expedition_id = ? AND user_id = ?`,
+		expeditionID, string(companionUserID()))
+	if err != nil {
+		return err
+	}
+	if n, _ := res.RowsAffected(); n == 0 {
+		return ErrCompanionNotHired
+	}
+	return nil
+}
+
+// ── the dispatch ─────────────────────────────────────────────────────────────
+
+// emitCompanionHireFact tells Pete's bot he has been hired. gogobee states the
+// fact; Pete writes the sentence. Bulletin, not priority: a hire is a diary
+// entry, not a bulletin-interrupting event.
+//
+// The subject is the *leader*, so the leader's news opt-out is honoured — Pete
+// reporting "filled in as cleric for <someone who asked not to be named>" would
+// be exactly the leak the opt-out exists to prevent. Pete himself is never a
+// subject: he has no opt-out row and needs none.
+func emitCompanionHireFact(leader id.UserID, class DnDClass, level int, zone ZoneDefinition) {
+	name := charName(leader)
+	if name == "" {
+		return
+	}
+	ci, _ := classInfo(class)
+	emitFact(peteclient.Fact{
+		GUID:       "companion_hire:" + eventToken(leader, "companion_hire") + ":" + fmt.Sprint(time.Now().UTC().Unix()),
+		EventType:  "companion_hire",
+		Tier:       "bulletin",
+		Subject:    name,
+		Zone:       zone.Display,
+		Level:      level,
+		ClassRace:  ci.Display,
+		OccurredAt: time.Now().UTC().Unix(),
+	}, leader, "")
+}

internal/plugin/adventure_companion_test.go

@@ -0,0 +1,309 @@
+package plugin
+
+import (
+	"errors"
+	"testing"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// The companion's whole contract is "he fights, and he is not a player". These
+// tests pin both halves — and specifically the seams where an NPC seat would
+// otherwise be silently treated as a person.
+
+func TestCompanion_HiredSeatIsNotAMouth(t *testing.T) {
+	setupEmptyTestDB(t)
+	owner := id.UserID("@leader:example.org")
+	seedExpedition(t, "exp-hire", owner, "active")
+	seatLeaderFixture(t, "exp-hire")
+
+	if err := hireCompanion("exp-hire", ClassCleric, 4); err != nil {
+		t.Fatalf("hireCompanion: %v", err)
+	}
+
+	// The roster holds two seats...
+	members, err := partyMembers("exp-hire")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(members) != 2 {
+		t.Fatalf("roster has %d seats, want 2 (leader + companion)", len(members))
+	}
+
+	// ...but only one of them eats. partySize feeds the daily supply burn and the
+	// "your party is still waiting on you" lock-out; counting the companion would
+	// bill the leader for rations he never bought, and strand him out of his next
+	// expedition behind a party of one bot.
+	n, err := partySize("exp-hire")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != 1 {
+		t.Errorf("partySize = %d, want 1 — the companion is not a mouth", n)
+	}
+}
+
+func TestCompanion_GetsNoMailButTakesASeat(t *testing.T) {
+	setupEmptyTestDB(t)
+	owner := id.UserID("@leader2:example.org")
+	seedExpedition(t, "exp-mail", owner, "active")
+	seatLeaderFixture(t, "exp-mail")
+	if err := hireCompanion("exp-mail", ClassFighter, 3); err != nil {
+		t.Fatalf("hireCompanion: %v", err)
+	}
+	exp, err := getExpedition("exp-mail")
+	if err != nil || exp == nil {
+		t.Fatalf("getExpedition: %v", err)
+	}
+
+	// Mail and seats are different sets. Every DM seam reads the audience; the
+	// combat roster reads the seats. Getting this backwards either DMs a bot or
+	// charges a leader for a body that never sits down.
+	for _, uid := range expeditionAudience(exp) {
+		if isCompanionSeat(uid) {
+			t.Fatal("companion is in the DM audience — he does not get mail")
+		}
+	}
+	var seated bool
+	for _, uid := range expeditionSeats(exp) {
+		if isCompanionSeat(uid) {
+			seated = true
+		}
+	}
+	if !seated {
+		t.Fatal("companion is not in the fight roster — he was paid for and never sat down")
+	}
+}
+
+func TestCompanion_IsGloballyExclusive(t *testing.T) {
+	setupEmptyTestDB(t)
+	for _, e := range []struct {
+		id    string
+		owner id.UserID
+	}{{"exp-a", "@a:example.org"}, {"exp-b", "@b:example.org"}} {
+		seedExpedition(t, e.id, e.owner, "active")
+		seatLeaderFixture(t, e.id)
+	}
+
+	if err := hireCompanion("exp-a", ClassMage, 5); err != nil {
+		t.Fatalf("first hire: %v", err)
+	}
+	// He is one person. A second party cannot have him — "out on assignment" is
+	// the scarcity knob, not a bug to route around.
+	if err := hireCompanion("exp-b", ClassMage, 5); !errors.Is(err, ErrCompanionOnAssignment) {
+		t.Errorf("second hire err = %v, want ErrCompanionOnAssignment", err)
+	}
+	// Re-hiring him into the party he's already with is its own answer.
+	if err := hireCompanion("exp-a", ClassMage, 5); !errors.Is(err, ErrCompanionAlreadyHired) {
+		t.Errorf("re-hire err = %v, want ErrCompanionAlreadyHired", err)
+	}
+
+	// Dismissed, he's available again.
+	if err := dismissCompanion("exp-a"); err != nil {
+		t.Fatalf("dismiss: %v", err)
+	}
+	if err := hireCompanion("exp-b", ClassMage, 5); err != nil {
+		t.Errorf("hire after dismiss: %v, want success", err)
+	}
+}
+
+// The bug that made the whole feature worse than useless: a SOLO expedition has
+// no expedition_party rows at all (the roster only materializes on the first
+// invite), so reading the roster to size the companion answered "nobody" for
+// exactly the player who is hiring him — the one with no friends around. Every
+// solo hire got a level-1 Pete, in whatever tier the leader was actually in.
+func TestCompanion_SoloLeaderSizesHimCorrectly(t *testing.T) {
+	setupEmptyTestDB(t)
+	owner := id.UserID("@lonely:example.org")
+	seedExpedition(t, "exp-solo-hire", owner, "active")
+
+	// A level-12 fighter, adventuring alone. No roster rows exist.
+	if err := SaveDnDCharacter(&DnDCharacter{
+		UserID: owner, Race: RaceHuman, Class: ClassFighter, Level: 12,
+		STR: 18, DEX: 14, CON: 16, INT: 10, WIS: 10, CHA: 10,
+		HPMax: 120, HPCurrent: 120, ArmorClass: 18,
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	if got := companionPartyLevel("exp-solo-hire"); got != 11 {
+		t.Errorf("companionPartyLevel = %d, want 11 (the lone leader's 12, less the below-median step). "+
+			"A level-1 companion in the leader's zone is worse than no companion at all.", got)
+	}
+	// And he fills the hole the lone fighter actually has, rather than defaulting
+	// as if the party were empty.
+	if got := companionRoleFill(companionPartyClasses("exp-solo-hire")); got != ClassCleric {
+		t.Errorf("role fill for a lone fighter = %v, want cleric", got)
+	}
+}
+
+// §4 — asking for "the party" must never answer "nobody".
+//
+// A solo expedition has no expedition_party rows (absence means solo; the roster
+// materializes on the first invite). Every consumer that read the roster table
+// directly therefore got an empty list for a solo player and fell back to
+// whatever looked reasonable locally. That is how the companion was hired at
+// level 1 for exactly the player the feature exists for.
+//
+// expeditionParty always includes the owner. If this test ever fails, that
+// guarantee is gone and the same class of bug is back.
+func TestParty_SoloExpeditionStillHasAParty(t *testing.T) {
+	setupEmptyTestDB(t)
+	owner := id.UserID("@alone:example.org")
+	seedExpedition(t, "exp-alone", owner, "active")
+
+	// No roster rows exist at all.
+	rows, err := partyMembers("exp-alone")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rows) != 0 {
+		t.Fatalf("solo expedition has %d roster rows; the premise of this test is gone", len(rows))
+	}
+
+	// And yet the party is not empty.
+	seats, err := expeditionParty("exp-alone", string(owner))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(seats) != 1 || seats[0].UserID != owner || seats[0].Kind != SeatLeader {
+		t.Fatalf("expeditionParty on a solo run = %+v, want exactly the owner as leader. "+
+			"An empty answer here is what hires a level-1 companion.", seats)
+	}
+	humans, err := partyHumans("exp-alone", string(owner))
+	if err != nil || len(humans) != 1 {
+		t.Fatalf("partyHumans on a solo run = %+v (err %v), want the owner", humans, err)
+	}
+}
+
+func TestCompanion_RoleFillTakesTheHole(t *testing.T) {
+	tests := []struct {
+		name  string
+		party []DnDClass
+		want  DnDClass
+	}{
+		{"no healer", []DnDClass{ClassFighter, ClassRogue}, ClassCleric},
+		{"no front line", []DnDClass{ClassCleric, ClassMage}, ClassFighter},
+		{"no damage", []DnDClass{ClassCleric, ClassFighter}, ClassMage},
+		// A paladin covers healer AND front line, so paladin+rogue has no hole at
+		// all — it falls through to the default, a second body up front.
+		{"a complete party gets the default", []DnDClass{ClassPaladin, ClassRogue}, ClassFighter},
+		{"a paladin still leaves the damage hole", []DnDClass{ClassPaladin}, ClassMage},
+		{"solo fighter needs the medic first", []DnDClass{ClassFighter}, ClassCleric},
+		{"empty party", nil, ClassCleric},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := companionRoleFill(tc.party); got != tc.want {
+				t.Errorf("companionRoleFill(%v) = %v, want %v", tc.party, got, tc.want)
+			}
+		})
+	}
+}
+
+// §3 — an engine-driven seat's latch is permanent, and no command can take it.
+//
+// This is the invariant that, when it did not exist, made the companion stand in
+// fights doing nothing. The expedition autopilot drives a party by dispatching
+// each seat's turn AS that seat; his own auto-played move therefore arrived at
+// beginCombatTurn looking exactly like a human returning to the keyboard, and the
+// "they typed, so they're here" branch cleared the latch that was moving him.
+// After round 1 he never acted again — while the boss he had inflated by 15% HP
+// killed the party. The sweep measured it at -27pp clear rate.
+//
+// Autopilot is provisional (a human is away; a keystroke ends it). EngineDriven is
+// not (there is nobody to come back). They must never collapse into one flag.
+func TestCompanion_EngineSeatKeepsTheWheel(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	uid := id.UserID("@lead:example.org")
+
+	monster := dndBestiary["goblin"]
+	c, _, _ := p.companionCombatant(ClassFighter, 8, monster, 2, 0)
+	enemy := Combatant{Name: "x", Stats: CombatStats{MaxHP: 500, AC: 12, Attack: 4, AttackBonus: 4}}
+
+	sess, err := p.startPartyCombatSession("run-e", "enc", "goblin", &enemy, []CombatSeatSetup{
+		{UserID: uid, HP: 200, HPMax: 200, Mods: c.Mods, C: &c},
+		{UserID: companionUserID(), HP: 120, HPMax: 120, Mods: c.Mods, C: &c, EngineDriven: true},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !sess.seatIsEngineDriven(1) {
+		t.Fatal("companion seat is not engine-driven")
+	}
+	if sess.seatIsEngineDriven(0) {
+		t.Fatal("the human's seat came out engine-driven")
+	}
+	// The engine drives it without waiting on anybody...
+	if !sess.seatIsAutopiloted(1) || !sess.seatNeedsNoHuman(1) {
+		t.Fatal("an engine seat must resolve without waiting for a human")
+	}
+	// ...and the human's seat still waits for its human.
+	if sess.seatIsAutopiloted(0) {
+		t.Fatal("the human's seat was latched onto autopilot at seating")
+	}
+
+	// The wheel cannot be taken back, because there is nobody to take it. This is
+	// the exact line that used to strand him: a "keystroke" from his own id.
+	sess.actorStatusesPtr(1).Autopilot = false
+	if !sess.seatIsAutopiloted(1) {
+		t.Fatal("clearing Autopilot stranded the engine seat — EngineDriven must keep it moving")
+	}
+}
+
+// The one that actually matters: he has to FIGHT. Every other guard in this
+// file is about keeping him out of things, and a companion synthesized down to
+// zeroed stats would pass all of them while standing in the fight doing nothing
+// — a hire that silently buys the leader an empty chair.
+func TestCompanion_ActuallySwings(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+
+	monster := dndBestiary["goblin"]
+	tank := monster
+	tank.HP = 5000 // outlast the phase clock, so a real swing has time to land
+
+	pete, _, _ := p.companionCombatant(ClassFighter, 6, tank, 2, 0)
+
+	if pete.Stats.MaxHP <= 0 || pete.Stats.Attack <= 0 || pete.Stats.AC <= 0 {
+		t.Fatalf("companion built with dead stats (%d HP / %d atk / %d AC) — he'd stand in the fight and do nothing",
+			pete.Stats.MaxHP, pete.Stats.Attack, pete.Stats.AC)
+	}
+
+	enemy := Combatant{Name: tank.Name, Stats: CombatStats{MaxHP: 5000, AC: 10, Attack: 1, AttackBonus: 1}}
+	res := simulatePartyWithRNG([]Combatant{pete}, enemy, dungeonCombatPhases, seededRNG(7))
+
+	var swings int
+	for _, e := range res.Events {
+		if e.Actor == "player" && e.Seat == 0 && e.Roll > 0 {
+			swings++
+		}
+	}
+	if swings == 0 {
+		t.Fatal("the companion never swung — he was hired, seated, and did nothing")
+	}
+}
+
+func TestCompanion_SheetIsBelowMedianAndNeverPersisted(t *testing.T) {
+	setupEmptyTestDB(t)
+
+	// He is statted like a player of his level, so he never drifts from the tuned
+	// math — but he arrives a level down, which is the whole "help, never a carry"
+	// rule expressed in one number.
+	dc := companionSheet(ClassFighter, 7)
+	if dc.Level != 7 || dc.HPMax <= 0 {
+		t.Fatalf("companionSheet = level %d / %d HP, want a real level-7 chassis", dc.Level, dc.HPMax)
+	}
+
+	// And he leaves no trace: a player_meta row is the thing that would turn him
+	// into a real character everywhere (graveyard, news, XP, leaderboards), so the
+	// synthesis must not have written one.
+	if c, _ := LoadDnDCharacter(companionUserID()); c != nil {
+		t.Fatal("companion has a persisted dnd_character row — he is a player now, which is the one thing he must never be")
+	}
+	if _, err := loadAdvCharacter(companionUserID()); err == nil {
+		t.Fatal("companion has a persisted player_meta row — ensureDnDCharacterForCombat will auto-build him a character on his first swing")
+	}
+}

internal/plugin/combat_ally_heal_test.go

@@ -0,0 +1,174 @@
+package plugin
+
+import (
+	"strings"
+	"testing"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// §1 — the cleric fix.
+//
+// Until this landed, EVERY heal in the combat engine was self-scoped:
+// MistyHealProc healed the actor, HealItem fired the actor's own trigger, and
+// turnActionEffect.PlayerHeal wrote to the acting seat. There was no action of any
+// kind that could touch another seat's HP. A party cleric — the class whose entire
+// identity is keeping other people upright — could not put one hit point on a
+// friend, and N3 shipped that way without a single test going red, because party
+// combat had no golden.
+//
+// These tests exist so that can never be true again.
+
+// startAllyHealFight seats a healer at 0 and a hurt friend at 1.
+func startAllyHealFight(t *testing.T, p *AdventurePlugin, hurtHP int) *CombatSession {
+	t.Helper()
+	healer := basePlayer()
+	friend := basePlayer()
+	enemy := Combatant{Name: "dummy", Stats: CombatStats{MaxHP: 800, AC: 10, Attack: 1, AttackBonus: 1}}
+
+	// Distinct ids per fight: one active session per player is enforced, so two
+	// fights sharing a healer would collide.
+	tag := strings.ReplaceAll(t.Name(), "/", "_")
+	sess, err := p.startPartyCombatSession("run-"+tag, "enc", "goblin", &enemy, []CombatSeatSetup{
+		{UserID: healerID(tag), HP: 100, HPMax: 100, Mods: healer.Mods, C: &healer},
+		{UserID: friendID(tag), HP: hurtHP, HPMax: 100, Mods: friend.Mods, C: &friend},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return sess
+}
+
+func healerID(tag string) id.UserID { return id.UserID("@healer-" + tag + ":example.org") }
+func friendID(tag string) id.UserID { return id.UserID("@friend-" + tag + ":example.org") }
+
+func TestAllyHeal_LandsOnTheFriendNotTheCaster(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	sess := startAllyHealFight(t, p, 20)
+
+	healer, friend := basePlayer(), basePlayer()
+	players := []*Combatant{&healer, &friend}
+	enemy := Combatant{Name: "dummy", Stats: CombatStats{MaxHP: 800, AC: 10, Attack: 1, AttackBonus: 1}}
+	ct := &combatTurn{sess: sess, players: players, enemy: &enemy, seat: 0, uid: healerID(strings.ReplaceAll(t.Name(), "/", "_"))}
+
+	casterBefore, friendBefore := sess.seatHP(0), sess.seatHP(1)
+
+	_, err := p.driveCombatRound(ct, PlayerAction{
+		Kind: ActionCast,
+		Effect: &turnActionEffect{
+			Label: "Cure Wounds", Action: "spell_cast",
+			AllyHeal: 30, AllySeat: 1,
+		},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got := sess.seatHP(1); got != friendBefore+30 {
+		t.Errorf("friend HP = %d, want %d — the heal did not reach them. "+
+			"This is the bug: a cleric who cannot heal anyone but themselves.",
+			got, friendBefore+30)
+	}
+	if got := sess.seatHP(0); got > casterBefore {
+		t.Errorf("caster HP = %d (was %d) — the heal landed on the caster instead of the target",
+			got, casterBefore)
+	}
+}
+
+// A heal cannot exceed the target's ceiling, and cannot raise the dead. Death is
+// terminal for the fight — the close-out marks them, the hospital takes them — and
+// a heal that resurrected a corpse would quietly rewrite the loss rules every
+// close-out path depends on.
+func TestAllyHeal_CapsAtMaxAndWillNotRaiseTheDead(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+
+	t.Run("caps at max", func(t *testing.T) {
+		sess := startAllyHealFight(t, p, 90)
+		healer, friend := basePlayer(), basePlayer()
+		ct := &combatTurn{sess: sess, players: []*Combatant{&healer, &friend},
+			enemy: &Combatant{Name: "d", Stats: CombatStats{MaxHP: 800, AC: 10, Attack: 1, AttackBonus: 1}},
+			seat:  0, uid: healerID(strings.ReplaceAll(t.Name(), "/", "_"))}
+
+		if _, err := p.driveCombatRound(ct, PlayerAction{Kind: ActionCast,
+			Effect: &turnActionEffect{Label: "Cure", Action: "spell_cast", AllyHeal: 500, AllySeat: 1},
+		}); err != nil {
+			t.Fatal(err)
+		}
+		if got, want := sess.seatHP(1), sess.seatHPMax(1); got > want {
+			t.Errorf("friend healed to %d over a max of %d", got, want)
+		}
+	})
+
+	t.Run("will not raise the dead", func(t *testing.T) {
+		sess := startAllyHealFight(t, p, 0) // seat 1 is already down
+		healer, friend := basePlayer(), basePlayer()
+		ct := &combatTurn{sess: sess, players: []*Combatant{&healer, &friend},
+			enemy: &Combatant{Name: "d", Stats: CombatStats{MaxHP: 800, AC: 10, Attack: 1, AttackBonus: 1}},
+			seat:  0, uid: healerID(strings.ReplaceAll(t.Name(), "/", "_"))}
+
+		if _, err := p.driveCombatRound(ct, PlayerAction{Kind: ActionCast,
+			Effect: &turnActionEffect{Label: "Cure", Action: "spell_cast", AllyHeal: 50, AllySeat: 1},
+		}); err != nil {
+			t.Fatal(err)
+		}
+		if got := sess.seatHP(1); got > 0 {
+			t.Errorf("a downed seat was healed to %d — healing keeps people up, it does not bring them back", got)
+		}
+	})
+}
+
+// The target parser resolves against the people in the fight, and leaves anything
+// it does not recognise on the string for the spell parser — so every existing
+// `!cast` form still means what it always meant.
+func TestSplitCastTarget(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	sess := startAllyHealFight(t, p, 50)
+	healer, friend := basePlayer(), basePlayer()
+	healer.Name, friend.Name = "Ayla", "Bram"
+	ct := &combatTurn{sess: sess, players: []*Combatant{&healer, &friend},
+		enemy: &Combatant{Name: "d"}, seat: 0, uid: healerID(strings.ReplaceAll(t.Name(), "/", "_"))}
+
+	tName := t.Name()
+	tests := []struct {
+		name      string
+		in        string
+		wantArgs  string
+		wantSeat  int
+		wantError bool
+	}{
+		{"no target", "cure wounds", "cure wounds", -1, false},
+		{"slot level is not a target", "fireball 3", "fireball 3", -1, false},
+		{"@mention by display name", "cure wounds @Bram", "cure wounds", 1, false},
+		// The flag !help has advertised all along, and that parseCombatCast used to
+		// accept and silently throw away ("reserved for SP3").
+		{"--target flag", "cure wounds --target @Bram", "cure wounds", 1, false},
+		{"--target mid-string", "cure wounds --target Bram", "cure wounds", 1, false},
+		{"--target with no name", "cure wounds --target", "", -1, true},
+		{"bare display name", "cure wounds Bram", "cure wounds", 1, false},
+		{"by localpart", "cure wounds @" + friendID(strings.ReplaceAll(tName, "/", "_")).Localpart(), "cure wounds", 1, false},
+		{"targeting yourself is just casting it", "cure wounds @Ayla", "cure wounds", -1, false},
+		{"@mention of a stranger is an error", "cure wounds @nobody", "", -1, true},
+		{"an unknown bare word is left for the spell parser", "mass cure wounds", "mass cure wounds", -1, false},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			args, seat, errMsg := splitCastTarget(ct, 0, tc.in)
+			if tc.wantError {
+				if errMsg == "" {
+					t.Fatalf("splitCastTarget(%q) gave no error; a mistyped @mention would silently waste the slot", tc.in)
+				}
+				return
+			}
+			if errMsg != "" {
+				t.Fatalf("splitCastTarget(%q) errored: %s", tc.in, errMsg)
+			}
+			if args != tc.wantArgs || seat != tc.wantSeat {
+				t.Errorf("splitCastTarget(%q) = (%q, %d), want (%q, %d)",
+					tc.in, args, seat, tc.wantArgs, tc.wantSeat)
+			}
+		})
+	}
+}

internal/plugin/combat_cmd.go

@@ -105,7 +105,7 @@ func (p *AdventurePlugin) handleFightCmd(ctx MessageContext) error {
 	// this is a no-op there); mirror it here so the entry banner and the opening
 	// round resolve against the same ceiling startPartyCombatSession persisted and
 	// the rebuilt rounds use.
-	enemyHP := scaledEnemyMaxHP(enemy.Stats.MaxHP, len(seats))
+	enemyHP := scaledEnemyMaxHP(enemy.Stats.MaxHP, seatSetupWeight(seats))
 
 	// Fight-start one-shot resources (Abjuration Arcane Ward, etc.) are seeded
 	// per seat onto the session and its participant rows, so they survive the
@@ -425,7 +425,11 @@ func (p *AdventurePlugin) finishCombatSession(userID id.UserID, sess *CombatSess
 // returns the spell plus the resolved slot level. errMsg is non-empty and
 // player-facing on any validation failure. It performs NO resource spend —
 // the caller debits the slot only once the round is about to resolve.
-func parseCombatCast(userID id.UserID, c *DnDCharacter, args string) (SpellDefinition, int, string) {
+//
+// It takes the seat, not just the user, because "do you know this spell" is a
+// question about a combatant and only *usually* a question about a database row:
+// the hired companion has no rows and answers it from his synthetic sheet.
+func parseCombatCast(sess *CombatSession, seat int, userID id.UserID, c *DnDCharacter, args string) (SpellDefinition, int, string) {
 	tokens := strings.Fields(args)
 	upcast := 0
 	var spellTokens []string
@@ -473,7 +477,7 @@ func parseCombatCast(userID id.UserID, c *DnDCharacter, args string) (SpellDefin
 			return SpellDefinition{}, 0, fmt.Sprintf("At level %d, your Arcane Trickster magic only reaches level-%d spells.", c.Level, mx)
 		}
 	}
-	known, prepared, err := playerKnowsSpell(userID, spell.ID)
+	known, prepared, err := seatKnowsSpell(sess, seat, userID, spell.ID)
 	if err != nil {
 		return SpellDefinition{}, 0, "Couldn't check your spell list."
 	}
@@ -526,12 +530,92 @@ func (p *AdventurePlugin) handleCombatCastCmd(ctx MessageContext, args string) e
 // the roster so the buff is live for the round's enemy turn. Before P5 that
 // delta went to the session's embedded copy — seat 0 — so a party member
 // buffing themselves would have buffed the leader.
+// splitCastTarget peels an optional ally target off the end of a `!cast` argument
+// — `cure wounds @alex`, or just `cure wounds alex` — and resolves it to a seat.
+//
+// It resolves against the people *in this fight* rather than the room, which is
+// both cheaper (no ResolveUser round-trip, no RoomID to thread down here) and
+// more correct: the only legal target of a combat heal is somebody sitting in the
+// combat. Anything it does not recognise is left on the string for the spell
+// parser, so `!cast cure wounds` and `!cast fireball 3` behave exactly as before.
+//
+// Both spellings work: the `--target @alex` flag that `!help` has advertised all
+// along (and that parseCombatCast has been silently swallowing since SP2 —
+// "reserved for SP3, accept and ignore"), and a plain trailing `@alex`.
+//
+// Returns (remainingArgs, seat, errMsg). seat is -1 when no target was named.
+func splitCastTarget(ct *combatTurn, caster int, args string) (string, int, string) {
+	args = strings.TrimSpace(args)
+	if args == "" || !ct.isParty() {
+		return args, -1, ""
+	}
+	fields := strings.Fields(args)
+
+	// `--target <who>` anywhere in the string.
+	explicit, name := false, ""
+	for i := 0; i < len(fields); i++ {
+		if !strings.EqualFold(fields[i], "--target") {
+			continue
+		}
+		if i+1 >= len(fields) {
+			return args, -1, "`--target` needs a name: `!cast cure wounds --target @alex`."
+		}
+		explicit, name = true, strings.TrimPrefix(fields[i+1], "@")
+		fields = append(fields[:i], fields[i+2:]...)
+		break
+	}
+
+	if name == "" {
+		last := fields[len(fields)-1]
+		// A bare number is a slot level (`!cast fireball 3`), never a target.
+		if _, err := strconv.Atoi(last); err == nil {
+			return args, -1, ""
+		}
+		explicit = strings.HasPrefix(last, "@")
+		name = strings.TrimPrefix(last, "@")
+		if name == "" {
+			return args, -1, ""
+		}
+		fields = fields[:len(fields)-1]
+	}
+	// From here `fields` is the spell tokens with the target removed.
+	rest := strings.Join(fields, " ")
+
+	for i, c := range ct.players {
+		uid := ct.sess.seatUserID(i)
+		if !strings.EqualFold(c.Name, name) &&
+			!strings.EqualFold(uid, name) &&
+			!strings.EqualFold(id.UserID(uid).Localpart(), name) {
+			continue
+		}
+		if i == caster {
+			// Targeting yourself is just casting it on yourself, which is what the
+			// engine does by default. Drop the target and carry on.
+			return rest, -1, ""
+		}
+		return rest, i, ""
+	}
+	// An explicit @mention that matches nobody in the fight is a mistake worth
+	// naming — silently casting it on yourself would waste the slot.
+	if explicit {
+		return args, -1, fmt.Sprintf("**%s** isn't in this fight. Cast it on someone who is.", name)
+	}
+	return args, -1, ""
+}
+
 func (p *AdventurePlugin) castActionForSeat(ct *combatTurn, seat int, args string) (PlayerAction, func(bool), string) {
 	noop := func(bool) {}
 	uid := id.UserID(ct.sess.seatUserID(seat))
 
-	advChar, _ := loadAdvCharacter(uid)
+	// §1 — a heal may name somebody else in the fight: `!cast cure wounds @alex`.
-	c, err := p.ensureCharForDnDCmd(uid, advChar)
+	// Split the target off before the spell is parsed, so the spell parser sees
+	// the same string it always has.
+	args, targetSeat, targetErr := splitCastTarget(ct, seat, args)
+	if targetErr != "" {
+		return PlayerAction{}, noop, targetErr
+	}
+
+	c, err := p.seatCastSheet(ct.sess, uid)
 	if err != nil || c == nil {
 		return PlayerAction{}, noop, "Couldn't load your Adv 2.0 sheet."
 	}
@@ -540,7 +624,7 @@ func (p *AdventurePlugin) castActionForSeat(ct *combatTurn, seat int, args strin
 			"%s isn't a caster class. `!attack` or `!consume <item>` instead.", titleClass(c.Class))
 	}
 
-	spell, slotLevel, errMsg := parseCombatCast(uid, c, strings.TrimSpace(args))
+	spell, slotLevel, errMsg := parseCombatCast(ct.sess, seat, uid, c, strings.TrimSpace(args))
 	if errMsg != "" {
 		return PlayerAction{}, noop, errMsg
 	}
@@ -551,7 +635,7 @@ func (p *AdventurePlugin) castActionForSeat(ct *combatTurn, seat int, args strin
 
 	refund := func(ok bool) {
 		if !ok && spell.Level > 0 {
-			_ = refundSpellSlot(uid, slotLevel)
+			_ = refundSeatSlot(ct.sess, seat, uid, slotLevel)
 		}
 	}
 
@@ -568,7 +652,7 @@ func (p *AdventurePlugin) castActionForSeat(ct *combatTurn, seat int, args strin
 			return PlayerAction{}, noop, fmt.Sprintf(
 				"%s has no effect the turn-based engine can apply yet.", spell.Name)
 		}
-		if msg := p.chargeSpellCost(uid, spell, slotLevel); msg != "" {
+		if msg := p.chargeSpellCost(ct.sess, seat, uid, spell, slotLevel); msg != "" {
 			return PlayerAction{}, noop, msg
 		}
 		ct.sess.actorStatusesPtr(seat).applyBuffDelta(d)
@@ -590,7 +674,7 @@ func (p *AdventurePlugin) castActionForSeat(ct *combatTurn, seat int, args strin
 			return PlayerAction{}, noop, fmt.Sprintf(
 				"%s is a utility spell — those aren't usable in turn-based fights yet. Try a damage, healing, control, or buff spell.", spell.Name)
 		}
-		if msg := p.chargeSpellCost(uid, spell, slotLevel); msg != "" {
+		if msg := p.chargeSpellCost(ct.sess, seat, uid, spell, slotLevel); msg != "" {
 			return PlayerAction{}, noop, msg
 		}
 		// Park the Necromancy kill-heal stash on the casting seat. The
@@ -612,6 +696,20 @@ func (p *AdventurePlugin) castActionForSeat(ct *combatTurn, seat int, args strin
 			PlayerHeal:  out.PlayerHeal,
 			EnemySkip:   out.EnemySkip,
 		}
+		// §1 — redirect the heal onto the named ally. The roll is the same; only
+		// the body it lands on changes. This is the line that makes a cleric a
+		// cleric: until it existed, every heal in the engine was a self-heal, and
+		// the class whose whole job is keeping other people upright could not put
+		// a single hit point on a friend.
+		if targetSeat >= 0 && targetSeat != seat {
+			if out.PlayerHeal <= 0 {
+				return PlayerAction{}, refund, fmt.Sprintf(
+					"%s isn't something you can cast on someone else. Drop the target to cast it yourself.", spell.Name)
+			}
+			eff.AllyHeal, eff.AllySeat = out.PlayerHeal, targetSeat
+			eff.PlayerHeal = 0
+			eff.Label = fmt.Sprintf("%s → %s (+%d HP)", spell.Name, ct.players[targetSeat].Name, out.PlayerHeal)
+		}
 		// Concentration AOE damage spells linger: the burst lands this round
 		// (EnemyDamage) and the same value re-ticks every round_end after, via
 		// the engine's concentration aura. spiritual_weapon already covers the
@@ -640,18 +738,30 @@ func (p *AdventurePlugin) rebuildRoster(ct *combatTurn) error {
 // success the caller owns the slot and must refundSpellSlot if the round itself
 // errors. Material components (rare in a fight) are not refunded if the slot
 // debit then fails — matching the auto-resolve cast path.
-func (p *AdventurePlugin) chargeSpellCost(userID id.UserID, spell SpellDefinition, slotLevel int) string {
+func (p *AdventurePlugin) chargeSpellCost(sess *CombatSession, seat int, userID id.UserID, spell SpellDefinition, slotLevel int) string {
+	_, _, companion := seatCompanionLoadout(sess, userID)
+
+	// The companion carries no purse — he has no wallet to debit and no inventory
+	// to stock one from, so a component cost is not a price he can pay but a spell
+	// he cannot cast. Refusing here (rather than letting the debit fail on an empty
+	// account) keeps that an explicit rule instead of an accident of his balance.
 	if spell.MaterialCost > 0 {
+		if companion {
+			return fmt.Sprintf("%s needs a component %s doesn't carry.", spell.Name, companionDisplayName)
+		}
 		if p.euro == nil || !p.euro.Debit(userID, float64(spell.MaterialCost), "dnd_spell_component") {
 			return fmt.Sprintf("%s needs a %d-coin diamond component you can't afford.", spell.Name, spell.MaterialCost)
 		}
 	}
 	if spell.Level > 0 {
-		ok, serr := consumeSpellSlot(userID, slotLevel)
+		ok, serr := consumeSeatSlot(sess, seat, userID, slotLevel)
 		if serr != nil {
 			return "Couldn't consume slot: " + serr.Error()
 		}
 		if !ok {
+			if companion {
+				return fmt.Sprintf("%s is out of level-%d energy.", companionDisplayName, slotLevel)
+			}
 			return fmt.Sprintf("You're out of level-%d energy. %s", slotLevel, renderSlotsBrief(userID))
 		}
 	}

internal/plugin/combat_engine.go

@@ -189,6 +189,22 @@ type Combatant struct {
 	Mods     CombatModifiers
 	IsPlayer bool
 	Ability  *MonsterAbility // non-nil for monsters with a special ability
+
+	// SeatWeight is what this seat costs the enemy: 1.0 is a full peer of the
+	// leader, and less than that is a seat that brings less to the fight. Zero
+	// means "unset" and reads as 1.0, so every existing call site — and every solo
+	// fight — is unchanged.
+	//
+	// The enemy's HP bump and its action economy scale on the SUM of these rather
+	// than on a seat count. A seat count charges the boss the same for an
+	// under-levelled friend, a hired NPC, and a peer, which is why hiring a
+	// below-median body was measurably worse than going alone: he cost a full
+	// seat's worth of boss and did not give a full seat's worth back.
+	//
+	// It is derived from the seat's identity (level, and whether it is a hireling),
+	// NOT from fight state — so every per-round rebuild recomputes the same number
+	// and there is nothing to persist. See seatWeight.
+	SeatWeight float64
 }
 
 type CombatPhase struct {
@@ -220,7 +236,14 @@ type CombatEvent struct {
 	//
 	// It exists so a party's play-by-play can name the right person. Solo events
 	// are all seat 0, and the omitempty tag keeps the field out of every solo
-	// turn_log_json — rows written before N3/P5 decode unchanged.
+	// turn_log_json — rows written before N3/P5 decode unchanged, and a fight in
+	// flight across a deploy resumes byte-identically (TestP5Fields_StayOffSoloRows).
+	//
+	// The omitempty makes seat 0 and "no seat" identical on the wire, which is
+	// fine for persistence and actively misleading in a diagnostic trace — it hid
+	// a companion who never swung, making the fight look like it had one seat.
+	// Do NOT fix that here; the wire format is load-bearing. The sim's trace
+	// serializes through simTraceEvent, which always emits the seat.
 	Seat int `json:"Seat,omitempty"`
 }
 

internal/plugin/combat_engine_party.go

@@ -68,7 +68,7 @@ func simulatePartyWithRNG(players []Combatant, enemy Combatant, phases []CombatP
 	// scaled action economy to actually threaten each member. Solo is unchanged
 	// (scale 1.0), so SimulateCombat and the golden do not move.
 	if len(players) > 1 {
-		enemy.Stats.MaxHP = scaledEnemyMaxHP(enemy.Stats.MaxHP, len(players))
+		enemy.Stats.MaxHP = scaledEnemyMaxHP(enemy.Stats.MaxHP, partyWeightOf(players))
 	}
 	enemyStart := enemy.Stats.MaxHP
 	if enemy.Stats.StartHP > 0 && enemy.Stats.StartHP < enemy.Stats.MaxHP {
@@ -307,11 +307,26 @@ func roundInitiative(st *combatState, enemy *Combatant, phase *CombatPhase) []in
 // between — a per-round coin-flip for the extra action is the only way to land
 // the band in the gap. The single draw is taken only for a party, so the solo RNG
 // stream is untouched.
+// §2(b): the budget counts the seats still STANDING, re-derived every round —
+// not the seats that walked in.
+//
+// It used to read len(st.actors), which includes the dead. So a party that lost a
+// member kept paying for them: the survivor faced a boss still swinging at
+// two-player cadence, alone. That is a death spiral with the arrow pointing the
+// wrong way — the moment a party is losing, the engine hits it harder — and it is
+// the single nastiest thing the companion sweep turned up, because it is not a
+// companion bug at all. It has been live for every human party since N3.
+//
+// A corpse does not threaten anybody, and the enemy has no reason to keep spending
+// actions on one.
 func enemyActionsThisRound(st *combatState) int {
-	n := len(st.actors)
+	if livingActors(st) < 2 {
-	if n < 2 {
 		return 1
 	}
+	// The summed weight of the seats still standing — not a head count of them.
+	// A seat that brings half a peer buys the boss half a peer's worth of extra
+	// swings, and a seat that is down buys none at all.
+	n := livingWeight(st)
 	exp := partyActionExpectation(n)
 	base := int(exp)
 	if frac := exp - float64(base); frac > 0 && st.randFloat() < frac {
@@ -320,6 +335,29 @@ func enemyActionsThisRound(st *combatState) int {
 	return base
 }
 
+// livingActors counts the seats still standing.
+func livingActors(st *combatState) int {
+	n := 0
+	for _, a := range st.actors {
+		if a.playerHP > 0 {
+			n++
+		}
+	}
+	return n
+}
+
+// livingWeight is livingActors in the currency the enemy actually charges in: the
+// summed SeatWeight of the seats still standing.
+func livingWeight(st *combatState) float64 {
+	total := 0.0
+	for _, a := range st.actors {
+		if a.playerHP > 0 {
+			total += combatantWeight(a.c)
+		}
+	}
+	return total
+}
+
 // partyActionExpectation is the expected number of enemy attack-actions per round
 // against a party of n. A single enemy swing (the pre-P8 behaviour) let each
 // member absorb ~1/N² of the solo incoming and cleared 100% of T5; the sim band
@@ -333,17 +371,108 @@ func enemyActionsThisRound(st *combatState) int {
 // N≥3 follows 2N−1, the point that gave fighter ~90% / cleric-led ~72% at
 // HP ×1.15. The whole curve is monotonic by party size and never drops a
 // composition below its solo clear rate — bringing a friend is never a penalty.
-func partyActionExpectation(n int) float64 {
+// It takes a fractional party size — the summed SeatWeight of the living seats,
+// not a head count — and interpolates linearly between the integer knots the P8
+// sweep actually tuned: (1, 1.0), (2, 2.4), and 2n−1 from 3 up. Every integer
+// input therefore returns exactly what it always returned, so a solo fight and a
+// party of peers are byte-identical and the balance corpus is untouched. Only a
+// roster of *unequal* seats lands between the knots, which is the entire point:
+// a half-strength body should buy the boss half a body's worth of extra swings.
+func partyActionExpectation(n float64) float64 {
 	switch {
-	case n < 2:
+	case n <= 1:
 		return 1
-	case n == 2:
+	case n <= 2:
-		return 2.4
+		// (1, 1.0) → (2, 2.4)
+		return 1 + 1.4*(n-1)
+	case n <= 3:
+		// (2, 2.4) → (3, 5.0); the original curve stepped here, so the segment is
+		// steeper than the 2n−1 line it joins.
+		return 2.4 + 2.6*(n-2)
 	default:
-		return float64(2*n - 1)
+		return 2*n - 1
 	}
 }
 
+// seatWeight is what one seat costs the enemy, relative to the leader.
+//
+// **Level, not stats.** A power score built from HP × damage would rank a cleric
+// below a fighter and quietly make every mixed *human* party easier — the support
+// classes would stop paying their way. Level is the class-neutral measure of what
+// a body is worth, and it is exactly the axis on which the two seats that violated
+// the peer assumption differ: an under-levelled friend, and a hireling who arrives
+// a level down by design.
+//
+// A peer of the leader weighs 1.0, so a party of equals is unchanged. Nobody weighs
+// more than a peer: out-levelling the leader does not make the boss harder for
+// everyone else.
+func seatWeight(seatLevel, leaderLevel int, companion bool) float64 {
+	if leaderLevel <= 0 || seatLevel <= 0 {
+		return 1
+	}
+	w := float64(seatLevel) / float64(leaderLevel)
+	if w > 1 {
+		w = 1
+	}
+	if companion {
+		// The layers a player accumulates and a hireling never will: no subclass, no
+		// magic items, no armed ability, and gear that is never Masterwork. Levels
+		// cannot see any of that, so it is priced here.
+		w *= companionSeatWeight
+	}
+	if w < seatWeightFloor {
+		w = seatWeightFloor
+	}
+	return w
+}
+
+const (
+	// companionSeatWeight is the hireling discount — the one tunable in this model.
+	companionSeatWeight = 0.65
+	// seatWeightFloor stops a badly under-levelled seat from becoming free. A body
+	// in the fight is always worth something to the enemy: it is one more thing that
+	// has to be killed.
+	seatWeightFloor = 0.35
+)
+
+// partyWeight sums the seats' weights. An unset weight (0) reads as a full peer,
+// which is what every combatant built before this existed is.
+func partyWeight(players []*Combatant) float64 {
+	total := 0.0
+	for _, c := range players {
+		total += combatantWeight(c)
+	}
+	return total
+}
+
+func combatantWeight(c *Combatant) float64 {
+	if c == nil {
+		return 0
+	}
+	if c.SeatWeight <= 0 {
+		return 1
+	}
+	return c.SeatWeight
+}
+
+// partyWeightOf is partyWeight for a value slice.
+func partyWeightOf(players []Combatant) float64 {
+	total := 0.0
+	for i := range players {
+		total += combatantWeight(&players[i])
+	}
+	return total
+}
+
+// seatSetupWeight is partyWeight for a roster that is still being seated.
+func seatSetupWeight(seats []CombatSeatSetup) float64 {
+	total := 0.0
+	for _, s := range seats {
+		total += combatantWeight(s.C)
+	}
+	return total
+}
+
 // partyEnemyHPScale is the party-only multiplier on the enemy's max HP. Solo
 // (roster < 2) returns 1.0, so the solo path — and the characterization golden
 // and the d8prereq corpus — is byte-for-byte untouched. With the action economy
@@ -355,18 +484,27 @@ func partyActionExpectation(n int) float64 {
 // three clears the T5 martial-leader band at ~89% (fighter) / ~67% (cleric-led),
 // clearly safer than soloing (70% / 27%) but with real TPKs and member deaths —
 // not the 100% faceroll a single enemy swing produced.
-func partyEnemyHPScale(rosterSize int) float64 {
+// Like partyActionExpectation it takes the summed SeatWeight rather than a head
-	if rosterSize < 2 {
+// count, and ramps between the same knots: weight 1 (solo) pays nothing, weight 2
+// (a peer at the leader's side) pays the full 1.15 the P8 sweep tuned. Integer
+// inputs are byte-exact, so solo and a party of peers are unchanged; a roster
+// carrying a below-median body pays proportionally less, because it brought
+// proportionally less.
+func partyEnemyHPScale(weight float64) float64 {
+	if weight <= 1 {
 		return 1.0
 	}
+	if weight >= 2 {
 		return 1.15
+	}
+	return 1.0 + 0.15*(weight-1)
 }
 
 // scaledEnemyMaxHP applies the party HP scalar to a base max-HP with one rounding
 // rule, so every call site (the auto-resolve engine, the party session's initial
 // persist, and the per-turn rebuild) agrees on the same number.
-func scaledEnemyMaxHP(baseMaxHP, rosterSize int) int {
+func scaledEnemyMaxHP(baseMaxHP int, weight float64) int {
-	return int(float64(baseMaxHP) * partyEnemyHPScale(rosterSize))
+	return int(float64(baseMaxHP) * partyEnemyHPScale(weight))
 }
 
 // enemyActionPlan is the shared action budget both combat engines resolve an

internal/plugin/combat_engine_party_test.go

@@ -142,11 +142,22 @@ func TestP8PartyScaling_SoloExemptPartyScaled(t *testing.T) {
 	if got := partyActionExpectation(2); got != 2.4 {
 		t.Fatalf("duo action expectation = %v, want 2.4", got)
 	}
+	// The curve now takes a fractional weight rather than a head count, so that a
+	// below-median seat costs the enemy less than a peer does. Every INTEGER input
+	// must still return exactly what it always returned — that is what keeps solo
+	// and a party of peers byte-identical, and the balance corpus with them.
 	for n := 3; n <= 5; n++ {
-		if got, want := partyActionExpectation(n), float64(2*n-1); got != want {
+		if got, want := partyActionExpectation(float64(n)), float64(2*n-1); got != want {
 			t.Fatalf("party of %d: action expectation = %v, want %v", n, got, want)
 		}
 	}
+	// A duo carrying a half-strength body sits between soloing and a true duo.
+	if got := partyActionExpectation(1.5); got <= 1 || got >= 2.4 {
+		t.Fatalf("weight 1.5 action expectation = %v, want strictly between 1 and 2.4", got)
+	}
+	if got := partyEnemyHPScale(1.5); got <= 1.0 || got >= 1.15 {
+		t.Fatalf("weight 1.5 HP scale = %v, want strictly between 1.0 and 1.15", got)
+	}
 	if got := partyEnemyHPScale(3); got != 1.15 {
 		t.Fatalf("party HP scale = %v, want 1.15", got)
 	}

internal/plugin/combat_party_characterization_test.go

@@ -0,0 +1,159 @@
+package plugin
+
+import (
+	"flag"
+	"fmt"
+	"math/rand/v2"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// Party characterization — the net that did not exist.
+//
+// TestCombatCharacterization pins SOLO combat exhaustively, and it has been the
+// tripwire for every balance change since. Party combat had nothing. The whole
+// N-body layer — initiative order, per-seat resolution, enemy targeting, the P8
+// action-economy and HP scaling, downed-seat handling — shipped unpinned.
+//
+// What that cost: N3 shipped a Cleric class that cannot heal a single ally (no
+// action in the engine can target another seat) and not one test went red. The
+// hired companion then stood in fights doing nothing, and the unit tests stayed
+// green through that too. It took a 1500-run expedition sweep to see either.
+//
+// So: pin it. Any change to the party engine now has to state, in the diff, what
+// it moved. Regenerate ONLY on purpose:
+//
+//	go test ./internal/plugin -run TestPartyCharacterization -update
+//
+// This golden covers simulateParty — the auto-resolve engine, which decides most
+// expedition rooms and which the balance harness is built on. The turn engine's
+// party half (manual play + boss fights) needs DB fixtures and is pinned by
+// combat_turn_party_test.go; widening THAT into a golden is the follow-up.
+
+var updatePartyGolden = flag.Bool("update-party", false, "rewrite the party characterization golden")
+
+// partyScenario is one pinned N-body fight.
+type partyScenario struct {
+	name   string
+	seats  []Combatant
+	enemy  Combatant
+	phases []CombatPhase
+}
+
+// seatOfClass shapes a seat that stands in for a class archetype. These are
+// deliberately engine-level (stat blocks, not sheets): the golden pins what the
+// ENGINE does with a roster, not what the character layer feeds it.
+func seatOfClass(name string, hp, atk, def, speed int) Combatant {
+	c := basePlayer()
+	c.Name = name
+	c.Stats.MaxHP = hp
+	c.Stats.Attack = atk
+	c.Stats.Defense = def
+	c.Stats.Speed = speed
+	return c
+}
+
+func partyCharacterizationScenarios() []partyScenario {
+	tank := seatOfClass("Tank", 160, 14, 12, 8)
+	striker := seatOfClass("Striker", 90, 22, 6, 14)
+	support := seatOfClass("Support", 110, 11, 9, 10)
+	// The seat this whole plan is about: a body that is real but below median.
+	// If scaling ever stops overcharging for it, THIS line is what moves.
+	weak := seatOfClass("Weak", 70, 8, 5, 9)
+	// A seat that will fall early. Its corpse must not keep buffing the enemy —
+	// when §2 lands, this scenario is the one that proves it.
+	glass := seatOfClass("Glass", 12, 18, 0, 16)
+
+	return []partyScenario{
+		{"duo/even", []Combatant{tank, striker}, tankyEnemy(), dungeonCombatPhases},
+		{"duo/tank+support", []Combatant{tank, support}, tankyEnemy(), dungeonCombatPhases},
+		{"duo/median+weak", []Combatant{tank, weak}, tankyEnemy(), dungeonCombatPhases},
+		{"duo/glass falls early", []Combatant{tank, glass}, hardHitEnemy(), dungeonCombatPhases},
+		{"trio/even", []Combatant{tank, striker, support}, tankyEnemy(), dungeonCombatPhases},
+		{"trio/one weak seat", []Combatant{tank, striker, weak}, tankyEnemy(), dungeonCombatPhases},
+		{"trio/two glass seats", []Combatant{tank, glass, glass}, hardHitEnemy(), dungeonCombatPhases},
+		{"duo/vs ability enemy", []Combatant{tank, striker},
+			abilityEnemy("Wither", "poison", "Duel"), dungeonCombatPhases},
+		// The degenerate case. A one-seat roster MUST stay bit-identical to solo —
+		// it is the invariant the entire balance corpus rests on, and the reason
+		// the solo golden is allowed to stay untouched while this file grows.
+		{"solo/one-seat roster", []Combatant{basePlayer()}, baseEnemy(), dungeonCombatPhases},
+	}
+}
+
+// formatPartyResult prints the seat on EVERY line. The solo formatter does not
+// (it cannot; there is only one seat), and CombatEvent.Seat is `omitempty`, so a
+// JSON trace renders seat 0 and "no seat" identically — which sent me chasing a
+// phantom "the companion never swings" bug for an hour. A party golden that
+// could not tell you WHO acted would be worth very little.
+func formatPartyResult(r PartyCombatResult) string {
+	var b strings.Builder
+	fmt.Fprintf(&b, "result: won=%v timedOut=%v rounds=%d survivors=%v\n",
+		r.PlayerWon, r.TimedOut, r.TotalRounds, r.AnySurvivor())
+	fmt.Fprintf(&b, "  enemy: start=%d entry=%d end=%d\n", r.EnemyStartHP, r.EnemyEntryHP, r.EnemyEndHP)
+	for i, s := range r.Seats {
+		fmt.Fprintf(&b, "  seat[%d]: start=%d entry=%d end=%d\n",
+			i, s.PlayerStartHP, s.PlayerEntryHP, s.PlayerEndHP)
+	}
+	for i, e := range r.Events {
+		fmt.Fprintf(&b, "  [%02d] r%d seat=%d %-12s %-8s %-16s dmg=%-5d php=%-4d ehp=%-4d roll=%d/%d desc=%q\n",
+			i, e.Round, e.Seat, e.Phase, e.Actor, e.Action, e.Damage, e.PlayerHP, e.EnemyHP,
+			e.Roll, e.RollAgainst, e.Desc)
+	}
+	return b.String()
+}
+
+func TestPartyCharacterization(t *testing.T) {
+	var b strings.Builder
+	for _, sc := range partyCharacterizationScenarios() {
+		for _, seed := range charSeeds {
+			rng := rand.New(rand.NewPCG(seed, 0xC0FFEE))
+			res := simulatePartyWithRNG(sc.seats, sc.enemy, sc.phases, rng)
+			fmt.Fprintf(&b, "=== %s seed=%d ===\n", sc.name, seed)
+			b.WriteString(formatPartyResult(res))
+			b.WriteString("\n")
+		}
+	}
+	got := b.String()
+
+	path := filepath.Join("testdata", "party_characterization.golden")
+	if *updatePartyGolden {
+		if err := os.WriteFile(path, []byte(got), 0o644); err != nil {
+			t.Fatal(err)
+		}
+		t.Log("party golden rewritten:", path)
+		return
+	}
+	want, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read party golden (run with -update-party to create it): %v", err)
+	}
+	if string(want) != got {
+		t.Fatalf("PARTY ENGINE BEHAVIOUR MOVED.\n\n%s\n\n"+
+			"If this was deliberate, say so in the commit and regenerate:\n"+
+			"  go test ./internal/plugin -run TestPartyCharacterization -update-party",
+			firstDiff(string(want), got))
+	}
+}
+
+// The one-seat roster is the solo engine. If this ever fails, the N-body path has
+// stopped being a superset of the path the entire balance corpus was measured on,
+// and every baseline in the repo is suspect.
+func TestPartyCharacterization_OneSeatIsStillSolo(t *testing.T) {
+	for _, seed := range charSeeds {
+		solo := simulateCombatWithRNG(basePlayer(), baseEnemy(), dungeonCombatPhases,
+			rand.New(rand.NewPCG(seed, 0xC0FFEE)))
+		party := simulatePartyWithRNG([]Combatant{basePlayer()}, baseEnemy(), dungeonCombatPhases,
+			rand.New(rand.NewPCG(seed, 0xC0FFEE)))
+
+		if solo.PlayerWon != party.PlayerWon || solo.TotalRounds != party.TotalRounds ||
+			solo.EnemyEndHP != party.EnemyEndHP || solo.PlayerEndHP != party.Seats[0].PlayerEndHP {
+			t.Fatalf("seed %d: a one-seat roster diverged from solo\n solo:  won=%v rounds=%d ehp=%d php=%d\n party: won=%v rounds=%d ehp=%d php=%d",
+				seed,
+				solo.PlayerWon, solo.TotalRounds, solo.EnemyEndHP, solo.PlayerEndHP,
+				party.PlayerWon, party.TotalRounds, party.EnemyEndHP, party.Seats[0].PlayerEndHP)
+		}
+	}
+}

internal/plugin/combat_party_finish.go

@@ -55,6 +55,18 @@ func (p *AdventurePlugin) finishPartyCombatSession(ct *combatTurn) []string {
 	// so does the bookkeeping that outlives the fight — a Berserker who raged and
 	// lost is still exhausted. Both fan out; neither is the owner's alone.
 	for seat := range sess.RosterSize() {
+		// The companion has no sheet, so none of the sheet-keyed bookkeeping below
+		// applies to him — and postCombatBookkeepingForSeat logs at ERROR for a
+		// seat with no sheet, which would file one for every party fight he is ever
+		// hired for. But his HP is not bookkeeping: it is the fight's result. It
+		// lands on his roster row, because that is the only row he has.
+		//
+		// He used to be skipped outright, and "he arrives fresh next time" was the
+		// stated intent. It is a free lunch — see companionSeatHP.
+		if isCompanionUser(sess.seatUserID(seat)) {
+			_ = setCompanionHPForRun(sess.RunID, sess.seatHP(seat))
+			continue
+		}
 		persistDnDHPAfterCombat(id.UserID(sess.seatUserID(seat)), sess.seatHP(seat))
 		p.postCombatBookkeepingForSeat(sess, seat)
 	}
@@ -100,6 +112,16 @@ func (p *AdventurePlugin) finishPartyWin(
 		uid := id.UserID(sess.seatUserID(seat))
 		hp, hpMax := sess.seatHP(seat), sess.seatHPMax(seat)
 
+		// The hired companion takes no cut. He earns no XP (there is no sheet to
+		// put it on), rolls no loot (dropZoneLoot writes real inventory rows for
+		// whatever id it is handed, and a bot with a magic sword is nobody's
+		// intent), and takes no death row. His seat renders nothing: he is not
+		// reading this. He was paid up front.
+		if isCompanionSeat(uid) {
+			out[seat] = ""
+			continue
+		}
+
 		// A member who went down before the killing blow still earns the kill.
 		p.grantSeatWinXP(uid, hp, hpMax, monster, tier)
 
@@ -148,7 +170,17 @@ func (p *AdventurePlugin) finishPartyLoss(ct *combatTurn, zone ZoneDefinition, c
 	line := twinBeeLine(zone.ID, DMPlayerDeath, sess.RunID, cadence)
 	out := make([]string, sess.RosterSize())
 	for seat := range sess.RosterSize() {
-		markAdventureDead(id.UserID(sess.seatUserID(seat)), "zone", zone.Display)
+		uid := id.UserID(sess.seatUserID(seat))
+		// The companion does not die. markAdventureDead is a silent no-op for him
+		// today (no player_meta row to mark), but relying on that accident is how
+		// he ends up in the graveyard the first time someone gives him a row —
+		// and emitDeathNews would have the news bot file a death notice about
+		// itself. Say it out loud instead.
+		if isCompanionSeat(uid) {
+			out[seat] = ""
+			continue
+		}
+		markAdventureDead(uid, "zone", zone.Display)
 		var b strings.Builder
 		if line != "" && seat == 0 {
 			b.WriteString(line + "\n")
@@ -220,9 +252,9 @@ func endRunOnLoss(owner id.UserID, runID string, death bool) {
 		}
 	}
 	_ = abandonZoneRun(owner)
-	reason := "combat flee"
+	reason := lossCombatFlee
 	if death {
-		reason = "combat death"
+		reason = lossCombatDeath
 	}
 	forceExtractExpeditionForRunLoss(owner, reason)
 }

internal/plugin/combat_party_start.go

@@ -33,7 +33,9 @@ func fightRoster(sender id.UserID) []id.UserID {
 	if err != nil || e == nil {
 		return []id.UserID{sender}
 	}
-	return expeditionAudience(e)
+	// Seats, not audience: the hired companion fights even though he never
+	// receives a DM about it.
+	return expeditionSeats(e)
 }
 
 // buildFightSeats turns a roster into the seats that will actually sit down, and
@@ -56,9 +58,40 @@ func (p *AdventurePlugin) buildFightSeats(
 			senderSkip = why
 		}
 	}
+	// Parallel to `seats`, so a skipped member leaves no gap: what a seat costs the
+	// enemy is priced from these once the roster is final.
+	var levels []int
+	var companions []bool
 	for i, uid := range roster {
 		leader := i == 0
 
+		// The hired companion. He must be handled before everything below:
+		// dndHPSnapshot returns (0,0) for a user with no sheet, so the very next
+		// check would quietly sit him out of every fight he was paid for, and
+		// buildZoneCombatants would then fail on him anyway.
+		//
+		// He is latched onto autopilot at seat time rather than after the away-player
+		// deadline — nobody is going to type for him, and waiting three minutes to
+		// discover that would stall the fight and then announce him to the party as
+		// an absent player.
+		if isCompanionSeat(uid) {
+			expID := companionExpeditionFor(roster[0])
+			class, level := companionLoadout(expID)
+			player, _, _ := p.companionCombatant(class, level, monster, tier, dmMood)
+			// He carries his wounds between fights, like everyone else. Seating him at
+			// full max HP — which is what this did — hands the party an infinite body:
+			// he soaks a share of every fight's incoming and then resets, while the
+			// humans beside him bleed all the way to camp.
+			seats = append(seats, CombatSeatSetup{
+				UserID: uid,
+				HP:     companionSeatHP(expID, player.Stats.MaxHP),
+				HPMax:  player.Stats.MaxHP,
+				Mods:   player.Mods, C: &player, EngineDriven: true,
+			})
+			levels, companions = append(levels, level), append(companions, true)
+			continue
+		}
+
 		// Both refusals below are cheap and neither needs the build, so they run
 		// before it: consuming a seat's armed ability and *then* sitting them out
 		// would spend their rage on a fight they never joined.
@@ -94,7 +127,7 @@ func (p *AdventurePlugin) buildFightSeats(
 			trySimAutoArm(c)
 			armed = consumeArmedAbility(c)
 		}
-		player, e, _, err := p.buildZoneCombatants(uid, monster, tier, dmMood, armed)
+		player, e, dc, err := p.buildZoneCombatants(uid, monster, tier, dmMood, armed)
 		if err != nil {
 			if leader {
 				return nil, nil, "", "Couldn't set up the fight: " + err.Error()
@@ -113,7 +146,17 @@ func (p *AdventurePlugin) buildFightSeats(
 		seats = append(seats, CombatSeatSetup{
 			UserID: uid, HP: hp, HPMax: hpMax, Mods: player.Mods, C: &player, ArmedAbility: armed,
 		})
+		lvl := 0
+		if dc != nil {
+			lvl = dc.Level
 		}
+		levels, companions = append(levels, lvl), append(companions, false)
+	}
+
+	// Price each seat against the leader. It runs here, over the seats that were
+	// actually seated — a member who was skipped (downed, busy elsewhere) never
+	// joined the fight and must not be charged to the enemy.
+	applySeatWeights(seatCombatants(seats), levels, companions)
 	return seats, enemy, senderSkip, ""
 }
 
@@ -159,6 +202,12 @@ func (p *AdventurePlugin) announcePartyFightStart(
 		names[i] = c.Name
 	}
 	for seat, uid := range sess.SeatUserIDs() {
+		// Seat-keyed fan-out, so it bypasses expeditionAudience's filter — the
+		// companion sits down but is never written to. (He also has no magic items
+		// to line up, and activeMagicItemsLine would go looking for them.)
+		if isCompanionUser(uid) {
+			continue
+		}
 		var b strings.Builder
 		b.WriteString(header)
 		b.WriteString(fmt.Sprintf("You: **%d/%d HP**.\n", sess.seatHP(seat), sess.seatHPMax(seat)))

internal/plugin/combat_party_turn.go

@@ -166,6 +166,15 @@ func (p *AdventurePlugin) beginCombatTurn(sender id.UserID, noFightMsg string) (
 		return fail(notYourTurnMsg(players, acting, waiting))
 	}
 
+	// An engine-driven seat has nobody to hand the wheel back to. A command
+	// arriving from one is not a player returning to the keyboard — it is a driver
+	// impersonating a seat, which is precisely the confusion that used to strand
+	// the companion: his own auto-played turn came back through here looking like
+	// a keystroke and cleared the latch that was moving him. Refuse it outright.
+	if sess.seatIsEngineDriven(seat) {
+		return fail("That seat isn't yours to play.")
+	}
+
 	// They typed, so they are here. Hand back the wheel.
 	sess.actorStatusesPtr(seat).Autopilot = false
 
@@ -315,6 +324,33 @@ func (p *AdventurePlugin) nudgeStalledPartyTurn(sessionID string) {
 	p.announcePartyRound(ct, events, preamble, p.closePartyRound(ct))
 }
 
+// driveEngineSeat plays one engine-driven seat's turn and persists the result.
+// It is the seat-driver equivalent of a player typing `!attack`, for a seat that
+// will never type anything.
+//
+// It exists because the alternative — dispatching a combat command as that seat —
+// sends the turn back through beginCombatTurn, which reads any command from a
+// seat as "that player is back". For a human that is correct. For a seat with no
+// human it is fatal: it drops the latch that is the only thing moving them.
+func (p *AdventurePlugin) driveEngineSeat(sess *CombatSession, seat int) error {
+	players, enemy, err := p.partyCombatantsForSession(sess)
+	if err != nil {
+		return fmt.Errorf("rebuild for engine seat: %w", err)
+	}
+	ct := &combatTurn{
+		sess: sess, players: players, enemy: enemy,
+		seat: seat, uid: id.UserID(sess.seatUserID(seat)),
+	}
+	if _, err := p.runAutoSeatTurn(ct, seat); err != nil {
+		return err
+	}
+	if err := saveCombatSession(sess); err != nil {
+		return fmt.Errorf("save after engine seat turn: %w", err)
+	}
+	p.closePartyRound(ct)
+	return nil
+}
+
 // turnDeadlineLapsed reports whether the fight has sat on one member's turn past
 // partyTurnDeadline. LastActionAt is stamped by every saveCombatSession, and the
 // save that parked the fight on this seat's player_turn was the last one — so it
@@ -387,6 +423,12 @@ func (p *AdventurePlugin) announcePartyRound(ct *combatTurn, events []CombatEven
 	names := ct.seatNames()
 	acting, waiting := actingSeat(ct.sess, ct.players, ct.enemy)
 	for seat, uid := range ct.sess.SeatUserIDs() {
+		// The combat fan-out is seat-keyed, so it does not pass through
+		// expeditionAudience and does not inherit its companion filter. He fights;
+		// he is not written to about it.
+		if isCompanionUser(uid) {
+			continue
+		}
 		// Rendered once per reader: the flavor pool speaks in the second person,
 		// so each member's own events must be theirs and nobody else's.
 		body := RenderPartyTurnRound(events, names, ct.enemy.Name, seat)

internal/plugin/combat_seat_spells.go

@@ -0,0 +1,174 @@
+package plugin
+
+import (
+	"maunium.net/go/mautrix/id"
+)
+
+// Seat-scoped spellbook.
+//
+// Every spell lookup in the engine — known list, prepared flag, slot pool, slot
+// spend — is keyed on a Matrix user id and answered by a `dnd_*` table. That was
+// fine while every combatant was a player. The hired companion is not: he has no
+// row in dnd_character, dnd_known_spells or dnd_spell_slots, deliberately, because
+// a sheet on disk for him is the thing that would turn him into a real character
+// everywhere (player_meta, the leaderboard, !stats). His sheet is synthesized per
+// fight and thrown away.
+//
+// So every one of those lookups returned "nothing" for him, and the picker's very
+// first line — `c, _ := LoadDnDCharacter(uid); if c == nil { return "attack" }` —
+// sent him to swing a mace, every turn, forever. A hired Cleric could not heal.
+// Role-fill hands a lone fighter a Cleric, so that was the *common* case.
+//
+// These are the seat-scoped forms of those lookups. A human seat delegates to the
+// DB functions verbatim — same queries, same order, so solo combat and the balance
+// corpus are untouched. A companion seat is answered from his in-memory sheet and
+// a slot ledger on his seat's persisted statuses.
+//
+// Nothing here may write a row for the companion. That invariant is what
+// TestCompanion_SheetIsBelowMedianAndNeverPersisted pins, and the auto-migration
+// inside ensureCharForDnDCmd would violate it silently: handed a user with no
+// sheet, it *builds one at level 1 and saves it*. Hence seatCastSheet.
+
+// seatCompanionLoadout returns the class and level a companion seat fights as,
+// and whether the seat is the companion at all.
+func seatCompanionLoadout(sess *CombatSession, uid id.UserID) (DnDClass, int, bool) {
+	if sess == nil || !isCompanionSeat(uid) {
+		return "", 0, false
+	}
+	class, level := companionLoadoutForRun(sess.RunID)
+	return class, level, true
+}
+
+// seatCastSheet resolves the character behind a seat for the !cast path.
+//
+// A human goes through ensureCharForDnDCmd, exactly as before — including its
+// auto-migration for a player who predates Adv 2.0. The companion must NOT: that
+// migration would mint and persist a level-1 dnd_character row for him, quietly
+// making him a player and throwing away the class and level he was hired at. He
+// gets his synthetic sheet instead, built from the same class-priority pipeline a
+// real character of his level uses.
+func (p *AdventurePlugin) seatCastSheet(sess *CombatSession, uid id.UserID) (*DnDCharacter, error) {
+	if class, level, ok := seatCompanionLoadout(sess, uid); ok {
+		return companionSheet(class, level), nil
+	}
+	advChar, _ := loadAdvCharacter(uid)
+	return p.ensureCharForDnDCmd(uid, advChar)
+}
+
+// seatPickSheet is seatCastSheet for the auto-picker, which reads a sheet to
+// decide a turn and must never create one. Humans get LoadDnDCharacter, which is
+// what the picker has always called; a miss returns nil and the caller swings.
+func seatPickSheet(sess *CombatSession, uid id.UserID) *DnDCharacter {
+	if class, level, ok := seatCompanionLoadout(sess, uid); ok {
+		return companionSheet(class, level)
+	}
+	c, _ := LoadDnDCharacter(uid)
+	return c
+}
+
+// companionKnownSpells is the companion's spell list: the same default kit
+// ensureSpellsForCharacter grants a real character of that class and level, every
+// entry prepared (which is also what that function does — preparation is SP4 and
+// until it lands every granted spell is auto-prepared so !cast works).
+//
+// He gets the player kit on purpose. His below-median comes from the level penalty,
+// the never-Masterwork gear and the absent subclass/magic items — the layers a
+// player accumulates. Handing him a bespoke, weaker spell list would be a second
+// nerf hidden in a different file, and it would drift away from the tuned list the
+// moment anyone touched one and not the other.
+func companionKnownSpells(class DnDClass, level int) []knownSpellRow {
+	ids := defaultKnownSpells(class, level)
+	out := make([]knownSpellRow, 0, len(ids))
+	for _, sid := range ids {
+		out = append(out, knownSpellRow{SpellID: sid, Source: "companion", Prepared: true})
+	}
+	return out
+}
+
+// companionSlotPool is his slot table (total, used) — the class/level progression
+// every caster shares, less what he has already spent. `used` is the expedition's
+// ledger, NOT a per-fight one: he rations one pool across the run and gets it back
+// at camp, exactly as a human caster does.
+func companionSlotPool(class DnDClass, level int, used [6]int) map[int][2]int {
+	out := map[int][2]int{}
+	for lvl, total := range slotsForClassLevel(class, level) {
+		spent := 0
+		if lvl >= 0 && lvl < len(used) {
+			spent = min(used[lvl], total)
+		}
+		out[lvl] = [2]int{total, spent}
+	}
+	return out
+}
+
+// seatKnownSpells is listKnownSpells for a seat.
+func seatKnownSpells(sess *CombatSession, seat int, uid id.UserID) ([]knownSpellRow, error) {
+	if class, level, ok := seatCompanionLoadout(sess, uid); ok {
+		return companionKnownSpells(class, level), nil
+	}
+	return listKnownSpells(uid)
+}
+
+// seatSpellSlots is getSpellSlots for a seat.
+func seatSpellSlots(sess *CombatSession, seat int, uid id.UserID) (map[int][2]int, error) {
+	if class, level, ok := seatCompanionLoadout(sess, uid); ok {
+		return companionSlotPool(class, level, companionSlotsForRun(sess.RunID)), nil
+	}
+	return getSpellSlots(uid)
+}
+
+// seatKnowsSpell is playerKnowsSpell for a seat: (known, prepared, err).
+func seatKnowsSpell(sess *CombatSession, seat int, uid id.UserID, spellID string) (bool, bool, error) {
+	if _, _, ok := seatCompanionLoadout(sess, uid); ok {
+		known, err := seatKnownSpells(sess, seat, uid)
+		if err != nil {
+			return false, false, err
+		}
+		for _, k := range known {
+			if k.SpellID == spellID {
+				return true, k.Prepared, nil
+			}
+		}
+		return false, false, nil
+	}
+	return playerKnowsSpell(uid, spellID)
+}
+
+// consumeSeatSlot is consumeSpellSlot for a seat. The companion's spend lands on
+// the expedition's ledger — one pool for the whole run, refilled at camp — so he
+// rations his slots the way a human caster has to. Keying it by expedition also
+// keeps two parties who have each hired him from sharing a pool, which anything
+// keyed on his (single, shared) user id would have done.
+func consumeSeatSlot(sess *CombatSession, seat int, uid id.UserID, slotLevel int) (bool, error) {
+	class, level, ok := seatCompanionLoadout(sess, uid)
+	if !ok {
+		return consumeSpellSlot(uid, slotLevel)
+	}
+	used := companionSlotsForRun(sess.RunID)
+	if slotLevel < 1 || slotLevel >= len(used) {
+		return false, nil
+	}
+	pair, exists := companionSlotPool(class, level, used)[slotLevel]
+	if !exists || pair[0]-pair[1] <= 0 {
+		return false, nil
+	}
+	used[slotLevel]++
+	if err := setCompanionSlotsForRun(sess.RunID, used); err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+// refundSeatSlot is refundSpellSlot for a seat: the rollback half of the above,
+// called when the round the slot was spent on failed to resolve.
+func refundSeatSlot(sess *CombatSession, seat int, uid id.UserID, slotLevel int) error {
+	if _, _, ok := seatCompanionLoadout(sess, uid); !ok {
+		return refundSpellSlot(uid, slotLevel)
+	}
+	used := companionSlotsForRun(sess.RunID)
+	if slotLevel < 1 || slotLevel >= len(used) || used[slotLevel] <= 0 {
+		return nil
+	}
+	used[slotLevel]--
+	return setCompanionSlotsForRun(sess.RunID, used)
+}

internal/plugin/combat_seat_spells_test.go

@@ -0,0 +1,277 @@
+package plugin
+
+import (
+	"strings"
+	"testing"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// The hired companion casts.
+//
+// He could not, and the reason was one line: every spell lookup in the engine is
+// keyed on a user id and answered by a dnd_* table, and he has no rows in any of
+// them — deliberately, because a sheet on disk is what would turn him into a real
+// character everywhere. So the picker's first statement (`LoadDnDCharacter(uid)`)
+// came back nil and returned "attack", every turn, for the whole fight.
+//
+// Role-fill hands a lone martial a Cleric. So the common case of the feature was a
+// healer who could not heal, in a party engine that had only just learned to let
+// anyone heal anyone (§1). These pin both halves: that he picks the heal, and that
+// picking it leaves no trace of him in the database.
+
+// hireForFight seeds an expedition with the companion hired into it, and returns
+// the run id his loadout is resolved against.
+func hireForFight(t *testing.T, expID string, owner id.UserID, class DnDClass, level int) string {
+	t.Helper()
+	seedExpedition(t, expID, owner, "active")
+	seatLeaderFixture(t, expID)
+	if err := hireCompanion(expID, class, level); err != nil {
+		t.Fatalf("hireCompanion: %v", err)
+	}
+	return "run-" + expID
+}
+
+// petePartyFight seats a hurt leader and the companion, and returns the turn.
+func petePartyFight(t *testing.T, p *AdventurePlugin, runID string, leader id.UserID, leaderHP int) *combatTurn {
+	t.Helper()
+	monster := dndBestiary["goblin"]
+	lead, _, _ := p.companionCombatant(ClassFighter, 8, monster, 2, 0)
+	lead.Name = "lead"
+	pete, _, _ := p.companionCombatant(ClassCleric, 6, monster, 2, 0)
+	pete.Name = companionDisplayName
+	enemy := Combatant{Name: "x", Stats: CombatStats{MaxHP: 500, AC: 12, Attack: 4, AttackBonus: 4}}
+
+	sess, err := p.startPartyCombatSession(runID, "enc", "goblin", &enemy, []CombatSeatSetup{
+		{UserID: leader, HP: leaderHP, HPMax: 100, Mods: lead.Mods, C: &lead},
+		{UserID: companionUserID(), HP: 60, HPMax: 60, Mods: pete.Mods, C: &pete, EngineDriven: true},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return &combatTurn{
+		sess: sess, players: []*Combatant{&lead, &pete}, enemy: &enemy,
+		seat: 1, uid: companionUserID(),
+	}
+}
+
+// The headline: a hired Cleric, watching the leader bleed out, casts a heal on him.
+// Before the seat-scoped spellbook this returned ("attack", "") — he swung a mace
+// at the boss while the man who paid for him died.
+func TestCompanionSpells_HiredClericHealsTheLeader(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	leader := id.UserID("@lead:example.org")
+	runID := hireForFight(t, "exp-heal", leader, ClassCleric, 6)
+	ct := petePartyFight(t, p, runID, leader, 20) // leader at 20/100 — well under the 45% bar
+
+	kind, arg := p.pickAutoCombatActionForSeat(companionUserID(), ct.sess, 1)
+	if kind != "cast" {
+		t.Fatalf("the hired cleric picked %q %q with the leader at 20%% HP — he must heal", kind, arg)
+	}
+	if !strings.Contains(arg, "@lead") {
+		t.Fatalf("cast arg = %q, want the heal aimed at the leader's seat", arg)
+	}
+
+	// And it lands on the leader, not on himself.
+	action, settle, msg := p.castActionForSeat(ct, 1, arg)
+	if msg != "" {
+		t.Fatalf("castActionForSeat refused the companion's own pick: %s", msg)
+	}
+	settle(true)
+	eff := action.Effect
+	if eff == nil || eff.AllyHeal <= 0 {
+		t.Fatalf("effect = %+v, want an ally heal", eff)
+	}
+	if eff.AllySeat != 0 {
+		t.Errorf("heal landed on seat %d, want seat 0 (the leader)", eff.AllySeat)
+	}
+	if eff.PlayerHeal != 0 {
+		t.Errorf("the heal also healed the caster (%d HP) — it was redirected, not copied", eff.PlayerHeal)
+	}
+}
+
+// His slots are spent on his seat, and he leaves no rows behind.
+//
+// This is the invariant with teeth. castActionForSeat used to load the caster via
+// ensureCharForDnDCmd, whose auto-migration branch — handed a user with no sheet —
+// *builds one at level 1 and saves it*. Pointed at the companion that silently
+// makes him a player: a dnd_character row, a player_meta seed, a spellbook, and a
+// level-1 chassis in place of the level he was hired at.
+func TestCompanionSpells_SpendsHisSeatNotTheDatabase(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	leader := id.UserID("@lead:example.org")
+	runID := hireForFight(t, "exp-rows", leader, ClassCleric, 6)
+	ct := petePartyFight(t, p, runID, leader, 20)
+
+	action, settle, msg := p.castActionForSeat(ct, 1, "cure_wounds @lead")
+	if msg != "" {
+		t.Fatalf("the hired cleric could not cast cure wounds: %s", msg)
+	}
+	settle(true)
+	if action.Effect == nil || action.Effect.AllyHeal <= 0 {
+		t.Fatalf("effect = %+v, want an ally heal", action.Effect)
+	}
+
+	// The slot came off the expedition's ledger — which is where it has to live, so
+	// that it is still spent in the NEXT fight of the same run.
+	if used := companionSlotsForRun(ct.sess.RunID); used[1] != 1 {
+		t.Errorf("companion spent %v level-1 slots on the run's ledger, want 1", used[1])
+	}
+
+	for _, table := range []string{"dnd_character", "dnd_known_spells", "dnd_spell_slots", "player_meta"} {
+		var n int
+		if err := db.Get().QueryRow(
+			`SELECT COUNT(*) FROM `+table+` WHERE user_id = ?`, string(companionUserID()),
+		).Scan(&n); err != nil {
+			t.Fatalf("count %s: %v", table, err)
+		}
+		if n != 0 {
+			t.Errorf("casting wrote %d %s row(s) for the companion — he is not a player", n, table)
+		}
+	}
+}
+
+// He runs dry like anybody else, and then he swings. A companion with an infinite
+// spell pool is the "carry" the whole design says he must never be.
+func TestCompanionSpells_RunsOutOfSlots(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	leader := id.UserID("@lead:example.org")
+	runID := hireForFight(t, "exp-dry", leader, ClassCleric, 6)
+	ct := petePartyFight(t, p, runID, leader, 20)
+
+	total := companionSlotPool(ClassCleric, 6, [6]int{})[1][0]
+	if total <= 0 {
+		t.Fatal("a level-6 cleric has no level-1 slots — the slot table did not resolve")
+	}
+	for i := range total {
+		if ok, err := consumeSeatSlot(ct.sess, 1, companionUserID(), 1); err != nil || !ok {
+			t.Fatalf("slot %d/%d: consume = %v (%v), want it to succeed", i+1, total, ok, err)
+		}
+	}
+	if ok, _ := consumeSeatSlot(ct.sess, 1, companionUserID(), 1); ok {
+		t.Fatalf("the companion cast a %d-th level-1 spell out of a %d-slot pool", total+1, total)
+	}
+
+	// The refund half: a round that fails to resolve gives the slot back.
+	if err := refundSeatSlot(ct.sess, 1, companionUserID(), 1); err != nil {
+		t.Fatal(err)
+	}
+	if ok, _ := consumeSeatSlot(ct.sess, 1, companionUserID(), 1); !ok {
+		t.Error("a refunded slot was not castable again")
+	}
+}
+
+// His pool does NOT refill between fights, and it DOES come back at camp.
+//
+// This is the one the sweep caught and the unit tests did not. The first cut of
+// the spellbook parked his ledger on his combat seat — and a seat is per-session,
+// so every fight opened a fresh one and he walked in with full slots. A human
+// cleric rations a single pool across the whole run; rationing it IS the caster's
+// game. Handed an infinite pool, a gearless level-penalized hireling out-cleared a
+// same-level human cleric by 15pp in the sim.
+func TestCompanionSpells_PoolIsRationedAcrossTheRun(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	leader := id.UserID("@lead:example.org")
+	runID := hireForFight(t, "exp-ration", leader, ClassCleric, 6)
+
+	// Fight one: spend every level-1 slot he owns.
+	first := petePartyFight(t, p, runID, leader, 20)
+	total := companionSlotPool(ClassCleric, 6, [6]int{})[1][0]
+	for range total {
+		if ok, err := consumeSeatSlot(first.sess, 1, companionUserID(), 1); err != nil || !ok {
+			t.Fatalf("consume: %v (%v)", ok, err)
+		}
+	}
+
+	// Fight two, same run — a NEW combat session, which is exactly what used to
+	// hand him a fresh pool.
+	if err := markCombatSessionExpired(first.sess.SessionID); err != nil {
+		t.Fatal(err)
+	}
+	second := petePartyFight(t, p, runID, leader, 20)
+	if ok, _ := consumeSeatSlot(second.sess, 1, companionUserID(), 1); ok {
+		t.Error("the companion's spell slots refilled between fights — he is an infinite caster")
+	}
+
+	// ...and camp gives them back, the same way it does for every human.
+	if err := refreshCompanionSlots("exp-ration"); err != nil {
+		t.Fatal(err)
+	}
+	if ok, _ := consumeSeatSlot(second.sess, 1, companionUserID(), 1); !ok {
+		t.Error("camp did not restore the companion's slots — his pool only ever goes down")
+	}
+}
+
+// He carries his wounds between fights, and camp patches him up.
+//
+// He used to re-seat at full max HP for every single fight — "he arrives fresh
+// next time" was the close-out's stated intent — which is an infinite body. A
+// player bleeds across a 30-room run and only heals at camp; the hireling soaked
+// his share of every fight and then reset. In the sim his party fled 5 runs out of
+// 640 where the same party with a *human* cleric fled 56.
+func TestCompanion_CarriesWoundsBetweenFights(t *testing.T) {
+	setupEmptyTestDB(t)
+	leader := id.UserID("@lead:example.org")
+	seedExpedition(t, "exp-hp", leader, "active")
+	seatLeaderFixture(t, "exp-hp")
+	if err := hireCompanion("exp-hp", ClassCleric, 6); err != nil {
+		t.Fatal(err)
+	}
+
+	// A fresh hire is at full.
+	if got := companionSeatHP("exp-hp", 100); got != 100 {
+		t.Errorf("a fresh hire seats at %d/100 HP, want full", got)
+	}
+
+	// He walks out of a fight on 30 HP; he walks into the next one on 30 HP.
+	if err := setCompanionHP("exp-hp", 30); err != nil {
+		t.Fatal(err)
+	}
+	if got := companionSeatHP("exp-hp", 100); got != 30 {
+		t.Errorf("he re-seated at %d/100 HP after ending a fight on 30 — the wound did not carry", got)
+	}
+
+	// Dropped in a fight, he comes back on his feet but barely — not as a corpse
+	// (there is no companion-death rule) and not at full.
+	if err := setCompanionHP("exp-hp", 0); err != nil {
+		t.Fatal(err)
+	}
+	if got := companionSeatHP("exp-hp", 100); got != 1 {
+		t.Errorf("after being dropped he seats at %d/100 HP, want 1", got)
+	}
+
+	// Camp puts him right, exactly as it does every human.
+	if err := refreshCompanionHP("exp-hp"); err != nil {
+		t.Fatal(err)
+	}
+	if got := companionSeatHP("exp-hp", 100); got != 100 {
+		t.Errorf("camp left him on %d/100 HP — his body only ever goes down", got)
+	}
+}
+
+// A hired martial is still a martial: the spellbook is the class's, not a blanket
+// grant, so hiring a Fighter does not quietly buy a caster.
+func TestCompanionSpells_MartialHasNoSpellbook(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	leader := id.UserID("@lead:example.org")
+	runID := hireForFight(t, "exp-mart", leader, ClassFighter, 6)
+	ct := petePartyFight(t, p, runID, leader, 20)
+
+	if known, _ := seatKnownSpells(ct.sess, 1, companionUserID()); len(known) != 0 {
+		t.Errorf("a hired Fighter knows %d spells, want none", len(known))
+	}
+	if _, _, msg := p.castActionForSeat(ct, 1, "cure_wounds @lead"); msg == "" {
+		t.Error("a hired Fighter cast cure wounds")
+	}
+	kind, _ := p.pickAutoCombatActionForSeat(companionUserID(), ct.sess, 1)
+	if kind != "attack" {
+		t.Errorf("a hired Fighter picked %q, want attack", kind)
+	}
+}

internal/plugin/combat_seat_weight_test.go

@@ -0,0 +1,108 @@
+package plugin
+
+import "testing"
+
+// §2(a) — the enemy charges for what a seat BRINGS, not for the fact that it sat
+// down.
+//
+// Both scaling levers (the +15% boss HP and the 1 → 2.4 attacks-a-round action
+// economy) counted seats. A seat count charges the same for an under-levelled
+// friend, a hired NPC, and a true peer — so a below-median body cost a full seat's
+// worth of boss and did not give a full seat's worth back. Measured: hiring the
+// companion was *worse than going alone* (66.1% against solo's 69.0%) once his
+// free full-heal was taken away.
+//
+// The invariant that makes this safe to ship: every seat that IS a peer still
+// weighs exactly 1.0, so solo and a party of equals are byte-identical and the
+// balance corpus does not move. Only an unequal roster lands between the knots.
+
+func TestSeatWeight_APeerWeighsExactlyOne(t *testing.T) {
+	// The leader, and a friend of the leader's level: both full price.
+	if got := seatWeight(10, 10, false); got != 1.0 {
+		t.Errorf("a peer weighs %v, want exactly 1.0 — a party of equals must not move", got)
+	}
+	// Out-levelling the leader does not make the boss harder for everybody else.
+	if got := seatWeight(14, 10, false); got != 1.0 {
+		t.Errorf("a higher-level friend weighs %v, want 1.0 (capped)", got)
+	}
+}
+
+func TestSeatWeight_TheUnderLevelledAndTheHiredCostLess(t *testing.T) {
+	// The under-levelled friend — the case that has nothing to do with the
+	// companion and has been live since parties shipped.
+	half := seatWeight(5, 10, false)
+	if half >= 1.0 || half <= seatWeightFloor {
+		t.Errorf("a level-5 friend of a level-10 leader weighs %v, want between the floor and 1.0", half)
+	}
+	// The hireling pays the same level penalty AND the discount for everything a
+	// player accrues that he never will (subclass, magic items, Masterwork gear).
+	hired := seatWeight(9, 10, true)
+	peerAtSameLevel := seatWeight(9, 10, false)
+	if hired >= peerAtSameLevel {
+		t.Errorf("the hireling weighs %v and a human of his level weighs %v — he must cost the enemy less",
+			hired, peerAtSameLevel)
+	}
+	// But a body is never free: it is still one more thing the boss has to kill.
+	if got := seatWeight(1, 20, true); got < seatWeightFloor {
+		t.Errorf("a hopelessly under-levelled hireling weighs %v, below the floor %v", got, seatWeightFloor)
+	}
+}
+
+// The levers themselves: integer knots byte-exact, fractions in between.
+func TestSeatWeight_ScalingIsExactAtThePeerKnots(t *testing.T) {
+	// Solo and a party of peers reproduce the pre-§2(a) numbers exactly. This is
+	// the whole safety argument — if either of these drifts, the corpus is invalid.
+	for _, tc := range []struct {
+		weight float64
+		acts   float64
+		hp     float64
+	}{
+		{1, 1, 1.0},    // solo
+		{2, 2.4, 1.15}, // a duo of peers
+		{3, 5, 1.15},   // a trio of peers
+	} {
+		if got := partyActionExpectation(tc.weight); got != tc.acts {
+			t.Errorf("weight %v: enemy actions = %v, want exactly %v", tc.weight, got, tc.acts)
+		}
+		if got := partyEnemyHPScale(tc.weight); got != tc.hp {
+			t.Errorf("weight %v: enemy HP scale = %v, want exactly %v", tc.weight, got, tc.hp)
+		}
+	}
+
+	// A leader plus a hireling is strictly cheaper than a leader plus a peer, and
+	// strictly dearer than soloing. Bringing him must cost the boss *something* —
+	// that is what stops a free body from becoming a carry.
+	duoWithHire := 1 + seatWeight(9, 10, true)
+	if a := partyActionExpectation(duoWithHire); a <= 1 || a >= 2.4 {
+		t.Errorf("leader + hireling buys the enemy %v actions, want strictly between 1 and 2.4", a)
+	}
+	if h := partyEnemyHPScale(duoWithHire); h <= 1.0 || h >= 1.15 {
+		t.Errorf("leader + hireling scales boss HP by %v, want strictly between 1.0 and 1.15", h)
+	}
+}
+
+// A seat that is DOWN buys the enemy nothing. §2(b) fixed the head-count half of
+// this; the weight half has to hold too, or a corpse keeps paying for swings.
+func TestSeatWeight_TheDeadBuyTheEnemyNothing(t *testing.T) {
+	alive := &Combatant{SeatWeight: 1}
+	hire := &Combatant{SeatWeight: 0.6}
+	st := &combatState{actors: []*actor{
+		{c: alive, playerHP: 40},
+		{c: hire, playerHP: 0}, // dropped
+	}}
+	if got := livingWeight(st); got != 1 {
+		t.Errorf("living weight with a downed hireling = %v, want 1 (only the survivor pays)", got)
+	}
+	st.actors[1].playerHP = 20
+	if got := livingWeight(st); got != 1.6 {
+		t.Errorf("living weight with the hireling up = %v, want 1.6", got)
+	}
+}
+
+// An unset weight reads as a full peer, so every combatant built before this
+// existed — and every test that builds one by hand — is priced exactly as before.
+func TestSeatWeight_UnsetIsAPeer(t *testing.T) {
+	if got := combatantWeight(&Combatant{}); got != 1 {
+		t.Errorf("a combatant with no weight set counts %v, want 1", got)
+	}
+}

internal/plugin/combat_session.go

@@ -121,7 +121,7 @@ type ActorStatuses struct {
 	// fight, set when its turn deadline lapses once (see partyTurnDeadline).
 	// Without the latch an away member taxes the party the full deadline every
 	// single round; with it, they cost one wait and then resolve instantly. Any
-	// combat command from that member clears it.
+	// combat command from that member clears it — they typed, so they are back.
 	//
 	// Like the Buff* deltas it is session-layer state with no combatState
 	// counterpart, so snapshotActor carries it over from the prior snapshot
@@ -129,6 +129,24 @@ type ActorStatuses struct {
 	// fight has no turn deadline, only the 1h session reaper.
 	Autopilot bool `json:"autopilot,omitempty"`
 
+	// EngineDriven marks a seat that has NO human behind it and never will: a
+	// hired companion today, an NPC ally or a Pete-led expedition tomorrow. It is
+	// the answer to "who owns this turn", and it is deliberately NOT the same
+	// question as Autopilot.
+	//
+	// Autopilot means "a human is away"; it is provisional, and a keystroke ends
+	// it. EngineDriven means "there is nobody to come back", and nothing clears it.
+	// Collapsing the two is a bug with teeth: the expedition autopilot drives a
+	// party by dispatching each seat's turn as a command from that seat, so an
+	// engine seat's own auto-played move arrived back at beginCombatTurn looking
+	// exactly like a player returning to the keyboard, and cleared the very latch
+	// that was moving it. The seat then stood in the fight doing nothing for the
+	// rest of the fight — while the enemy it had inflated by 15% killed the party.
+	//
+	// So the property lives on the seat, not on an identity check, and no command
+	// path can unset it.
+	EngineDriven bool `json:"engine_driven,omitempty"`
+
 	// Debuffs the enemy has stacked onto this character specifically.
 	PlayerAtkDrain int `json:"player_atk_drain,omitempty"`
 	PlayerACDebuff int `json:"player_ac_debuff,omitempty"`
@@ -256,7 +274,8 @@ func seedActorOneShots(st *ActorStatuses, seat CombatSeatSetup) bool {
 	st.ArcaneWardHP = playerMods.ArcaneWardHP
 	st.HealChargesLeft = playerMods.HealItemCharges
 	st.ArmedAbility = seat.ArmedAbility
-	return st.WardCharges != 0 || st.SporeRounds != 0 || st.ReflectFrac != 0 ||
+	st.EngineDriven = seat.EngineDriven
+	return st.EngineDriven || st.WardCharges != 0 || st.SporeRounds != 0 || st.ReflectFrac != 0 ||
 		st.AutoCritFirst || st.ArcaneWardHP != 0 || st.HealChargesLeft != 0 ||
 		st.ArmedAbility != ""
 }
@@ -387,16 +406,30 @@ func (s *CombatSession) seatOf(userID id.UserID) (int, bool) {
 // turn silently rather than blocking the round on a corpse.
 func (s *CombatSession) seatAlive(seat int) bool { return s.seatHP(seat) > 0 }
 
-// seatIsAutopiloted reports whether a seat has been latched onto the auto-picker
+// seatIsEngineDriven reports whether a seat has no human behind it at all — a
-// by a lapsed turn deadline.
+// hired companion, an NPC ally. Permanent for the life of the fight; no command
+// clears it. Contrast seatIsAutopiloted, which is a human who stepped away.
+func (s *CombatSession) seatIsEngineDriven(seat int) bool {
+	return s.actorStatusesForSeat(seat).EngineDriven
+}
+
+// seatIsAutopiloted reports whether the engine, rather than a person, decides
+// this seat's action — because its human is away (a lapsed turn deadline) or
+// because it never had one.
+//
+// Every driver in the codebase reads this, which is exactly why the two reasons
+// share one accessor: the picker does not care WHY nobody is typing. What differs
+// is who is allowed to take the wheel back, and that question is asked in
+// beginCombatTurn against seatIsEngineDriven — never here.
 func (s *CombatSession) seatIsAutopiloted(seat int) bool {
-	return s.actorStatusesForSeat(seat).Autopilot
+	st := s.actorStatusesForSeat(seat)
+	return st.Autopilot || st.EngineDriven
 }
 
 // seatNeedsNoHuman reports whether the engine can resolve a seat's turn without
-// waiting on its player: it is down (forfeits silently) or latched onto
+// waiting on its player: it is down (forfeits silently), latched onto autopilot,
-// autopilot. driveCombatRound keeps stepping while this holds, so a round only
+// or has no human to wait for. driveCombatRound keeps stepping while this holds,
-// comes to rest on a live human's turn.
+// so a round only comes to rest on a live human's turn.
 func (s *CombatSession) seatNeedsNoHuman(seat int) bool {
 	return !s.seatAlive(seat) || s.seatIsAutopiloted(seat)
 }
@@ -491,7 +524,7 @@ func (p *AdventurePlugin) startPartyCombatSession(
 	// Party-only enemy HP bump (solo roster scales by 1.0). The per-turn rebuild
 	// in partyCombatantsForSession applies the identical scalar to the enemy's
 	// Stats.MaxHP, so the persisted current HP and the rebuilt max never drift.
-	enemyHP := scaledEnemyMaxHP(enemy.Stats.MaxHP, len(seats))
+	enemyHP := scaledEnemyMaxHP(enemy.Stats.MaxHP, seatSetupWeight(seats))
 	owner := seats[0]
 	sess, err := startCombatSession(owner.UserID, runID, encounterID, enemyID,
 		owner.HP, owner.HPMax, enemyHP, enemyHP)
@@ -553,6 +586,12 @@ type CombatSeatSetup struct {
 	// if they armed nothing. It is persisted onto the seat's statuses so every
 	// later rebuild can re-apply the ability without re-spending it.
 	ArmedAbility string
+	// EngineDriven seats this combatant with no human behind it — the hired
+	// companion today. It resolves from the opening round rather than after the
+	// 3-minute away-player deadline (nobody is coming, so waiting out a deadline
+	// would idle the fight and then announce him to the party as absent), and no
+	// command can hand the wheel back to a player who does not exist.
+	EngineDriven bool
 }
 
 // getActiveCombatSession returns the player's in-flight fight, or (nil, nil).

internal/plugin/combat_session_build.go

@@ -154,13 +154,36 @@ func (p *AdventurePlugin) partyCombatantsForSession(sess *CombatSession) ([]*Com
 
 	seats := sess.SeatUserIDs()
 	players := make([]*Combatant, len(seats))
+	levels := make([]int, len(seats))
+	companions := make([]bool, len(seats))
 	var enemy Combatant
 	for seat, uid := range seats {
 		// The ability this seat armed was consumed once, at fight start, and its
 		// id parked on their statuses. Re-applying it here — not re-consuming —
 		// is what makes a rage last the whole fight instead of one round.
 		st := sess.actorStatusesForSeat(seat)
-		player, e, _, err := p.buildZoneCombatants(id.UserID(uid), monster, int(zone.Tier), run.DMMood, st.ArmedAbility)
+
+		// The hired companion has no sheet to load — by design, because a
+		// player_meta row for him is the thing that would turn him into a real
+		// character everywhere. Synthesize his seat instead. This branch is
+		// load-bearing: buildZoneCombatants would fail on him, and one
+		// unbuildable seat fails the whole rebuild, which is what every human's
+		// !attack in the fight depends on.
+		if isCompanionUser(uid) {
+			class, level := companionLoadoutForRun(sess.RunID)
+			player, en, _ := p.companionCombatant(class, level, monster, int(zone.Tier), run.DMMood)
+			applySessionBuffs(&player, st)
+			players[seat] = &player
+			levels[seat], companions[seat] = level, true
+			if seat == 0 {
+				// Unreachable today (seat 0 is always the leader), but if it ever
+				// isn't, the enemy still has to come from somewhere.
+				enemy = en
+			}
+			continue
+		}
+
+		player, e, dc, err := p.buildZoneCombatants(id.UserID(uid), monster, int(zone.Tier), run.DMMood, st.ArmedAbility)
 		if err != nil {
 			return nil, nil, fmt.Errorf("seat %d (%s): %w", seat, uid, err)
 		}
@@ -171,22 +194,47 @@ func (p *AdventurePlugin) partyCombatantsForSession(sess *CombatSession) ([]*Com
 		// stat deltas are applied here — and only that seat's own.
 		applySessionBuffs(&player, st)
 		players[seat] = &player
+		if dc != nil {
+			levels[seat] = dc.Level
+		}
 		if seat == 0 {
 			// The enemy build reads only (monster, tier, dmMood): every seat
 			// rebuilds the identical stat block, so seat 0's copy is the fight's.
 			// Only the *player* half of the build varies by seat.
 			enemy = e
-			// Party-only enemy HP bump, re-derived each turn from the template so
+		}
-			// it never compounds. Matches the scalar startPartyCombatSession used
+	}
-			// for the initial persist; solo (roster 1) scales by 1.0.
+
+	// What each seat costs the enemy, priced against the leader. This runs after
+	// the loop and not inside it, because a seat's weight is relative to seat 0's
+	// level and the enemy's HP is scaled off the *summed* weight — neither is known
+	// until every seat is built.
+	applySeatWeights(players, levels, companions)
+
+	// Party-only enemy HP bump, re-derived each turn from the template so it never
+	// compounds. Matches the scalar startPartyCombatSession used for the initial
+	// persist; solo (one seat, weight 1) scales by 1.0.
 	if sess.IsParty() {
-				enemy.Stats.MaxHP = scaledEnemyMaxHP(enemy.Stats.MaxHP, sess.RosterSize())
+		enemy.Stats.MaxHP = scaledEnemyMaxHP(enemy.Stats.MaxHP, partyWeight(players))
-			}
-		}
 	}
 	return players, &enemy, nil
 }
 
+// applySeatWeights prices every seat against the leader's level. Seat 0 is the
+// leader and always weighs a full 1.0.
+func applySeatWeights(players []*Combatant, levels []int, companions []bool) {
+	if len(players) == 0 {
+		return
+	}
+	leaderLevel := levels[0]
+	for i, c := range players {
+		if c == nil {
+			continue
+		}
+		c.SeatWeight = seatWeight(levels[i], leaderLevel, companions[i])
+	}
+}
+
 // seatFightStartMods re-derives the modifiers a finished fight's close-out still
 // needs: the Berserker's rage flag, which decides whether the character owes a
 // point of exhaustion, and the Necromancy Mage's Grim Harvest stash.

internal/plugin/combat_turn_engine.go

@@ -65,6 +65,19 @@ type turnActionEffect struct {
 	EnemyDamage int
 	PlayerHeal  int
 	EnemySkip   bool // control spell: enemy forfeits its attack this round
+
+	// AllyHeal heals ANOTHER seat instead of the caster — the thing the engine
+	// could not do until §1, and the reason a party cleric was a cleric in name
+	// only. Every heal in the engine wrote to the acting seat: MistyHealProc,
+	// HealItem, PlayerHeal above. Nothing could put a hit point on a friend, so
+	// the class whose entire identity is keeping other people alive could not.
+	// N3 shipped that way and no test noticed, because there was no party golden.
+	//
+	// Zero means no ally heal, which keeps every existing construction of this
+	// struct meaning exactly what it meant before. AllySeat is only read when
+	// AllyHeal > 0, so its zero value is never mistaken for "seat 0".
+	AllyHeal int
+	AllySeat int
 	// ConcentrationDmg arms a per-round aura tick when a concentration damage
 	// spell is cast: EnemyDamage is the burst that lands this round, this is
 	// what re-ticks at every round_end after. Zero for one-shot spells; a
@@ -560,6 +573,25 @@ func (te *turnEngine) stepPlayerActionEffect(eff *turnActionEffect) {
 		hpCap := max(1, st.hpMax-st.maxHPDrain)
 		st.playerHP = min(hpCap, st.playerHP+eff.PlayerHeal)
 	}
+	// §1 — heal somebody else. The caster's cursor stays where it is; only the
+	// target's HP moves.
+	//
+	// A downed seat is NOT raised. Death in this engine is terminal for the fight
+	// (the close-out marks them, the hospital takes them), and a heal that
+	// resurrected a corpse would quietly rewrite the loss rules every close-out
+	// path depends on. Healing keeps people up; it does not bring them back.
+	if eff.AllyHeal > 0 && eff.AllySeat >= 0 && eff.AllySeat < len(st.actors) {
+		if tgt := st.actors[eff.AllySeat]; tgt.playerHP > 0 {
+			cap := max(1, tgt.hpMax-tgt.maxHPDrain)
+			before := tgt.playerHP
+			tgt.playerHP = min(cap, tgt.playerHP+eff.AllyHeal)
+			st.events = append(st.events, CombatEvent{
+				Round: st.round, Phase: turnCombatPhase.Name, Actor: "player", Action: "ally_heal",
+				Damage: tgt.playerHP - before, PlayerHP: tgt.playerHP, EnemyHP: st.enemyHP,
+				Seat: eff.AllySeat, Desc: eff.Label,
+			})
+		}
+	}
 	// Arm / replace the concentration aura. A new concentration cast overwrites
 	// the old one (5e: one concentration at a time); non-concentration casts
 	// leave any running aura alone.

internal/plugin/dnd_cast.go

@@ -1,7 +1,9 @@
 package plugin
 
 import (
+	"database/sql"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log/slog"
 	"math/rand/v2"
@@ -27,9 +29,11 @@ import (
 //   - Reaction spells (Shield, Counterspell, Absorb Elements) refuse with
 //     a "Phase 11" note — they require the boss turn-based engine.
 //
-// Cross-player targeting (--target @user) is deliberately deferred. SP2
+// Cross-player targeting (`--target @user`, or a trailing `@user`) heals a human
-// supports self-target only. Heals on self work; ally buffs queue with the
+// on your expedition — see dnd_cast_target.go. Only heals may name somebody else
-// caster as the target until SP3 wires up the multi-player resolution.
+// out of combat: UTILITY resolves on the caster, and everything else queues as a
+// PendingCast for the *caster's* next fight, where an ally target has nothing to
+// mean. In-combat targeting is splitCastTarget (combat_cmd.go).
 
 // PendingCast is the shape stored in dnd_character.pending_cast (JSON blob).
 // Keep this minimal — the combat layer resolves the actual numbers on fire.
@@ -97,6 +101,13 @@ func (p *AdventurePlugin) handleDnDCastCmd(ctx MessageContext, args string) erro
 		return p.dndCastDrop(ctx, c)
 	}
 
+	// An ally target — `--target @alex`, or a trailing `@alex` — comes off the
+	// string before the spell parser sees it, exactly as in combat. It is
+	// resolved (and refused) further down, once we know the spell is a heal: a
+	// target on anything else is a mistake, and refusing it early would cost us
+	// the "which spell?" half of the error message.
+	args, targetName := splitOutOfCombatTarget(args)
+
 	// Parse spell name + optional --upcast N.
 	tokens := strings.Fields(args)
 	upcast := 0
@@ -111,11 +122,6 @@ func (p *AdventurePlugin) handleDnDCastCmd(ctx MessageContext, args string) erro
 				}
 				i++
 			}
-		case "--target":
-			// Reserved for SP3 — accept and ignore for now.
-			if i+1 < len(tokens) {
-				i++
-			}
 		default:
 			spellTokens = append(spellTokens, tokens[i])
 		}
@@ -195,6 +201,23 @@ func (p *AdventurePlugin) handleDnDCastCmd(ctx MessageContext, args string) erro
 		}
 	}
 
+	// Resolve an ally target now — BEFORE anything is spent. Out of combat only a
+	// heal can land on somebody else: UTILITY resolves on the caster and
+	// everything else queues as a PendingCast for *this* caster's next fight, so
+	// a target on those would be accepted and then silently dropped.
+	var targetUser id.UserID
+	if targetName != "" {
+		if spell.Effect != EffectSpellHeal {
+			return p.SendDM(ctx.Sender, fmt.Sprintf(
+				"%s isn't a healing spell — outside a fight you can only cast those on someone else. Drop the target to cast it on yourself.", spell.Name))
+		}
+		uid, errMsg := resolveCastTargetOnExpedition(ctx.Sender, targetName)
+		if errMsg != "" {
+			return p.SendDM(ctx.Sender, errMsg)
+		}
+		targetUser = uid // empty when they named themselves — self-heal as usual
+	}
+
 	// Material cost (Revivify, Raise Dead).
 	if spell.MaterialCost > 0 {
 		if p.euro == nil || !p.euro.Debit(ctx.Sender, float64(spell.MaterialCost), "dnd_spell_component") {
@@ -220,6 +243,9 @@ func (p *AdventurePlugin) handleDnDCastCmd(ctx MessageContext, args string) erro
 	// debited above; if SaveDnDCharacter fails we refund.
 	switch spell.Effect {
 	case EffectSpellHeal:
+		if targetUser != "" {
+			return p.resolveAllyHealOutOfCombat(ctx, c, targetUser, spell, slotLevel)
+		}
 		return p.resolveHealOutOfCombat(ctx, c, spell, slotLevel)
 	case EffectUtility:
 		return p.resolveUtility(ctx, c, spell, slotLevel)
@@ -231,7 +257,10 @@ func (p *AdventurePlugin) handleDnDCastCmd(ctx MessageContext, args string) erro
 
 // ── Out-of-combat: HEAL ──────────────────────────────────────────────────────
 
-func (p *AdventurePlugin) resolveHealOutOfCombat(ctx MessageContext, c *DnDCharacter, spell SpellDefinition, slotLevel int) error {
+// rollOutOfCombatHeal is what the spell is worth in the caster's hands. It is a
+// property of the caster (their WIS, their domain), never of the body it lands
+// on, so an ally heal rolls exactly the same as a self-heal.
+func rollOutOfCombatHeal(c *DnDCharacter, spell SpellDefinition, slotLevel int) int {
 	dice, faces, _ := parseDamageDice(spell.DamageDice)
 	if dice == 0 {
 		dice, faces = 1, 8 // safety fallback
@@ -253,6 +282,11 @@ func (p *AdventurePlugin) resolveHealOutOfCombat(ctx MessageContext, c *DnDChara
 	}
 	heal += abilityModifier(c.WIS)
 	heal += lifeDomainHealBonus(c, spell, slotLevel)
+	return heal
+}
+
+func (p *AdventurePlugin) resolveHealOutOfCombat(ctx MessageContext, c *DnDCharacter, spell SpellDefinition, slotLevel int) error {
+	heal := rollOutOfCombatHeal(c, spell, slotLevel)
 
 	before := c.HPCurrent
 	c.HPCurrent = min(c.HPMax, c.HPCurrent+heal)
@@ -272,6 +306,51 @@ func (p *AdventurePlugin) resolveHealOutOfCombat(ctx MessageContext, c *DnDChara
 		renderSlotsBrief(ctx.Sender)))
 }
 
+// resolveAllyHealOutOfCombat puts the heal on somebody else's sheet. The slot is
+// already spent, so every failure below refunds it: a heal that lands on nobody
+// must not cost the caster anything.
+func (p *AdventurePlugin) resolveAllyHealOutOfCombat(ctx MessageContext, c *DnDCharacter, target id.UserID, spell SpellDefinition, slotLevel int) error {
+	refund := func(msg string) error {
+		if spell.Level > 0 {
+			_ = refundSpellSlot(ctx.Sender, slotLevel)
+		}
+		return p.SendDM(ctx.Sender, msg)
+	}
+
+	heal := rollOutOfCombatHeal(c, spell, slotLevel)
+	before, after, maxHP, err := healPartyMember(target, heal)
+
+	targetName := charName(target)
+	if targetName == "" {
+		targetName = target.Localpart()
+	}
+	casterName := charName(ctx.Sender)
+	if casterName == "" {
+		casterName = ctx.Sender.Localpart()
+	}
+
+	switch {
+	case errors.Is(err, errHealTargetFull):
+		return refund(fmt.Sprintf("**%s** is already at full health (%d/%d). Slot kept.", targetName, before, maxHP))
+	case errors.Is(err, errHealTargetDown):
+		// The same rule the combat path holds: a heal is not a resurrection.
+		return refund(fmt.Sprintf("**%s** is down — a heal won't bring them back. Slot kept.", targetName))
+	case errors.Is(err, sql.ErrNoRows):
+		return refund(fmt.Sprintf("**%s** hasn't run `!setup` yet, so there's no sheet to heal.", targetName))
+	case err != nil:
+		return refund("Couldn't apply the heal: " + err.Error())
+	}
+
+	_ = p.SendDM(target, fmt.Sprintf(
+		"🩹 **%s** casts **%s** on you — %d HP back (%d → %d / %d).",
+		casterName, spell.Name, after-before, before, after, maxHP))
+
+	return p.SendDM(ctx.Sender, fmt.Sprintf(
+		"🩹 **%s** on **%s** — restored %d HP (%d → %d / %d). %s",
+		spell.Name, targetName, after-before, before, after, maxHP,
+		renderSlotsBrief(ctx.Sender)))
+}
+
 // ── Out-of-combat: UTILITY ──────────────────────────────────────────────────
 
 func (p *AdventurePlugin) resolveUtility(ctx MessageContext, c *DnDCharacter, spell SpellDefinition, slotLevel int) error {
@@ -676,6 +755,7 @@ func renderCastHelp(c *DnDCharacter) string {
 	var b strings.Builder
 	b.WriteString("**Cast a spell**\n\n")
 	b.WriteString("Usage: `!cast <spell> [--upcast N]`\n")
+	b.WriteString("       `!cast <heal> @friend` to heal someone on your expedition.\n")
 	b.WriteString("       `!cast --drop` to clear queued/concentration.\n\n")
 	b.WriteString("Run `!spells` for your full list.\n\n")
 	if pc, ok := decodePendingCast(c.PendingCast); ok {

internal/plugin/dnd_cast_ally_e2e_test.go

@@ -0,0 +1,139 @@
+package plugin
+
+import (
+	"testing"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// The whole `!cast cure wounds @friend` path, out of combat, through the real
+// handler: parse → class/known/prepared gates → slot debit → the ally's sheet.
+//
+// The seams are unit-tested next door; this exists for the one thing they cannot
+// see — that the slot ledger and the HP write agree about whether the heal
+// happened. A refund that does not fire is a slot a player paid for nothing, and
+// a refund that fires twice is a free heal.
+
+// castingCleric turns an existing sheet into a cleric who knows and has prepared
+// Cure Wounds, with slots to spend.
+func castingCleric(t *testing.T, uid id.UserID) {
+	t.Helper()
+	c, err := LoadDnDCharacter(uid)
+	if err != nil || c == nil {
+		t.Fatalf("load %s: %v", uid, err)
+	}
+	c.Class = ClassCleric
+	c.Level = 5
+	c.WIS = 16
+	if err := SaveDnDCharacter(c); err != nil {
+		t.Fatal(err)
+	}
+	if err := setSpellSlotsForCharacter(c); err != nil {
+		t.Fatal(err)
+	}
+	if err := addKnownSpell(uid, "cure_wounds", "class", true); err != nil {
+		t.Fatal(err)
+	}
+	if err := setSpellPrepared(uid, "cure_wounds", true); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func slotsUsed(t *testing.T, uid id.UserID, level int) int {
+	t.Helper()
+	slots, err := getSpellSlots(uid)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return slots[level][1]
+}
+
+func setCharHP(t *testing.T, uid id.UserID, hp int) {
+	t.Helper()
+	c, err := LoadDnDCharacter(uid)
+	if err != nil || c == nil {
+		t.Fatalf("load %s: %v", uid, err)
+	}
+	c.HPCurrent = hp
+	if err := SaveDnDCharacter(c); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestCastAlly_OutOfCombat_HealsTheFriendAndSpendsOneSlot(t *testing.T) {
+	setupEmptyTestDB(t)
+	leader, member := seatedMember(t, "e2eheal")
+	castingCleric(t, leader)
+	setCharHP(t, member, 5) // of 20
+
+	p := &AdventurePlugin{}
+	if err := p.handleDnDCastCmd(MessageContext{Sender: leader}, "cure wounds @"+member.Localpart()); err != nil {
+		t.Fatalf("cast: %v", err)
+	}
+
+	mc, _ := LoadDnDCharacter(member)
+	if mc.HPCurrent <= 5 {
+		t.Fatalf("the friend is still on %d HP; the heal landed on nobody", mc.HPCurrent)
+	}
+	// The caster must NOT have healed themselves — the bug this whole section exists for.
+	if lc, _ := LoadDnDCharacter(leader); lc.HPCurrent != lc.HPMax {
+		t.Fatalf("caster HP moved to %d/%d; the heal landed on the caster", lc.HPCurrent, lc.HPMax)
+	}
+	if used := slotsUsed(t, leader, 1); used != 1 {
+		t.Fatalf("level-1 slots used = %d, want exactly 1", used)
+	}
+}
+
+// Naming a full-HP ally must cost nothing: the slot is debited before the target
+// is touched, so this is the refund path firing for real.
+func TestCastAlly_OutOfCombat_FullHPAllyRefundsTheSlot(t *testing.T) {
+	setupEmptyTestDB(t)
+	leader, member := seatedMember(t, "e2efull")
+	castingCleric(t, leader)
+
+	p := &AdventurePlugin{}
+	if err := p.handleDnDCastCmd(MessageContext{Sender: leader}, "cure wounds @"+member.Localpart()); err != nil {
+		t.Fatalf("cast: %v", err)
+	}
+	if used := slotsUsed(t, leader, 1); used != 0 {
+		t.Fatalf("level-1 slots used = %d after healing a full-HP ally; the slot was not refunded", used)
+	}
+}
+
+// A target nobody can reach is refused before anything is spent.
+func TestCastAlly_OutOfCombat_StrangerCostsNothing(t *testing.T) {
+	setupEmptyTestDB(t)
+	leader, _ := seatedMember(t, "e2estranger")
+	castingCleric(t, leader)
+
+	p := &AdventurePlugin{}
+	if err := p.handleDnDCastCmd(MessageContext{Sender: leader}, "cure wounds @nobody"); err != nil {
+		t.Fatalf("cast: %v", err)
+	}
+	if used := slotsUsed(t, leader, 1); used != 0 {
+		t.Fatalf("level-1 slots used = %d after naming a stranger; nothing should have been spent", used)
+	}
+}
+
+// A target on a spell that cannot use one is refused, rather than quietly
+// dropping the target and firing the spell at the caster — which is what the old
+// "accept and ignore" parse did.
+func TestCastAlly_OutOfCombat_TargetOnANonHealIsRefused(t *testing.T) {
+	setupEmptyTestDB(t)
+	leader, member := seatedMember(t, "e2enonheal")
+	castingCleric(t, leader)
+	if err := addKnownSpell(leader, "guiding_bolt", "class", true); err != nil {
+		t.Fatal(err)
+	}
+
+	p := &AdventurePlugin{}
+	if err := p.handleDnDCastCmd(MessageContext{Sender: leader}, "guiding bolt @"+member.Localpart()); err != nil {
+		t.Fatalf("cast: %v", err)
+	}
+	if used := slotsUsed(t, leader, 1); used != 0 {
+		t.Fatalf("level-1 slots used = %d; a targeted non-heal must be refused before it is paid for", used)
+	}
+	if lc, _ := LoadDnDCharacter(leader); lc.PendingCast != "" {
+		t.Fatalf("guiding bolt queued as %q; the target should have refused the cast outright", lc.PendingCast)
+	}
+}

internal/plugin/dnd_cast_target.go

@@ -0,0 +1,156 @@
+package plugin
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"strings"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// Out-of-combat ally targeting for `!cast` — the other half of §1.
+//
+// splitCastTarget (combat_cmd.go) resolves a target against the people *in the
+// fight*. Out of combat there is no fight, so the equivalent set is the people
+// on your expedition: the party is who you are standing next to. Healing a
+// stranger across the world is not a thing a cleric at camp can do, and scoping
+// it to the party keeps the two `!cast` paths answering the same question.
+//
+// Only heals may name somebody else. Everything else `!cast` can do out of
+// combat either resolves on the caster (UTILITY) or queues as a PendingCast for
+// **the caster's** next fight — an ally target on those would be silently
+// dropped, which is how `--target` came to be swallowed in the first place.
+
+// splitOutOfCombatTarget peels an ally target off a `!cast` argument, using the
+// same two spellings the combat path accepts: the `--target @alex` flag, and a
+// plain trailing `@alex`. The bare form requires the `@` here (unlike in combat,
+// where the roster disambiguates) so a trailing spell word is never mistaken for
+// a name.
+//
+// Returns (remainingArgs, name). name is empty when no target was named.
+func splitOutOfCombatTarget(args string) (string, string) {
+	fields := strings.Fields(args)
+	for i := 0; i < len(fields); i++ {
+		if !strings.EqualFold(fields[i], "--target") {
+			continue
+		}
+		if i+1 >= len(fields) {
+			return args, ""
+		}
+		name := strings.TrimPrefix(fields[i+1], "@")
+		fields = append(fields[:i], fields[i+2:]...)
+		return strings.Join(fields, " "), name
+	}
+	if len(fields) == 0 {
+		return args, ""
+	}
+	if last := fields[len(fields)-1]; strings.HasPrefix(last, "@") {
+		if name := strings.TrimPrefix(last, "@"); name != "" {
+			return strings.Join(fields[:len(fields)-1], " "), name
+		}
+	}
+	return args, ""
+}
+
+// resolveCastTargetOnExpedition maps a named target to a human on the caster's
+// active expedition. errMsg is non-empty and player-facing on any failure; a
+// caster who names somebody must never fall through to healing themselves,
+// because that quietly burns the slot on the wrong body.
+func resolveCastTargetOnExpedition(caster id.UserID, name string) (id.UserID, string) {
+	exp, _, err := activeExpeditionFor(caster)
+	if err != nil {
+		return "", "Couldn't look up your expedition."
+	}
+	if exp == nil {
+		return "", "You're not travelling with anyone. `!cast` on yourself, or join a party first."
+	}
+	seats, err := partyHumans(exp.ID, exp.UserID)
+	if err != nil {
+		return "", "Couldn't look up your party."
+	}
+	for _, s := range seats {
+		uid := string(s.UserID)
+		if strings.EqualFold(uid, name) || strings.EqualFold(id.UserID(uid).Localpart(), name) {
+			if s.UserID == caster {
+				// Naming yourself is just casting it on yourself.
+				return "", ""
+			}
+			return s.UserID, ""
+		}
+		// Character name, which is what players actually call each other.
+		if n := charName(s.UserID); n != "" && strings.EqualFold(n, name) {
+			if s.UserID == caster {
+				return "", ""
+			}
+			return s.UserID, ""
+		}
+	}
+	if strings.EqualFold(name, companionDisplayName) {
+		return "", companionDisplayName + " patches himself up at camp. Save the slot."
+	}
+	return "", fmt.Sprintf("**%s** isn't on your expedition. You can only heal someone you're travelling with.", name)
+}
+
+// errHealTargetFull / errHealTargetDown are the two ways an ally heal declines
+// to spend the slot. Both are recoverable: the caller refunds.
+var (
+	errHealTargetFull = errors.New("target already at full HP")
+	errHealTargetDown = errors.New("target is down")
+)
+
+// healPartyMember applies a heal to somebody else's sheet.
+//
+// It does NOT take the target's advUserLock. Gifting sets the precedent
+// (adventure_gifting.go): mutate the other player's row with one guarded
+// statement rather than a read-modify-write under two locks. Two clerics healing
+// each other at the same instant would otherwise take those locks in opposite
+// orders and deadlock the pair of them.
+//
+// The clamp lives in SQL for the same reason — read, add, cap and write are one
+// statement, so a heal landing between a concurrent heal's read and write cannot
+// push anybody past their maximum.
+func healPartyMember(target id.UserID, amount int) (before, after, maxHP int, err error) {
+	tx, err := db.Get().Begin()
+	if err != nil {
+		return 0, 0, 0, err
+	}
+	defer func() { _ = tx.Rollback() }()
+
+	err = tx.QueryRow(
+		`SELECT hp_current, hp_max FROM dnd_character WHERE user_id = ?`,
+		string(target)).Scan(&before, &maxHP)
+	if errors.Is(err, sql.ErrNoRows) {
+		return 0, 0, 0, sql.ErrNoRows
+	}
+	if err != nil {
+		return 0, 0, 0, err
+	}
+	switch {
+	case before <= 0:
+		// A heal is not a resurrection — the same rule the combat path holds.
+		return before, before, maxHP, errHealTargetDown
+	case before >= maxHP:
+		return before, before, maxHP, errHealTargetFull
+	}
+
+	if _, err = tx.Exec(
+		`UPDATE dnd_character
+		    SET hp_current = MIN(hp_max, hp_current + ?),
+		        updated_at = CURRENT_TIMESTAMP
+		  WHERE user_id = ? AND hp_current > 0`,
+		amount, string(target)); err != nil {
+		return before, before, maxHP, err
+	}
+	if err = tx.QueryRow(
+		`SELECT hp_current FROM dnd_character WHERE user_id = ?`,
+		string(target)).Scan(&after); err != nil {
+		return before, before, maxHP, err
+	}
+	if err = tx.Commit(); err != nil {
+		return before, before, maxHP, err
+	}
+	return before, after, maxHP, nil
+}

internal/plugin/dnd_cast_target_test.go

@@ -0,0 +1,102 @@
+package plugin
+
+import (
+	"errors"
+	"testing"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// The out-of-combat half of §1. `--target` was parsed and thrown away here since
+// SP2 ("reserved for SP3, accept and ignore"), so a party cleric standing over a
+// bleeding friend between fights could do precisely nothing for them.
+
+func TestSplitOutOfCombatTarget(t *testing.T) {
+	cases := []struct {
+		name, args, wantRest, wantTarget string
+	}{
+		{"flag", "cure wounds --target @alex", "cure wounds", "alex"},
+		{"flag mid-string", "cure wounds --target @alex --upcast 3", "cure wounds --upcast 3", "alex"},
+		{"flag without the @", "cure wounds --target alex", "cure wounds", "alex"},
+		{"trailing mention", "cure wounds @alex", "cure wounds", "alex"},
+		{"no target", "cure wounds", "cure wounds", ""},
+		// A trailing bare word is a spell word, not a name — the `@` is what makes
+		// it a target out of combat. Getting this wrong eats half of "cure wounds".
+		{"bare trailing word is not a target", "healing word", "healing word", ""},
+		{"upcast digit is not a target", "cure wounds --upcast 3", "cure wounds --upcast 3", ""},
+		{"dangling flag", "cure wounds --target", "cure wounds --target", ""},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			rest, target := splitOutOfCombatTarget(tc.args)
+			if rest != tc.wantRest || target != tc.wantTarget {
+				t.Fatalf("splitOutOfCombatTarget(%q) = (%q, %q), want (%q, %q)",
+					tc.args, rest, target, tc.wantRest, tc.wantTarget)
+			}
+		})
+	}
+}
+
+// The target set is the expedition, not the world: you can heal the person you
+// are travelling with, and nobody else.
+func TestResolveCastTarget_OnlyThePartyIsReachable(t *testing.T) {
+	setupEmptyTestDB(t)
+	leader, member := seatedMember(t, "casttarget")
+
+	uid, errMsg := resolveCastTargetOnExpedition(leader, member.Localpart())
+	if errMsg != "" || uid != member {
+		t.Fatalf("leader → member = (%q, %q); want the member, no error", uid, errMsg)
+	}
+
+	// Somebody with a sheet, but not on this expedition.
+	stranger := id.UserID("@stranger-casttarget:example.org")
+	zoneCmdTestCharacter(t, stranger, 1)
+	if _, errMsg := resolveCastTargetOnExpedition(leader, stranger.Localpart()); errMsg == "" {
+		t.Fatal("healed a stranger across the world; only the party is reachable")
+	}
+
+	// Naming yourself is just casting it on yourself: no target, no error. A
+	// refusal here would make `!cast cure wounds @me` cost a slot for nothing.
+	if uid, errMsg := resolveCastTargetOnExpedition(leader, leader.Localpart()); uid != "" || errMsg != "" {
+		t.Fatalf("self-target = (%q, %q); want the self-heal path, silently", uid, errMsg)
+	}
+}
+
+func TestHealPartyMember_ClampsAtMaxAndWillNotRaiseTheDead(t *testing.T) {
+	setupEmptyTestDB(t)
+	target := id.UserID("@heal-target:example.org")
+	zoneCmdTestCharacter(t, target, 1) // HPMax 20
+
+	setHP := func(hp int) {
+		c, err := LoadDnDCharacter(target)
+		if err != nil || c == nil {
+			t.Fatalf("load: %v", err)
+		}
+		c.HPCurrent = hp
+		if err := SaveDnDCharacter(c); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	// A heal bigger than the wound tops out at max rather than overflowing.
+	setHP(15)
+	before, after, maxHP, err := healPartyMember(target, 100)
+	if err != nil || before != 15 || after != 20 || maxHP != 20 {
+		t.Fatalf("overheal = (%d → %d / %d, %v); want clamped to 20", before, after, maxHP, err)
+	}
+
+	// Already full: decline so the caller can refund. Spending a slot to heal
+	// zero HP is the kind of thing players never forgive.
+	if _, _, _, err := healPartyMember(target, 10); !errors.Is(err, errHealTargetFull) {
+		t.Fatalf("healing a full-HP ally = %v; want errHealTargetFull", err)
+	}
+
+	// Down: a heal is not a resurrection. Same rule the combat path holds.
+	setHP(0)
+	if _, _, _, err := healPartyMember(target, 10); !errors.Is(err, errHealTargetDown) {
+		t.Fatalf("healing a downed ally = %v; want errHealTargetDown", err)
+	}
+	if c, _ := LoadDnDCharacter(target); c == nil || c.HPCurrent != 0 {
+		t.Fatal("the downed ally was raised by a heal")
+	}
+}

internal/plugin/dnd_combat.go

@@ -605,3 +605,51 @@ func emitDeathNews(userID id.UserID, location string) {
 		OccurredAt: ts,
 	}, userID, "")
 }
+
+// emitRetreatNews files a BULLETIN when an expedition ends with the player
+// walking out alive.
+//
+// Until this existed the news had no way to say "it went badly but nobody
+// died", so it never said it. Pete's whole taxonomy was arrival, companion_hire,
+// death, milestone, rival_result and zone_first — every one of them a win, a
+// death, or an introduction. A run that simply fell apart emitted nothing, and
+// the feed showed a realm where adventurers only ever triumph or die.
+//
+// That was not a rare gap. Before §6, a cleric retreated on 167 of 500
+// simulated expeditions: a third of that class's runs ended in a way the news
+// was structurally incapable of reporting. Casters did not look unlucky in the
+// feed — they looked absent.
+//
+// Bulletin, not priority: a retreat is a bad day, not a funeral. A death already
+// files its own priority dispatch from markAdventureDead, and a wipe that killed
+// someone must not ALSO be reported as a retreat — hence the reason gate rather
+// than an "expedition ended" catch-all. An idle reap is excluded too: a player
+// who closed their laptop did not flee anything, and Pete announcing that they
+// were driven from the field would be a lie about a person by name.
+func emitRetreatNews(userID id.UserID, reason string, zoneID ZoneID, day int) {
+	switch reason {
+	case lossCombatRetreat, lossCombatFlee:
+	default:
+		return // a death tells its own story; an idle reap is not a story
+	}
+	if !peteclient.Enabled() || !newsEmissionOn() {
+		return
+	}
+	name := charName(userID)
+	if name == "" {
+		return
+	}
+	zone := zoneOrFallback(zoneID)
+	ts := nowUnix()
+	emitFact(peteclient.Fact{
+		GUID:       fmt.Sprintf("retreat:%s:%d", eventToken(userID, fmt.Sprintf("%d", ts)), ts),
+		EventType:  "retreat",
+		Tier:       "bulletin",
+		Subject:    name,
+		Zone:       zone.Display,
+		Level:      charLevel(userID),
+		Count:      day, // the day they got to before it fell apart
+		Outcome:    "retreated",
+		OccurredAt: ts,
+	}, userID, "")
+}

internal/plugin/dnd_expedition_camp.go

@@ -325,6 +325,13 @@ func applyCampRest(e *Expedition, kind string) string {
 	if kind == CampTypeStandard || kind == CampTypeFortified || kind == CampTypeBase {
 		_ = refreshAllResources(uid)
 		_ = refreshSpellSlots(uid)
+		// The companion sleeps at the same fire. His slots and his wounds are not
+		// dnd_spell_slots / dnd_character rows — he has none — so nothing above
+		// reaches him, and without these two his pool and his body would only ever
+		// go down. Camp is where a caster gets their slots back and a body gets
+		// patched up, and he is at the camp.
+		_ = refreshCompanionSlots(e.ID)
+		_ = refreshCompanionHP(e.ID)
 		_ = ReplenishHarvestNodes(e)
 	}
 

internal/plugin/dnd_expedition_cmd.go

@@ -95,6 +95,10 @@ func (p *AdventurePlugin) handleDnDExpeditionCmd(ctx MessageContext, args string
 		return p.expeditionCmdParty(ctx)
 	case "leave":
 		return p.expeditionCmdLeave(ctx)
+	case "hire":
+		return p.expeditionCmdHire(ctx, rest)
+	case "dismiss":
+		return p.expeditionCmdDismiss(ctx)
 	case "extract":
 		return p.handleExtractCmd(ctx, "")
 	case "resume":
@@ -122,7 +126,9 @@ func expeditionHelpText() string {
 	b.WriteString("`!expedition invite @user` — they buy their own supplies into the party pool\n")
 	b.WriteString("`!expedition accept` / `!expedition decline` — answer an invite\n")
 	b.WriteString("`!expedition party` — who's with you\n")
-	b.WriteString("`!expedition leave` — turn back for town (members only)\n\n")
+	b.WriteString("`!expedition leave` — turn back for town (members only)\n")
+	b.WriteString("`!expedition hire [class]` — pay Pete to fill the role you're missing\n")
+	b.WriteString("`!expedition dismiss` — send Pete home\n\n")
 	b.WriteString("**Mid-expedition:**\n")
 	b.WriteString("`!extract` — bail safely (resumable for 7 days)\n")
 	b.WriteString("`!resume [loadout]` — resume an extracted expedition\n")

internal/plugin/dnd_expedition_extract.go

@@ -95,21 +95,40 @@ func forcedExtractExpedition(expID, reason string) (*Expedition, int, error) {
 	return e, tax, nil
 }
 
+// The reasons a run can end badly. They were bare strings at four call sites;
+// they are constants now because the news seam has to tell them apart — a
+// retreat is a story and a death is a different story, and an idle reap is
+// neither.
+const (
+	lossCombatDeath   = "combat death"
+	lossCombatRetreat = "combat retreat" // solo: ran out the phase clock and withdrew
+	lossCombatFlee    = "combat flee"    // party: the turn engine broke off
+	lossIdleTimeout   = "run idle-timeout (§4.3 stale-run reap)"
+)
+
 // forceExtractExpeditionForRunLoss bridges run-loss call sites (turn-based
 // elite/boss death or flee, exploration combat death, patrol-interrupt
 // death) into the forced-extract flow. Those sites already abandon the
 // zone run, but without flipping the wrapping expedition the ambient
 // ticker keeps DMing about a dungeon the player walked away from. No-op
 // when there is no active expedition for this user.
+//
+// It is also the one chokepoint every bad ending passes through, which makes it
+// where the retreat dispatch is filed. Read the expedition BEFORE the extract:
+// forcedExtractExpedition stamps it 'abandoned' and zeroes the live fields, so
+// afterwards there is no day count left to report.
 func forceExtractExpeditionForRunLoss(userID id.UserID, reason string) {
 	exp, err := getActiveExpedition(userID)
 	if err != nil || exp == nil {
 		return
 	}
+	day, zoneID := exp.CurrentDay, exp.ZoneID
 	if _, _, err := forcedExtractExpedition(exp.ID, reason); err != nil {
 		slog.Warn("expedition: force-extract on run loss",
 			"user", userID, "expedition", exp.ID, "reason", reason, "err", err)
+		return
 	}
+	emitRetreatNews(userID, reason, zoneID, day)
 }
 
 // finalizeExpeditionOnZoneClear bridges the run-complete seam (boss down,

internal/plugin/dnd_zone_cmd.go

@@ -1207,9 +1207,9 @@ func (p *AdventurePlugin) resolveCombatRoom(userID id.UserID, run *DungeonRun, z
 		// seat off HP, which for a solo walker is the same `!TimedOut` rule.
 		closeOutZoneLoss(pres, seated, zone, "zone")
 		if !result.TimedOut {
-			forceExtractExpeditionForRunLoss(userID, "combat death")
+			forceExtractExpeditionForRunLoss(userID, lossCombatDeath)
 		} else {
-			forceExtractExpeditionForRunLoss(userID, "combat retreat")
+			forceExtractExpeditionForRunLoss(userID, lossCombatRetreat)
 		}
 		if line := twinBeeLine(zone.ID, DMPlayerDeath, run.RunID, narrationCadence(run)); line != "" {
 			ob.WriteString(line)

internal/plugin/dnd_zone_run.go

@@ -323,7 +323,7 @@ func getActiveZoneRun(userID id.UserID) (*DungeonRun, error) {
 		// but only when this run is the active expedition's current run so
 		// a standalone (non-expedition) stale run still reaps cleanly.
 		if exp, _ := getActiveExpedition(userID); exp != nil && exp.RunID == r.RunID {
-			forceExtractExpeditionForRunLoss(userID, "run idle-timeout (§4.3 stale-run reap)")
+			forceExtractExpeditionForRunLoss(userID, lossIdleTimeout)
 		}
 		return nil, nil
 	}

internal/plugin/expedition_companion_cmd.go

@@ -0,0 +1,115 @@
+package plugin
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// The player-facing surface for hiring Pete.
+//
+//	!expedition hire [class]   (leader, Day 1 — auto-fills the missing role)
+//	!expedition dismiss        (leader — sends him home, no refund)
+//
+// He is hired on Day 1 like any other companion, because a body that materializes
+// three rooms in is not a party member, it is a cheat code. See
+// adventure_companion.go for why he is an NPC seat and not a player.
+
+// expeditionCmdHire brings the correspondent along.
+func (p *AdventurePlugin) expeditionCmdHire(ctx MessageContext, rest string) error {
+	exp, isLeader, err := activeExpeditionFor(ctx.Sender)
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't read expedition state: "+err.Error())
+	}
+	if exp == nil {
+		return p.SendDM(ctx.Sender, "No active expedition. `!expedition start <zone>` first.")
+	}
+	if !isLeader {
+		return p.SendDM(ctx.Sender, "Only the party leader hires. You're along for the ride.")
+	}
+	if !inviteWindowOpen(exp) {
+		return p.SendDM(ctx.Sender,
+			"This expedition has already set off — Pete joins on Day 1 or not at all.")
+	}
+	if companionSeated(exp.ID) {
+		return p.SendDM(ctx.Sender, "Pete's already with you. `!expedition party` to see the roster.")
+	}
+	if p.euro == nil {
+		return p.SendDM(ctx.Sender, "Coin system unavailable — try again later.")
+	}
+
+	zone := zoneOrFallback(exp.ZoneID)
+	level := companionPartyLevel(exp.ID)
+
+	class, explicit := parseCompanionClass(rest)
+	if !explicit {
+		if arg := strings.TrimSpace(rest); arg != "" && !strings.EqualFold(arg, "auto") {
+			return p.SendDM(ctx.Sender, fmt.Sprintf(
+				"Don't know the class %q. Name one, or just `!expedition hire` and he'll fill whatever you're missing.", arg))
+		}
+		class = companionRoleFill(companionPartyClasses(exp.ID))
+	}
+
+	cost := float64(companionHireCost(level, zone.Tier))
+	if balance := p.euro.GetBalance(ctx.Sender); balance < cost {
+		return p.SendDM(ctx.Sender, fmt.Sprintf(
+			"Pete doesn't work for free. His fee for **%s** is **%d** — you have **%.0f**.",
+			zone.Display, int(cost), balance))
+	}
+	if !p.euro.Debit(ctx.Sender, cost, "expedition: hired Pete") {
+		return p.SendDM(ctx.Sender, "Couldn't debit Pete's fee (try again).")
+	}
+
+	if err := hireCompanion(exp.ID, class, level); err != nil {
+		p.euro.Credit(ctx.Sender, cost, "expedition: Pete hire refund")
+		return p.SendDM(ctx.Sender, companionRefusalText(err))
+	}
+
+	emitCompanionHireFact(ctx.Sender, class, level, zone)
+
+	ci, _ := classInfo(class)
+	filled := "You asked for a " + ci.Display + "."
+	if !explicit {
+		filled = "He's filling the hole in your roster — **" + ci.Display + "**."
+	}
+	return p.SendDM(ctx.Sender, fmt.Sprintf(
+		"📝 **Pete's coming with you into %s.** %s He's **level %d**, and his fee was **%d**.\n\n"+
+			"He fights his own turns — you don't command him. He takes no loot and no XP; he's here for the story.\n"+
+			"`!expedition dismiss` sends him home (no refund — he's already packed).",
+		zone.Display, filled, level, int(cost)))
+}
+
+// expeditionCmdDismiss sends him home mid-run.
+func (p *AdventurePlugin) expeditionCmdDismiss(ctx MessageContext) error {
+	exp, isLeader, err := activeExpeditionFor(ctx.Sender)
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't read expedition state: "+err.Error())
+	}
+	if exp == nil {
+		return p.SendDM(ctx.Sender, "No active expedition.")
+	}
+	if !isLeader {
+		return p.SendDM(ctx.Sender, "Only the party leader can dismiss him.")
+	}
+	if err := dismissCompanion(exp.ID); err != nil {
+		return p.SendDM(ctx.Sender, companionRefusalText(err))
+	}
+	return p.SendDM(ctx.Sender,
+		"📝 **Pete heads back.** He got what he came for. The fee stays spent.")
+}
+
+// companionRefusalText turns the companion layer's sentinel errors into copy.
+func companionRefusalText(err error) string {
+	switch {
+	case errors.Is(err, ErrCompanionAlreadyHired):
+		return "Pete's already with you."
+	case errors.Is(err, ErrCompanionOnAssignment):
+		return "Pete's out on assignment with another party. He'll be back."
+	case errors.Is(err, ErrCompanionNotHired):
+		return "Pete isn't with you."
+	case errors.Is(err, ErrPartyFull):
+		return "No room — your party's full. Someone has to `!expedition leave` first."
+	default:
+		return "Couldn't hire Pete: " + err.Error()
+	}
+}

internal/plugin/expedition_party.go

@@ -82,30 +82,126 @@ func partyMembers(expeditionID string) ([]PartyMember, error) {
 	return out, rows.Err()
 }
 
-// partyMemberIDs is partyMembers reduced to user ids, leader first. It is what
+// PartySeatKind is what a seat *is*. The three answers differ in ways that matter
-// the fan-out seams (digest, briefing, recap) want: a solo expedition yields
+// at almost every seam, and conflating any two of them has already cost us a bug:
-// just the owner, so a caller can loop unconditionally.
+// a companion is a seat but not a mouth and not a mailbox; a leader owns the
-func partyMemberIDs(expeditionID, ownerID string) ([]id.UserID, error) {
+// expedition row that everyone else references.
-	members, err := partyMembers(expeditionID)
+type PartySeatKind int
+
+const (
+	SeatLeader PartySeatKind = iota
+	SeatMember
+	SeatCompanion
+)
+
+// PartySeat is one body on an expedition.
+type PartySeat struct {
+	UserID id.UserID
+	Kind   PartySeatKind
+}
+
+// IsHuman reports whether there is a person behind this seat — someone who can be
+// DM'd, can earn loot, eats supplies, and can die.
+func (s PartySeat) IsHuman() bool { return s.Kind != SeatCompanion }
+
+// expeditionParty is THE answer to "who is on this expedition". Every other view
+// — who gets mail, who sits down in a fight, who eats — is derived from it.
+//
+// It ALWAYS includes the owner. That is the whole point, and it is not a
+// convenience: a solo expedition has **no expedition_party rows at all** (the
+// roster only materializes on the first invite — see partyMembers), so any code
+// that answers "who is in this party?" by reading the roster table gets *nobody*
+// for a solo player, and then quietly falls back to whatever looked sensible at
+// the call site.
+//
+// That is not hypothetical. It is exactly how the hired companion came out at
+// **level 1** for every solo player — the one player the feature exists for. The
+// level was averaged over the party; the party read as empty; the fallback was 1.
+// He then walked into a tier-4 zone as a level-1 body, died on contact, and left
+// the leader fighting a boss that had been inflated on his account. A 1500-run
+// sweep is what found it, because nothing else could.
+//
+// So: there is no way to ask this function for the party and be handed an empty
+// list. If the expedition exists, it has at least a leader.
+func expeditionParty(expeditionID, ownerID string) ([]PartySeat, error) {
+	rows, err := partyMembers(expeditionID)
 	if err != nil {
 		return nil, err
 	}
-	if len(members) == 0 {
+	if len(rows) == 0 {
-		return []id.UserID{id.UserID(ownerID)}, nil
+		// Solo: no roster rows. The owner IS the party.
+		if ownerID == "" {
+			return nil, nil
 		}
-	out := make([]id.UserID, 0, len(members))
+		return []PartySeat{{UserID: id.UserID(ownerID), Kind: SeatLeader}}, nil
-	for _, m := range members {
+	}
-		out = append(out, id.UserID(m.UserID))
+	out := make([]PartySeat, 0, len(rows))
+	for _, m := range rows {
+		kind := SeatMember
+		switch {
+		case isCompanionUser(m.UserID):
+			kind = SeatCompanion
+		case m.IsLeader():
+			kind = SeatLeader
+		}
+		out = append(out, PartySeat{UserID: id.UserID(m.UserID), Kind: kind})
 	}
 	return out, nil
 }
 
-// partySize is the number of seated players: 1 for a solo expedition.
+// partyHumans is the party minus the companion: everyone with a person behind
+// them. This is the set that gets mail, earns loot, eats supplies, and can die.
+func partyHumans(expeditionID, ownerID string) ([]PartySeat, error) {
+	seats, err := expeditionParty(expeditionID, ownerID)
+	if err != nil {
+		return nil, err
+	}
+	out := seats[:0]
+	for _, s := range seats {
+		if s.IsHuman() {
+			out = append(out, s)
+		}
+	}
+	return out, nil
+}
+
+// partyMemberIDs is the whole party as ids, leader first — every body, companion
+// included. Callers that want only people want partyHumans.
+func partyMemberIDs(expeditionID, ownerID string) ([]id.UserID, error) {
+	seats, err := expeditionParty(expeditionID, ownerID)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]id.UserID, 0, len(seats))
+	for _, s := range seats {
+		out = append(out, s.UserID)
+	}
+	return out, nil
+}
+
+// partySize is the number of seated *players*: 1 for a solo expedition.
+//
+// A hired companion is not counted, and both of this function's consumers want
+// it that way:
+//
+//   - expeditionBurnRatePct scales the daily supply burn by party size. Pete
+//     never bought a pack — members buy their own on !expedition accept, and he
+//     accepts nothing — so counting him would bill the leader a 60% higher burn
+//     for a mouth that brought its own rations. He is on expenses.
+//   - the "your party is still waiting on you" gate blocks a leader from
+//     starting a new run while an extracted party is pending. A roster holding
+//     nobody but Pete is not a party waiting on anyone, and counting him would
+//     lock the leader out of the game until they abandoned the run.
+//
+// The combat roster is a different question with a different answer: Pete IS a
+// body in the fight, so CombatSession.RosterSize() counts him and the enemy-HP
+// scalar feels him. Seats and mouths are not the same set.
 func partySize(expeditionID string) (int, error) {
 	var n int
 	err := db.Get().QueryRow(
-		`SELECT COUNT(*) FROM expedition_party WHERE expedition_id = ?`,
+		`SELECT COUNT(*) FROM expedition_party
-		expeditionID).Scan(&n)
+		  WHERE expedition_id = ? AND user_id <> ?`,
+		expeditionID, string(companionUserID())).Scan(&n)
 	if err != nil {
 		return 0, err
 	}

internal/plugin/expedition_party_cmd.go

@@ -246,6 +246,10 @@ func (p *AdventurePlugin) expeditionCmdParty(ctx MessageContext) error {
 		b.WriteString(fmt.Sprintf("**%s** — alone.\n", p.DisplayName(id.UserID(exp.UserID))))
 	}
 	for _, m := range members {
+		if isCompanionUser(m.UserID) {
+			b.WriteString(companionRosterLine(exp.ID))
+			continue
+		}
 		role := "member"
 		if m.IsLeader() {
 			role = "leader"
@@ -260,6 +264,9 @@ func (p *AdventurePlugin) expeditionCmdParty(ctx MessageContext) error {
 	b.WriteString(fmt.Sprintf("\nSupplies: **%.1f / %.1f SU**", exp.Supplies.Current, exp.Supplies.Max))
 	if inviteWindowOpen(exp) {
 		b.WriteString("\n\n_`!expedition invite @user` while it's still Day 1._")
+		if !companionSeated(exp.ID) {
+			b.WriteString("\n_Short a body? `!expedition hire` brings Pete along._")
+		}
 	}
 	return p.SendDM(ctx.Sender, b.String())
 }

internal/plugin/expedition_party_resolve.go

@@ -108,13 +108,45 @@ func seatedExpeditionFor(userID id.UserID) (*Expedition, error) {
 // degrades to the owner rather than dropping the message — a player who misses
 // their briefing because SQLite hiccuped is a worse outcome than a member who
 // misses theirs.
+//
+// A hired companion is dropped here, and this is the chokepoint that keeps him
+// out of every DM seam at once: the briefing, the recap, the digest, the
+// extraction notice — and, crucially, the per-member side effects that ride the
+// fan-out rather than the message. maybeRollPetArrivalOnEmerge would offer Pete
+// a pet and park a pending interaction awaiting a reply that never comes;
+// maybeFireAnchoredEvent would claim him a daily event slot and DM him a
+// choice. He is not a person; he does not get mail. See isCompanionSeat.
 func expeditionAudience(e *Expedition) []id.UserID {
+	if e == nil || e.UserID == "" {
+		return nil
+	}
+	seats, err := partyHumans(e.ID, e.UserID)
+	if err != nil {
+		slog.Warn("expedition: party roster read failed, DMing owner only",
+			"expedition", e.ID, "err", err)
+		return []id.UserID{id.UserID(e.UserID)}
+	}
+	out := make([]id.UserID, 0, len(seats))
+	for _, s := range seats {
+		out = append(out, s.UserID)
+	}
+	return out
+}
+
+// expeditionSeats is every body that sits down in a fight: the whole roster,
+// hired companion included. It is deliberately NOT expeditionAudience — that one
+// drops the companion because he does not get mail, and a combat roster built
+// from it would seat everyone the leader paid for except the one he paid for.
+//
+// Mail and seats are different sets. Anything that sends is an audience;
+// anything that fights is a seat.
+func expeditionSeats(e *Expedition) []id.UserID {
 	if e == nil || e.UserID == "" {
 		return nil
 	}
 	ids, err := partyMemberIDs(e.ID, e.UserID)
 	if err != nil {
-		slog.Warn("expedition: party roster read failed, DMing owner only",
+		slog.Warn("expedition: party roster read failed, seating owner only",
 			"expedition", e.ID, "err", err)
 		return []id.UserID{id.UserID(e.UserID)}
 	}

internal/plugin/expedition_sim.go

@@ -34,6 +34,11 @@ func simInlineBossCombat() bool { return os.Getenv("GOGOBEE_SIM_INLINE_BOSS") ==
 type SimRunner struct {
 	P    *AdventurePlugin
 	Euro *EuroPlugin
+	// Companion hires Pete into the party on Day 1: "" = none, "auto" = fill the
+	// missing role, or an explicit class id. He takes a combat seat and no loot,
+	// which is exactly the thing the sweep is here to measure — whether an extra
+	// below-median body lifts the trailing case without carrying it.
+	Companion string
 }
 
 // NewSimRunner initializes a fresh sqlite DB in dataDir and constructs
@@ -400,7 +405,42 @@ type SimCombatSummary struct {
 	// SetSimIncludeTrace(true) has been called, and only on the LAST
 	// combat per expedition (the boss room) to keep JSONL size bounded.
 	// Used by J2 caster-survival analysis.
-	Events []CombatEvent `json:",omitempty"`
+	Events []simTraceEvent `json:",omitempty"`
+}
+
+// simTraceEvent is CombatEvent with the seat ALWAYS emitted.
+//
+// CombatEvent.Seat is `omitempty` for wire-compat reasons that are correct for
+// persistence and wrong for a trace: seat 0 and "no seat" serialize identically,
+// so a party trace silently reads as a solo fight. That is not hypothetical — it
+// is what made a hired companion who never took a turn look, in the JSON, like a
+// fight that only ever had one seat, and it cost an hour of chasing the wrong bug.
+// A diagnostic that cannot tell you who acted is not a diagnostic.
+type simTraceEvent struct {
+	Round       int
+	Seat        int // always present, even when 0
+	Phase       string
+	Actor       string
+	Action      string
+	Damage      int
+	PlayerHP    int
+	EnemyHP     int
+	Roll        int
+	RollAgainst int
+	Desc        string `json:",omitempty"`
+}
+
+// simTraceEvents converts a TurnLog for the trace.
+func simTraceEvents(events []CombatEvent) []simTraceEvent {
+	out := make([]simTraceEvent, len(events))
+	for i, e := range events {
+		out[i] = simTraceEvent{
+			Round: e.Round, Seat: e.Seat, Phase: e.Phase, Actor: e.Actor, Action: e.Action,
+			Damage: e.Damage, PlayerHP: e.PlayerHP, EnemyHP: e.EnemyHP,
+			Roll: e.Roll, RollAgainst: e.RollAgainst, Desc: e.Desc,
+		}
+	}
+	return out
 }
 
 // simIncludeTrace gates per-round event capture on SimCombatSummary.
@@ -516,6 +556,22 @@ func (s *SimRunner) RunPartyExpedition(uid id.UserID, members []id.UserID, zoneI
 			return res, fmt.Errorf("expedition vanished while seating the party")
 		}
 	}
+	// Hire the companion on Day 1, after the humans are seated so the role fill
+	// sees the party it is filling a hole in. He is not in `members` — he buys no
+	// packs and takes no seat in the human roster — but fightRoster reads
+	// expeditionSeats, so he shows up in every fight from here on.
+	if s.Companion != "" {
+		class, ok := parseCompanionClass(s.Companion)
+		if !ok {
+			class = companionRoleFill(companionPartyClasses(exp.ID))
+		}
+		if err := hireCompanion(exp.ID, class, companionPartyLevel(exp.ID)); err != nil {
+			res.Outcome = "halted"
+			res.StopCode = "companion:" + err.Error()
+			return res, err
+		}
+	}
+
 	roster := append([]id.UserID{uid}, members...)
 	res.PartySize = len(roster)
 	for _, m := range members {
@@ -942,7 +998,7 @@ func simCombatSummaries(uid id.UserID) []SimCombatSummary {
 		out = append(out, s)
 	}
 	if simIncludeTrace && len(out) > 0 {
-		out[len(out)-1].Events = lastEvents
+		out[len(out)-1].Events = simTraceEvents(lastEvents)
 	}
 	return out
 }
@@ -1038,6 +1094,18 @@ func (p *AdventurePlugin) autoDriveCombat(ctx MessageContext) (bool, error) {
 			turn.Sender = id.UserID(cur.seatUserID(seat))
 		}
 
+		// An engine-driven seat is never dispatched as a chat command. There is no
+		// character for the handlers to load, and a command arriving from that
+		// seat's id reads to beginCombatTurn as a player returning to the keyboard
+		// — which is how the driver used to clear the very latch that was moving
+		// the seat. Drive it directly instead.
+		if cur.seatIsEngineDriven(seat) {
+			if err := p.driveEngineSeat(cur, seat); err != nil {
+				return false, fmt.Errorf("engine seat %d: %w", seat, err)
+			}
+			continue
+		}
+
 		kind, arg := p.pickAutoCombatActionForSeat(turn.Sender, cur, seat)
 		var dispatchErr error
 		switch kind {
@@ -1142,8 +1210,16 @@ func (p *AdventurePlugin) pickAutoCombatAction(uid id.UserID, sess *CombatSessio
 // which is seat 0. Driving a party member's turn off the leader's HP would heal
 // the wrong person and re-arm the wrong aura.
 func (p *AdventurePlugin) pickAutoCombatActionForSeat(uid id.UserID, sess *CombatSession, seat int) (kind, arg string) {
-	c, _ := LoadDnDCharacter(uid)
+	if sess == nil {
-	if c == nil || sess == nil {
+		return "attack", ""
+	}
+	// seatPickSheet, not LoadDnDCharacter: the hired companion has no character row
+	// and never will, so the raw load returned nil for him and this function bailed
+	// to "attack" on its first line — every turn, for the whole fight. That one line
+	// is why a hired Cleric swung a mace while the party died. He fights off the
+	// same synthetic sheet the rest of his seat is built from.
+	c := seatPickSheet(sess, uid)
+	if c == nil {
 		return "attack", ""
 	}
 	st := sess.actorStatusesForSeat(seat)
@@ -1157,6 +1233,20 @@ func (p *AdventurePlugin) pickAutoCombatActionForSeat(uid id.UserID, sess *Comba
 			}
 		}
 	}
+	// §1 — a healer with a hurt friend heals the friend. This is what a competent
+	// player does, and until the engine could target another seat it was not an
+	// option the picker even had. It runs before the damage picks: a party member
+	// about to die is a more urgent use of a slot than another Fireball.
+	// A healer heals whoever is worst off — the friend bleeding out beside them, or
+	// themselves. An empty target is a self-cast, and `!cast <spell>` with no
+	// @mention is exactly how a player writes that.
+	if id, target := simPickHeal(c, uid, sess, seat); id != "" {
+		if target == "" {
+			return "cast", id
+		}
+		return "cast", id + " @" + target
+	}
+
 	if isSpellcaster(c) && !simMartialFirstClass(c.Class) {
 		// Cleric: Spiritual Weapon is a BuffSelf that fires a spectral
 		// bonus-action attack each round via SpiritWeaponProc/Dmg mods —
@@ -1164,7 +1254,7 @@ func (p *AdventurePlugin) pickAutoCombatActionForSeat(uid id.UserID, sess *Comba
 		// otherwise never spends an L2 slot on it. Force the pick once
 		// per fight (BuffSpiritProc==0) so the picker doesn't pretend
 		// it's not a damage option.
-		if id := simPickSpiritualWeapon(c, uid, st); id != "" {
+		if id := simPickSpiritualWeapon(c, sess, seat, uid, st); id != "" {
 			return "cast", id
 		}
 		// Once a concentration aura is up, a competent caster maintains it and
@@ -1172,7 +1262,7 @@ func (p *AdventurePlugin) pickAutoCombatActionForSeat(uid id.UserID, sess *Comba
 		// slot to re-arm the same aura — so the picker excludes concentration
 		// spells while one is active.
 		auraActive := st.ConcentrationDmg > 0
-		if id := simPickSpell(c, uid, auraActive); id != "" {
+		if id := simPickSpell(c, sess, seat, uid, auraActive); id != "" {
 			return "cast", id
 		}
 	}
@@ -1207,14 +1297,14 @@ func simMartialFirstClass(class DnDClass) bool {
 // above 2nd, so spending a precious L5 to add a single d8 to the proc is
 // not worth burning the bigger slot's damage potential elsewhere; sim
 // behaves like a competent player and saves the high slot.
-func simPickSpiritualWeapon(c *DnDCharacter, uid id.UserID, st ActorStatuses) string {
+func simPickSpiritualWeapon(c *DnDCharacter, sess *CombatSession, seat int, uid id.UserID, st ActorStatuses) string {
 	if c == nil || c.Class != ClassCleric {
 		return ""
 	}
 	if st.BuffSpiritProc > 0 {
 		return ""
 	}
-	known, err := listKnownSpells(uid)
+	known, err := seatKnownSpells(sess, seat, uid)
 	if err != nil {
 		return ""
 	}
@@ -1228,7 +1318,7 @@ func simPickSpiritualWeapon(c *DnDCharacter, uid id.UserID, st ActorStatuses) st
 	if !prepared {
 		return ""
 	}
-	slots, _ := getSpellSlots(uid)
+	slots, _ := seatSpellSlots(sess, seat, uid)
 	const simMaxSlot = 5
 	for sl := 2; sl <= simMaxSlot; sl++ {
 		pair, ok := slots[sl]
@@ -1261,12 +1351,111 @@ func simPickSpiritualWeapon(c *DnDCharacter, uid id.UserID, st ActorStatuses) st
 //   - Among feasible candidates, prefer higher slot level (preserves
 //     high-slot supremacy and burns the big slots first); tie-break on
 //     expected damage from the dice string.
-func simPickSpell(c *DnDCharacter, uid id.UserID, auraActive bool) string {
+//
-	known, err := listKnownSpells(uid)
+// simHealAllyThresholdPct is how hurt a friend has to be before a healer spends a
+// slot on them rather than on damage. Deliberately lower than the self-heal
+// threshold: a heal is a wasted turn if the target was going to live anyway, and
+// the party's damage output is what ends the fight.
+const simHealAllyThresholdPct = 45
+
+// simPickHeal returns the heal spell a competent healer would cast this turn, and
+// the seat to put it on — which may be the healer's own. An empty spell id means
+// nobody needs healing, or this character cannot heal.
+//
+// Returning target "" means "cast it on yourself": the caller drops the @mention,
+// and the engine's ordinary self-heal path takes it.
+//
+// It considers the caster's own seat, and it runs for a solo fight, and BOTH of
+// those are recent. Until now the rule skipped `i == seat` and bailed on
+// `!sess.IsParty()`, which together meant something nobody had said out loud: **no
+// autopiloted caster in this game had ever cast a heal on themselves.** A solo
+// cleric carried cure_wounds for a whole 30-room run and used it exactly never,
+// while dying with a full pool of level-1 slots. That is a strong candidate for
+// why the class corpus has cleric at 46–56% against fighter's 82%
+// ([[project_d8prereq_baseline]], §6 of the combat-engine plan) — the picker was
+// not playing the class.
+//
+// The healer heals whoever is worst off. Usually that is the friend bleeding out
+// next to them. Sometimes it is them.
+func simPickHeal(c *DnDCharacter, uid id.UserID, sess *CombatSession, seat int) (spellID, target string) {
+	if sess == nil || c == nil || !isSpellcaster(c) {
+		return "", ""
+	}
+
+	// Who is worst off? Only living seats — the engine will not raise the downed,
+	// and a heal aimed at a corpse is a lost turn.
+	worst, worstPct := -1, 101
+	for i := range sess.RosterSize() {
+		hp, hpMax := sess.seatHP(i), sess.seatHPMax(i)
+		if hp <= 0 || hpMax <= 0 {
+			continue
+		}
+		if pct := hp * 100 / hpMax; pct < worstPct {
+			worst, worstPct = i, pct
+		}
+	}
+	if worst < 0 || worstPct >= simHealAllyThresholdPct {
+		return "", ""
+	}
+	// Healing yourself is not an ally-target at all — it is the plain self-heal the
+	// engine has always had. Hand the caller no target and let it say so.
+	if worst == seat {
+		return simPickHealSpell(c, uid, sess, seat), ""
+	}
+
+	best := simPickHealSpell(c, uid, sess, seat)
+	if best == "" {
+		return "", ""
+	}
+	// Target by the seat's own Matrix localpart: splitCastTarget resolves against
+	// the seats in this fight, so this round-trips without a room lookup.
+	return best, id.UserID(sess.seatUserID(worst)).Localpart()
+}
+
+// simPickHealSpell is the cheapest heal this caster can actually cast right now,
+// or "". Burning a 5th-level slot to top somebody up is not what a competent
+// player does, so it takes the lowest castable slot.
+func simPickHealSpell(c *DnDCharacter, uid id.UserID, sess *CombatSession, seat int) string {
+	known, err := seatKnownSpells(sess, seat, uid)
+	if err != nil {
+		return ""
+	}
+	slots, _ := seatSpellSlots(sess, seat, uid)
+	best, bestLevel := "", 99
+	for _, k := range known {
+		if !k.Prepared {
+			continue
+		}
+		sp, ok := lookupSpell(k.SpellID)
+		if !ok || sp.Effect != EffectSpellHeal || sp.CastTime == CastReaction {
+			continue
+		}
+		onList := false
+		for _, cl := range sp.Classes {
+			if cl == c.Class {
+				onList = true
+				break
+			}
+		}
+		if !onList || sp.Level == 0 {
+			continue // heals are slot spells; a level-0 "heal" is not a thing we cast
+		}
+		if pair, ok := slots[sp.Level]; !ok || pair[0]-pair[1] <= 0 {
+			continue
+		}
+		if sp.Level < bestLevel {
+			best, bestLevel = sp.ID, sp.Level
+		}
+	}
+	return best
+}
+
+func simPickSpell(c *DnDCharacter, sess *CombatSession, seat int, uid id.UserID, auraActive bool) string {
+	known, err := seatKnownSpells(sess, seat, uid)
 	if err != nil || len(known) == 0 {
 		return ""
 	}
-	slots, _ := getSpellSlots(uid)
+	slots, _ := seatSpellSlots(sess, seat, uid)
 	type cand struct {
 		id          string
 		slot        int

internal/plugin/pete_retreat_test.go

@@ -0,0 +1,162 @@
+package plugin
+
+import (
+	"encoding/json"
+	"testing"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// The retreat bulletin: the news can finally say "it went badly and nobody
+// died". Before this, every event type Pete could file was a win, a death, or an
+// introduction — so a run that simply fell apart was reported as nothing at all,
+// and a class that retreated a third of the time just looked absent from the
+// feed.
+//
+// The reason gate is the whole safety property. A death must not ALSO be filed
+// as a retreat (it already files its own priority dispatch), and an idle reap
+// must not be filed at all — Pete telling the realm that a named player was
+// driven from the field, when in truth they closed their laptop, is a lie about
+// a person by name.
+
+func retreatFactFor(t *testing.T, uid id.UserID) map[string]any {
+	t.Helper()
+	var payload string
+	err := db.Get().QueryRow(
+		`SELECT payload FROM pete_emit_queue WHERE guid LIKE 'retreat:%'`).Scan(&payload)
+	if err != nil {
+		t.Fatalf("no retreat fact queued: %v", err)
+	}
+	var f map[string]any
+	if err := json.Unmarshal([]byte(payload), &f); err != nil {
+		t.Fatal(err)
+	}
+	return f
+}
+
+func TestRetreatNews_ReasonGate(t *testing.T) {
+	cases := []struct {
+		reason string
+		want   int
+		why    string
+	}{
+		{lossCombatRetreat, 1, "a solo walker who ran out the clock and withdrew is news"},
+		{lossCombatFlee, 1, "a party that broke off is news"},
+		{lossCombatDeath, 0, "a death already files its own priority dispatch — do not double-report it as a retreat"},
+		{lossIdleTimeout, 0, "an idle reap is not a retreat; the player closed their laptop, they did not flee"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.reason, func(t *testing.T) {
+			setupEmptyTestDB(t)
+			enablePeteSeam(t)
+			uid := id.UserID("@retreat:example.org")
+			zoneCmdTestCharacter(t, uid, 10)
+
+			emitRetreatNews(uid, tc.reason, ZoneID("underforge"), 3)
+
+			if got := queuedCount(t, "retreat:%"); got != tc.want {
+				t.Fatalf("reason %q queued %d retreat facts, want %d — %s",
+					tc.reason, got, tc.want, tc.why)
+			}
+		})
+	}
+}
+
+// The bulletin has to carry enough for Pete to write a sentence: who, where, how
+// far they got. A retreat with no day count is just "someone left".
+func TestRetreatNews_CarriesTheStory(t *testing.T) {
+	setupEmptyTestDB(t)
+	enablePeteSeam(t)
+	uid := id.UserID("@retreat-story:example.org")
+	zoneCmdTestCharacter(t, uid, 10)
+
+	emitRetreatNews(uid, lossCombatRetreat, ZoneID("underforge"), 3)
+
+	f := retreatFactFor(t, uid)
+	if f["event_type"] != "retreat" {
+		t.Errorf("event_type = %v, want retreat", f["event_type"])
+	}
+	// Bulletin, not priority: a retreat is a bad day, not a funeral.
+	if f["tier"] != "bulletin" {
+		t.Errorf("tier = %v, want bulletin", f["tier"])
+	}
+	if f["outcome"] != "retreated" {
+		t.Errorf("outcome = %v, want retreated", f["outcome"])
+	}
+	if f["count"] != float64(3) {
+		t.Errorf("count = %v, want 3 (the day it fell apart)", f["count"])
+	}
+	if f["zone"] == nil || f["zone"] == "" {
+		t.Error("no zone — Pete cannot say where it happened")
+	}
+	if f["subject"] == nil || f["subject"] == "" {
+		t.Error("no subject — Pete cannot say who it happened to")
+	}
+	// GUID prefix must equal the event type; Pete's taxonomy keys off it.
+	if guid, _ := f["guid"].(string); len(guid) < 8 || guid[:8] != "retreat:" {
+		t.Errorf("guid %q must be prefixed with the event type", guid)
+	}
+}
+
+// The wiring, not just the emitter. Everything above calls emitRetreatNews
+// directly, which proves nothing about the game: the fact only ships if the real
+// run-loss chokepoint actually calls it, on a real expedition, and reads the day
+// count BEFORE forcedExtractExpedition stamps the row 'abandoned' and takes the
+// live fields with it. Drive the chokepoint.
+func TestRetreatNews_WiredToTheRunLossChokepoint(t *testing.T) {
+	setupEmptyTestDB(t)
+	enablePeteSeam(t)
+	uid := id.UserID("@retreat-wired:example")
+	campTestCharacter(t, uid, 1)
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneGoblinWarrens, "",
+		ExpeditionSupplies{Current: 5, Max: 5, DailyBurn: 1, HarshMod: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	forceExtractExpeditionForRunLoss(uid, lossCombatRetreat)
+
+	if got := queuedCount(t, "retreat:%"); got != 1 {
+		t.Fatalf("the run-loss chokepoint queued %d retreat facts, want 1 — "+
+			"emitRetreatNews passes its own unit tests but is not actually wired to the game", got)
+	}
+	f := retreatFactFor(t, uid)
+	// The day must survive the extract. Read it after forcedExtractExpedition and
+	// it is gone — the row is 'abandoned' and the live fields are zeroed.
+	if f["count"] != float64(exp.CurrentDay) {
+		t.Errorf("count = %v, want %d — the day count was read after the extract wiped it",
+			f["count"], exp.CurrentDay)
+	}
+	// And the expedition really did end; a bulletin about a run still in progress
+	// would be worse than no bulletin.
+	if still, _ := getActiveExpedition(uid); still != nil {
+		t.Error("expedition still active after a run-loss extract")
+	}
+}
+
+// The opt-out covers the new event type too. A player who asked not to be named
+// must not be named when they lose — that is precisely when they'd mind most.
+func TestRetreatNews_HonoursOptOut(t *testing.T) {
+	setupEmptyTestDB(t)
+	enablePeteSeam(t)
+	uid := id.UserID("@retreat-shy:example.org")
+	zoneCmdTestCharacter(t, uid, 10)
+	setNewsOptout(uid, true)
+
+	emitRetreatNews(uid, lossCombatRetreat, ZoneID("underforge"), 2)
+
+	f := retreatFactFor(t, uid)
+	if f["subject"] != anonName {
+		t.Fatalf("subject = %v, want %q — the opt-out must cover retreats", f["subject"], anonName)
+	}
+	actors, _ := f["actors"].([]any)
+	for _, a := range actors {
+		if a != anonName {
+			t.Fatalf("actors leaked %v past the opt-out", a)
+		}
+	}
+}

internal/plugin/zone_combat_autocast.go

@@ -0,0 +1,151 @@
+package plugin
+
+import (
+	"maunium.net/go/mautrix/id"
+)
+
+// §6 — a caster casts in an auto-resolved fight.
+//
+// An ordinary room fight is runZoneCombatRoster → SimulateCombat on an 8-round
+// clock: one breath, no turn engine, no action picker. The only spell that has
+// ever landed there is a PendingCast the player queued BY HAND with `!cast`
+// before walking in. Under autopilot nobody queues one — so for every room of
+// every expedition, a caster fought with a weapon and nothing else.
+//
+// A cleric is the extreme case: no Extra Attack, a mace, and its whole kit
+// unusable. Measured on the room path at L10, a wounded cleric loses 8% of
+// ORDINARY room fights (a fighter loses 0.0%), and a room loss ends the entire
+// expedition — "the fight drags on, X outlasts you, you retreat". That is why
+// cleric fled 167 of 500 runs in the corpus while fighter, ranger and paladin
+// fled none, and it is the whole of the "cleric is a weak class" gap.
+//
+// The tell: dnd_class_balance.go — the harness the class corpus was tuned on —
+// ALWAYS hands a caster their best damage spell (pickBestDamageSpell +
+// applyHarnessSpellCast) before it simulates. So the numbers we balanced against
+// modelled a caster who casts, and the live room modelled one who does not. This
+// closes that gap: the character fights with the kit it actually owns.
+//
+// It is NOT a new mechanic. A folded-in spell is additive pre-damage, exactly as
+// a hand-queued PendingCast has always been, which is what keeps this comparable
+// to the corpus rather than a fresh invention.
+
+// autoCastForAutoResolve picks the caster's best damage spell, spends the slot,
+// and folds the damage into the Combatant pair. Reports whether it cast.
+//
+// It reads the seat's ACTUAL remaining slots, not the class slot table.
+// pickBestDamageSpell (the harness one) reads slotsForClassLevel — the
+// theoretical pool — which is right for a one-fight harness and would be an
+// infinite spell here: the same "no row to persist onto, so it arrives fresh"
+// bug that gave the companion an unlimited body and an unlimited slot pool.
+// A leveled spell cast here costs a real slot and stays spent until a rest.
+func (p *AdventurePlugin) autoCastForAutoResolve(
+	uid id.UserID,
+	c *DnDCharacter,
+	playerStats *CombatStats,
+	playerMods *CombatModifiers,
+	enemyStats *CombatStats,
+) bool {
+	// A hand-queued spell wins: the player already chose, applyPendingCast owns
+	// it, and casting a second one would be two spells in one action.
+	if c == nil || c.PendingCast != "" || !isSpellcaster(c) {
+		return false
+	}
+	spell, slot, ok := pickAutoResolveSpell(uid, c)
+	if !ok {
+		return false
+	}
+	// Leveled spells cost a slot. Spend it BEFORE the damage lands, and bail if
+	// the debit fails — a spell that could not be paid for must not be cast.
+	if slot > 0 {
+		spent, err := consumeSpellSlot(uid, slot)
+		if err != nil || !spent {
+			return false
+		}
+	}
+	applyHarnessSpellCast(c, spell, slot, playerStats, playerMods, enemyStats)
+	return true
+}
+
+// roomSlotCap is the highest slot level an ordinary room may spend. Cantrips are
+// free and always available; anything above this is reserved for the elite and
+// the boss.
+//
+// The first cut of §6 had no cap — "never upcast" was supposed to be enough. It
+// was not, and the sweep said so: room deaths fell for every caster (mage 131 →
+// 105) while elite and boss deaths exploded (mage 7 → 38 and 19 → 61, sorcerer
+// 14 → 51 and 15 → 65). Casters were winning the trash rooms and arriving at the
+// thing that matters with an empty pool. Native-level is not a reserve, because
+// a mage's native-level spells ARE its boss kit; only a level cap is.
+//
+// 2 is where the two demands stop overlapping. Every caster owns a damage spell
+// at or below it (a cleric's guiding_bolt and inflict_wounds are both 1st), so
+// the rooms still get a real spell — but a fireball, a spirit_guardians, a
+// flame_strike, and every slot the turn engine would upcast into stays in the
+// caster's pocket until there is something worth spending it on.
+const roomSlotCap = 2
+
+// pickAutoResolveSpell is the best damage spell this caster can actually cast
+// right now: known, prepared, on their list, at or under the room slot cap, and
+// backed by a slot they still hold.
+//
+// It casts at the spell's NATIVE level and never upcasts. simPickSpell upcasts
+// aggressively — correct there, because it runs in the turn engine at an elite
+// or a boss, which is what the big slots are for. A trash room is not, and a
+// picker that nukes a goblin with a 5th-level slot would leave the caster
+// swinging a stick at the thing that actually matters.
+func pickAutoResolveSpell(uid id.UserID, c *DnDCharacter) (SpellDefinition, int, bool) {
+	known, err := listKnownSpells(uid)
+	if err != nil || len(known) == 0 {
+		return SpellDefinition{}, 0, false
+	}
+	slots, err := getSpellSlots(uid)
+	if err != nil {
+		return SpellDefinition{}, 0, false
+	}
+
+	var best SpellDefinition
+	bestSlot := 0
+	bestScore := -1.0
+	for _, k := range known {
+		if !k.Prepared {
+			continue
+		}
+		sp, ok := lookupSpell(k.SpellID)
+		if !ok {
+			continue
+		}
+		switch sp.Effect {
+		case EffectDamageAttack, EffectDamageSave, EffectDamageAuto:
+		default:
+			continue
+		}
+		// The auto-resolve engine has no reaction window, same as everywhere else.
+		if sp.CastTime == CastReaction {
+			continue
+		}
+		onList := false
+		for _, cl := range sp.Classes {
+			if cl == c.Class {
+				onList = true
+				break
+			}
+		}
+		if !onList {
+			continue
+		}
+		// A cantrip is free; a leveled spell needs a slot still in hand, and the
+		// room only gets to reach for the small ones.
+		if sp.Level > 0 {
+			if sp.Level > roomSlotCap {
+				continue
+			}
+			if pair, ok := slots[sp.Level]; !ok || pair[0]-pair[1] <= 0 {
+				continue
+			}
+		}
+		if score := spellExpectedDamage(sp, sp.Level, c.Level); score > bestScore {
+			best, bestSlot, bestScore = sp, sp.Level, score
+		}
+	}
+	return best, bestSlot, bestScore >= 0
+}

internal/plugin/zone_combat_autocast_test.go

@@ -0,0 +1,254 @@
+package plugin
+
+import (
+	"testing"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// §6 — the caster casts in an auto-resolved room fight.
+//
+// Before this, the ONLY spell that could land in an ordinary room was one the
+// player hand-queued with `!cast` before walking in. On autopilot nobody queues
+// one, so a cleric fought every room of every expedition with a mace, lost room
+// fights a fighter never loses, and a room loss ends the whole expedition.
+
+func autocastCleric(t *testing.T, tag string) (id.UserID, *DnDCharacter) {
+	t.Helper()
+	p := &AdventurePlugin{}
+	s := &SimRunner{P: p}
+	uid := id.UserID("@autocast-" + tag + ":example.org")
+	c, err := s.BuildCharacter(uid, ClassCleric, 10)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return uid, c
+}
+
+func usedSlots(t *testing.T, uid id.UserID) int {
+	t.Helper()
+	slots, err := getSpellSlots(uid)
+	if err != nil {
+		t.Fatal(err)
+	}
+	total := 0
+	for _, pair := range slots {
+		total += pair[1]
+	}
+	return total
+}
+
+func TestAutoCast_CasterCastsAndPaysForIt(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	uid, c := autocastCleric(t, "pays")
+
+	var mods CombatModifiers
+	stats := CombatStats{MaxHP: 100, AC: 14}
+	enemy := CombatStats{MaxHP: 100, AC: 14}
+
+	if !p.autoCastForAutoResolve(uid, c, &stats, &mods, &enemy) {
+		t.Fatal("a level-10 cleric with a full slot pool cast nothing")
+	}
+	// It has to be PAID for. pickBestDamageSpell reads the theoretical class slot
+	// table; if we had reused it here the spell would be infinite — the same
+	// free-lunch bug that gave the companion an unlimited body. The slot is spent
+	// whether or not the spell connects, exactly as it is at a real table.
+	if used := usedSlots(t, uid); used != 1 {
+		t.Fatalf("slots used = %d, want exactly 1 — the spell must cost a real slot", used)
+	}
+}
+
+// The slot has to buy damage. Not on any GIVEN cast — under the room slot cap a
+// cleric reaches for inflict_wounds, which is an attack-roll spell and is
+// allowed to miss — but a caster who spends its pool and never scratches
+// anything would be strictly worse than swinging the mace.
+func TestAutoCast_SpellActuallyDealsDamage(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	uid, c := autocastCleric(t, "damage")
+
+	landed := 0
+	for i := 0; i < 40; i++ {
+		var mods CombatModifiers
+		stats := CombatStats{MaxHP: 100, AC: 14}
+		enemy := CombatStats{MaxHP: 1000, AC: 10}
+		if !p.autoCastForAutoResolve(uid, c, &stats, &mods, &enemy) {
+			continue
+		}
+		if mods.SpellPreDamage > 0 || enemy.MaxHP < 1000 {
+			landed++
+		}
+	}
+	if landed == 0 {
+		t.Fatal("40 casts against AC 10 and not one dealt a point of damage — " +
+			"the caster is spending slots on air")
+	}
+}
+
+// The pool is finite: cast far more times than the caster has slots, and the
+// ledger must converge rather than run forever. This is the free-lunch guard —
+// reusing the harness's pickBestDamageSpell (which reads the theoretical class
+// slot table, not the row) would cast an unlimited leveled spell every room.
+//
+// It converges BELOW the full pool, and that is correct: a cleric owns no damage
+// spell at slot 2 or 4 (guiding_bolt and inflict_wounds are L1, spirit_guardians
+// L3, flame_strike L5), and a trash room never upcasts. Those slots are not
+// wasted — the turn engine upcasts them at the elite and the boss, which is what
+// they are for.
+func TestAutoCast_SlotPoolIsFiniteAndConverges(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	uid, c := autocastCleric(t, "finite")
+
+	before, err := getSpellSlots(uid)
+	if err != nil {
+		t.Fatal(err)
+	}
+	pool := 0
+	for _, pair := range before {
+		pool += pair[0]
+	}
+	if pool == 0 {
+		t.Fatal("test cleric has no slots at all")
+	}
+
+	cast := func(n int) {
+		for i := 0; i < n; i++ {
+			var mods CombatModifiers
+			stats := CombatStats{MaxHP: 100, AC: 14}
+			enemy := CombatStats{MaxHP: 1000, AC: 14}
+			p.autoCastForAutoResolve(uid, c, &stats, &mods, &enemy)
+		}
+	}
+
+	cast(pool + 10)
+	drained := usedSlots(t, uid)
+	if drained == 0 {
+		t.Fatal("the cleric never spent a slot — it is not really casting")
+	}
+	if drained > pool {
+		t.Fatalf("slots used = %d > pool %d — slots are being conjured", drained, pool)
+	}
+
+	// Dry means dry: another twenty rooms must not find another leveled slot.
+	cast(20)
+	if after := usedSlots(t, uid); after != drained {
+		t.Fatalf("slots used went %d → %d after the pool was dry — a leveled spell is being cast for free",
+			drained, after)
+	}
+
+	// And a dry caster still throws a cantrip rather than reverting to a stick.
+	var mods CombatModifiers
+	stats := CombatStats{MaxHP: 100, AC: 14}
+	enemy := CombatStats{MaxHP: 1000, AC: 14}
+	if !p.autoCastForAutoResolve(uid, c, &stats, &mods, &enemy) {
+		t.Fatal("an out-of-slots caster cast nothing at all; a cantrip is free")
+	}
+}
+
+// A hand-queued spell wins. applyPendingCast already owns that cast; auto-casting
+// on top of it would fire two spells in one action.
+func TestAutoCast_HandQueuedSpellWins(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	uid, c := autocastCleric(t, "queued")
+
+	c.PendingCast = encodePendingCast(PendingCast{SpellID: "guiding_bolt", SlotLevel: 1})
+	if err := SaveDnDCharacter(c); err != nil {
+		t.Fatal(err)
+	}
+	var mods CombatModifiers
+	stats := CombatStats{MaxHP: 100, AC: 14}
+	enemy := CombatStats{MaxHP: 100, AC: 14}
+	if p.autoCastForAutoResolve(uid, c, &stats, &mods, &enemy) {
+		t.Fatal("auto-cast fired on top of a hand-queued spell — that is two spells in one action")
+	}
+	if used := usedSlots(t, uid); used != 0 {
+		t.Fatalf("slots used = %d; the auto-cast must not spend anything when the player already queued", used)
+	}
+}
+
+// A martial has no spellbook and must be left exactly as it was — the balance
+// corpus rests on the martials not moving.
+func TestAutoCast_MartialIsUntouched(t *testing.T) {
+	setupEmptyTestDB(t)
+	p := &AdventurePlugin{}
+	s := &SimRunner{P: p}
+	uid := id.UserID("@autocast-fighter:example.org")
+	c, err := s.BuildCharacter(uid, ClassFighter, 10)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var mods CombatModifiers
+	stats := CombatStats{MaxHP: 100, AC: 14}
+	enemy := CombatStats{MaxHP: 100, AC: 14}
+	if p.autoCastForAutoResolve(uid, c, &stats, &mods, &enemy) {
+		t.Fatal("a fighter cast a spell")
+	}
+	if mods.SpellPreDamage != 0 {
+		t.Fatalf("fighter picked up %d spell pre-damage", mods.SpellPreDamage)
+	}
+}
+
+// Never upcast in a trash room: the big slots are what the elite and the boss
+// are for, and the turn engine spends them there.
+func TestAutoCast_DoesNotBurnTheBigSlots(t *testing.T) {
+	setupEmptyTestDB(t)
+	uid, c := autocastCleric(t, "native")
+
+	spell, slot, ok := pickAutoResolveSpell(uid, c)
+	if !ok {
+		t.Fatal("cleric picked nothing")
+	}
+	if slot != spell.Level {
+		t.Fatalf("%s cast at slot %d, native level %d — an ordinary room must not upcast",
+			spell.ID, slot, spell.Level)
+	}
+}
+
+// The boss kit survives the walk in. This is the regression the first cut of §6
+// shipped and the sweep caught: with no cap, a caster spent its whole pool on
+// goblins and reached the boss empty — room deaths fell but boss deaths tripled
+// (mage 19 → 61, sorcerer 15 → 65). "Never upcast" is not a reserve, because a
+// mage's native-level spells ARE its boss kit.
+//
+// So: grind a full expedition's worth of rooms, and every slot above the cap
+// must still be sitting there untouched when the dragon opens its eyes.
+func TestAutoCast_ReservesTheBossSlots(t *testing.T) {
+	for _, class := range []DnDClass{ClassMage, ClassSorcerer, ClassCleric, ClassWarlock} {
+		t.Run(string(class), func(t *testing.T) {
+			setupEmptyTestDB(t)
+			p := &AdventurePlugin{}
+			s := &SimRunner{P: p}
+			uid := id.UserID("@autocast-reserve-" + string(class) + ":example.org")
+			c, err := s.BuildCharacter(uid, class, 12)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			// A long expedition: far more rooms than the caster has slots.
+			for i := 0; i < 60; i++ {
+				var mods CombatModifiers
+				stats := CombatStats{MaxHP: 100, AC: 14}
+				enemy := CombatStats{MaxHP: 1000, AC: 14}
+				p.autoCastForAutoResolve(uid, c, &stats, &mods, &enemy)
+			}
+
+			slots, err := getSpellSlots(uid)
+			if err != nil {
+				t.Fatal(err)
+			}
+			for lvl, pair := range slots {
+				if lvl <= roomSlotCap {
+					continue
+				}
+				if pair[1] != 0 {
+					t.Errorf("level-%d slots: %d of %d spent in ordinary rooms — "+
+						"that is the boss's kit, and the caster will arrive empty",
+						lvl, pair[1], pair[0])
+				}
+			}
+		})
+	}
+}

internal/plugin/zone_combat_party.go

@@ -51,6 +51,11 @@ func (p *AdventurePlugin) runZoneCombatRoster(
 		advChar *AdventureCharacter
 		equip   map[EquipmentSlot]*AdvEquipment
 		mods    CombatModifiers
+		// companion marks the hired NPC seat: it fights, but it owns none of the
+		// character-scoped effects the close-out loop applies, and its dndChar /
+		// advChar / equip are nil precisely so a missed guard panics loudly here
+		// rather than silently writing rows for a bot.
+		companion bool
 	}
 
 	var (
@@ -58,6 +63,10 @@ func (p *AdventurePlugin) runZoneCombatRoster(
 		builds  []seatBuild
 		seated  []id.UserID
 		enemy   Combatant
+		// Parallel to players: what each seat is worth, priced once the roster is
+		// final. A member who sat the encounter out is in none of these.
+		levels     []int
+		companions []bool
 	)
 
 	for i, uid := range roster {
@@ -69,6 +78,29 @@ func (p *AdventurePlugin) runZoneCombatRoster(
 			return PartyCombatResult{}, nil, err
 		}
 
+		// The hired companion fights here too — the auto-resolve path is where
+		// most expedition rooms are actually decided. He is synthesized rather
+		// than loaded, and his seatBuild is flagged so the close-out loop below
+		// gives him no XP, no loot, and no post-combat persistence.
+		if isCompanionSeat(uid) {
+			expID := companionExpeditionFor(roster[0])
+			class, level := companionLoadout(expID)
+			player, e, _ := p.companionCombatant(class, level, monster, tier, dmMood)
+			// The wounds he carries into this fight. His synthetic sheet is always
+			// written at full HP, so applyDnDHPScaling left StartHP at the
+			// "enter at MaxHP" sentinel and he healed himself for free between every
+			// room of the run. See companionSeatHP.
+			player.Stats.StartHP = companionSeatHP(expID, player.Stats.MaxHP)
+			if leader {
+				enemy = e
+			}
+			players = append(players, player)
+			builds = append(builds, seatBuild{uid: uid, mods: player.Mods, companion: true})
+			seated = append(seated, uid)
+			levels, companions = append(levels, level), append(companions, true)
+			continue
+		}
+
 		advChar, err := loadAdvCharacter(uid)
 		if err != nil || advChar == nil {
 			if leader {
@@ -120,6 +152,11 @@ func (p *AdventurePlugin) runZoneCombatRoster(
 		// Combatant once, before the fight runs. The queued spell can also debuff
 		// the shared enemy, so every seat's cast lands on the one stat block.
 		applyPendingCast(uid, dndChar, &player.Stats, &player.Mods, &enemy.Stats)
+		// §6 — and if they queued nothing, they still cast. This engine has no
+		// action picker, so before this a caster on autopilot swung a weapon for
+		// the whole fight and their spellbook may as well not have existed. The
+		// slot is really spent; see autoCastForAutoResolve.
+		p.autoCastForAutoResolve(uid, dndChar, &player.Stats, &player.Mods, &enemy.Stats)
 		setupAutoHealFromInventory(p.loadConsumableInventory(uid), &player.Mods)
 
 		players = append(players, player)
@@ -127,7 +164,20 @@ func (p *AdventurePlugin) runZoneCombatRoster(
 			uid: uid, dndChar: dndChar, advChar: advChar, equip: equip, mods: player.Mods,
 		})
 		seated = append(seated, uid)
+		lvl := 0
+		if dndChar != nil {
+			lvl = dndChar.Level
 		}
+		levels, companions = append(levels, lvl), append(companions, false)
+	}
+
+	// What each seat costs the enemy, priced against the leader — over the seats
+	// that were actually seated, so a member left behind is not charged.
+	ptrs := make([]*Combatant, len(players))
+	for i := range players {
+		ptrs[i] = &players[i]
+	}
+	applySeatWeights(ptrs, levels, companions)
 
 	res := simulateParty(players, enemy, phases)
 	dumpCombatEventsIfDebug(
@@ -137,6 +187,19 @@ func (p *AdventurePlugin) runZoneCombatRoster(
 	for i, b := range builds {
 		seatRes := res.Seats[i]
 
+		// The companion swings and then goes back to filing copy: no inventory to
+		// deduct from, no sheet to persist to, no XP to earn. Every call below
+		// would either write rows for a bot or log an error about the rows it
+		// hasn't got.
+		//
+		// His HP is the exception, and it is not bookkeeping — it is the fight's
+		// result. Without it he re-enters the next room at full while the humans
+		// beside him carry every wound to camp.
+		if b.companion {
+			_ = setCompanionHP(companionExpeditionFor(roster[0]), seatRes.PlayerEndHP)
+			continue
+		}
+
 		// Remove the actual heal items consumed during combat (one inventory item
 		// per heal_item event this seat fired). Cheapest-tier first.
 		consumeFiredHealingItems(b.uid, countHealEventsFired(seatRes))
@@ -193,6 +256,12 @@ func (p *AdventurePlugin) closeOutZoneWin(
 ) (leaderDrop string, downed []id.UserID) {
 	party := len(seated) > 1
 	for i, uid := range seated {
+		// The companion takes no cut and cannot die. He is not in the downed list
+		// either: that list is what the room narration mourns, and the party did
+		// not lose a friend when the hireling took a nap.
+		if isCompanionSeat(uid) {
+			continue
+		}
 		if res.Seats[i].PlayerEndHP > 0 {
 			drop := p.dropZoneLoot(uid, zone.ID, monster, isBoss, elite)
 			if i == 0 {
@@ -217,6 +286,12 @@ func (p *AdventurePlugin) closeOutZoneWin(
 // fight.
 func closeOutZoneLoss(res PartyCombatResult, seated []id.UserID, zone ZoneDefinition, deathSource string) (killed []id.UserID) {
 	for i, uid := range seated {
+		// The companion is not killed and is not counted among the dead — he is
+		// not in the graveyard, and a wipe that lists him would have the news bot
+		// reporting its own funeral.
+		if isCompanionSeat(uid) {
+			continue
+		}
 		if res.Seats[i].PlayerEndHP <= 0 {
 			markAdventureDead(uid, deathSource, zone.Display)
 			killed = append(killed, uid)