diff --git a/internal/db/db.go b/internal/db/db.go
index a183e42..0bcc8cf 100644
--- a/internal/db/db.go
+++ b/internal/db/db.go
@@ -1373,6 +1373,75 @@ CREATE TABLE IF NOT EXISTS holdem_tip_audit (
 CREATE INDEX IF NOT EXISTS idx_tip_audit_user ON holdem_tip_audit(user_id);
 CREATE INDEX IF NOT EXISTS idx_tip_audit_action ON holdem_tip_audit(action, street);
 
+-- Co-op Dungeon (party multi-day runs)
+CREATE TABLE IF NOT EXISTS coop_dungeon_runs (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    tier            INTEGER NOT NULL,
+    status          TEXT NOT NULL DEFAULT 'open',  -- open, active, complete, wiped, cancelled
+    leader_id       TEXT NOT NULL,
+    current_day     INTEGER NOT NULL DEFAULT 0,
+    total_days      INTEGER NOT NULL,
+    base_difficulty INTEGER NOT NULL,              -- per-floor failure % at zero modifier
+    gold_pool       INTEGER NOT NULL DEFAULT 0,    -- accumulated funding
+    reward_total    INTEGER NOT NULL DEFAULT 0,    -- final reward (set on completion)
+    created_at      DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    locked_at       DATETIME,
+    completed_at    DATETIME
+);
+CREATE INDEX IF NOT EXISTS idx_coop_runs_status ON coop_dungeon_runs(status);
+
+CREATE TABLE IF NOT EXISTS coop_dungeon_members (
+    run_id            INTEGER NOT NULL,
+    user_id           TEXT NOT NULL,
+    turn_order        INTEGER NOT NULL,
+    total_contributed INTEGER NOT NULL DEFAULT 0,
+    is_liability      INTEGER NOT NULL DEFAULT 0,
+    daily_funding     TEXT NOT NULL DEFAULT '{}',  -- JSON: {"1":"standard","2":"all_in",...}
+    PRIMARY KEY (run_id, user_id)
+);
+CREATE INDEX IF NOT EXISTS idx_coop_members_user ON coop_dungeon_members(user_id);
+
+CREATE TABLE IF NOT EXISTS coop_dungeon_events (
+    run_id           INTEGER NOT NULL,
+    day              INTEGER NOT NULL,
+    category         TEXT NOT NULL,                  -- obstacle, opportunity, crisis, encounter
+    event_index      INTEGER NOT NULL,               -- index into the category flavor pool
+    recommended      TEXT NOT NULL,                  -- A, B, or C — TwinBee's pick
+    votes            TEXT NOT NULL DEFAULT '{}',     -- JSON {"@user:host": "A"}
+    winning_vote     TEXT DEFAULT NULL,
+    outcome          TEXT DEFAULT NULL,              -- 'success' or 'failure' (after resolution)
+    modifier_applied INTEGER DEFAULT 0,
+    post_event_id    TEXT DEFAULT NULL,              -- Matrix event ID for live edit
+    PRIMARY KEY (run_id, day)
+);
+CREATE INDEX IF NOT EXISTS idx_coop_events_outcome ON coop_dungeon_events(outcome);
+
+CREATE TABLE IF NOT EXISTS coop_dungeon_bets (
+    run_id     INTEGER NOT NULL,
+    player_id  TEXT NOT NULL,
+    position   TEXT NOT NULL,                 -- 'success' or 'failure'
+    amount     INTEGER NOT NULL,
+    placed_at  DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    payout     INTEGER,                       -- NULL until run resolves
+    PRIMARY KEY (run_id, player_id)
+);
+CREATE INDEX IF NOT EXISTS idx_coop_bets_run ON coop_dungeon_bets(run_id);
+
+CREATE TABLE IF NOT EXISTS coop_dungeon_gifts (
+    id            INTEGER PRIMARY KEY AUTOINCREMENT,
+    run_id        INTEGER NOT NULL,
+    sender_id     TEXT NOT NULL,
+    day           INTEGER NOT NULL,
+    gift_type     TEXT NOT NULL,                 -- 'basket' or 'mimic'
+    votes         TEXT NOT NULL DEFAULT '{}',    -- JSON {"@user:host": "open"|"leave"}
+    vote_result   TEXT,                          -- 'opened' or 'left'
+    outcome       TEXT,                          -- 'boost' or 'reduction'
+    modifier      INTEGER NOT NULL DEFAULT 0,
+    post_event_id TEXT,
+    sent_at       DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    resolved_at   DATETIME
+);
+CREATE INDEX IF NOT EXISTS idx_coop_gifts_run_day ON coop_dungeon_gifts(run_id, day, vote_result);
 `
 
 // SeedSchedulerDefaults inserts default scheduler jobs if they don't exist.
diff --git a/internal/plugin/adventure.go b/internal/plugin/adventure.go
index 6b9f6fc..bff3278 100644
--- a/internal/plugin/adventure.go
+++ b/internal/plugin/adventure.go
@@ -141,6 +141,7 @@ func (p *AdventurePlugin) Init() error {
 	go p.robbieTicker()
 	go p.hospitalNudgeTicker()
 	go p.mortgageTicker()
+	go p.coopTicker()
 
 	// Auto-cashout any arena runs left in 'awaiting' from a prior restart
 	p.arenaCleanupStaleRuns()
@@ -185,6 +186,11 @@ func (p *AdventurePlugin) OnMessage(ctx MessageContext) error {
 		return p.handleHospitalCmd(ctx)
 	}
 
+	// 1c. Co-op dungeon commands (work in rooms and DMs)
+	if p.IsCommand(ctx.Body, "coop") {
+		return p.handleCoopCmd(ctx)
+	}
+
 	// 2. Check if this is a DM reply from a registered player
 	p.mu.Lock()
 	playerID, isDM := p.dmToPlayer[ctx.RoomID]
@@ -281,6 +287,7 @@ const advHelpText = `**Adventure Commands**
 ` + "`!adventure blacksmith`" + ` — Visit the blacksmith (view repair costs)
 ` + "`!adventure repair all`" + ` — Repair all damaged equipment
 ` + "`!adventure repair <slot>`" + ` — Repair a specific slot
+` + "`!coop`" + ` — Co-op dungeons (multi-day party runs). See ` + "`!coop help`" + `.
 ` + "`!hospital`" + ` — Visit St. Guildmore's Memorial Hospital (same-day revival when dead)
 ` + "`!thom`" + ` — Visit Thom Krooke (housing and loans)
 ` + "`!adventure help`" + ` — This message
diff --git a/internal/plugin/coop_dungeon.go b/internal/plugin/coop_dungeon.go
new file mode 100644
index 0000000..a46a14c
--- /dev/null
+++ b/internal/plugin/coop_dungeon.go
@@ -0,0 +1,462 @@
+package plugin
+
+import (
+	"fmt"
+	"log/slog"
+	"strconv"
+	"strings"
+	"time"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// ── Balance Constants ───────────────────────────────────────────────────────
+//
+// Phase 1 values. Adjust during balance pass. Co-op should feel meaningfully
+// harder than solo and reward groups for showing up.
+
+type CoopFundingTier string
+
+const (
+	CoopFundNone       CoopFundingTier = "none"
+	CoopFundMinimal    CoopFundingTier = "minimal"
+	CoopFundStandard   CoopFundingTier = "standard"
+	CoopFundAggressive CoopFundingTier = "aggressive"
+	CoopFundAllIn      CoopFundingTier = "all_in"
+)
+
+type coopFundingDef struct {
+	cost     int
+	modifier int // % added to per-floor success roll
+	label    string
+}
+
+var coopFundingTable = map[CoopFundingTier]coopFundingDef{
+	CoopFundNone:       {0, -10, "None"},
+	CoopFundMinimal:    {500, 0, "Minimal"},
+	CoopFundStandard:   {1500, 8, "Standard"},
+	CoopFundAggressive: {4000, 18, "Aggressive"},
+	CoopFundAllIn:      {10000, 30, "All In"},
+}
+
+// fundingTierOrder for menu display.
+var coopFundingOrder = []CoopFundingTier{
+	CoopFundMinimal, CoopFundStandard, CoopFundAggressive, CoopFundAllIn,
+}
+
+type coopTierDef struct {
+	totalDays      int
+	baseFailurePct int     // base % failure per floor at zero modifier
+	rewardBase     int     // base reward (gold) before split
+	difficulty     string  // label
+	minLevel       int     // newbie liability threshold
+	lootMult       float64 // for display only
+}
+
+// Reward bases tuned via Monte Carlo (coop_dungeon_balance_test.go) so the
+// optimal funding strategy walks up tiers: T1-T2 Minimal/Standard, T3 Standard,
+// T4 Standard or Aggressive, T5 Aggressive only. All-In stays -EV at every
+// tier — it's the boost lever for liability parties, not the optimal play.
+var coopTierTable = map[int]coopTierDef{
+	1: {2, 25, 22500, "Moderate", 5, 2.0},
+	2: {3, 32, 40000, "Hard", 12, 3.5},
+	3: {4, 40, 72500, "Very Hard", 20, 5.5},
+	4: {5, 48, 120000, "Brutal", 30, 8.0},
+	5: {7, 58, 600000, "Murderous", 40, 12.0},
+}
+
+const (
+	coopMinPartySize  = 2
+	coopMaxPartySize  = 4
+	coopInviteWindow  = 24 * time.Hour
+	coopLiabilityCap  = 8 // liability players' funding modifier capped at +8% regardless of tier
+	coopAdventureRake = 0.05
+)
+
+// ── Command Dispatch ────────────────────────────────────────────────────────
+
+func (p *AdventurePlugin) handleCoopCmd(ctx MessageContext) error {
+	args := strings.TrimSpace(p.GetArgs(ctx.Body, "coop"))
+	lower := strings.ToLower(args)
+
+	switch {
+	case args == "" || lower == "help":
+		return p.SendDM(ctx.Sender, coopHelpText)
+	case lower == "list":
+		return p.handleCoopList(ctx)
+	case lower == "status":
+		return p.handleCoopStatus(ctx)
+	case strings.HasPrefix(lower, "start "):
+		return p.handleCoopStart(ctx, strings.TrimSpace(args[6:]))
+	case strings.HasPrefix(lower, "join"):
+		return p.handleCoopJoin(ctx, strings.TrimSpace(strings.TrimPrefix(args, "join")))
+	case strings.HasPrefix(lower, "fund "):
+		return p.handleCoopFund(ctx, strings.TrimSpace(args[5:]))
+	case lower == "cancel":
+		return p.handleCoopCancel(ctx)
+	case strings.HasPrefix(lower, "vote "):
+		return p.handleCoopVote(ctx, strings.TrimSpace(args[5:]))
+	case strings.HasPrefix(lower, "bet "):
+		return p.handleCoopBet(ctx, strings.TrimSpace(args[4:]))
+	case strings.HasPrefix(lower, "gift "):
+		return p.handleCoopGift(ctx, strings.TrimSpace(args[5:]))
+	case strings.HasPrefix(lower, "giftvote "):
+		return p.handleCoopGiftVote(ctx, strings.TrimSpace(args[9:]))
+	}
+
+	return p.SendDM(ctx.Sender, "Unknown coop command. Try `!coop help`.")
+}
+
+const coopHelpText = `**Co-op Dungeon Commands**
+
+` + "`!coop list`" + ` — Show open invites
+` + "`!coop start <tier>`" + ` — Open an invite for a co-op dungeon (tier 1-5)
+` + "`!coop join [<run_id>]`" + ` — Join an open invite (defaults to most recent)
+` + "`!coop fund <tier>`" + ` — Set today's funding (none/minimal/standard/aggressive/all_in)
+` + "`!coop vote <A|B|C>`" + ` — Vote on the day's floor event
+` + "`!coop bet <amount> <success|failure>`" + ` — Spectator bet (parimutuel, 10% rake)
+` + "`!coop gift <run_id> <basket|mimic>`" + ` — Send a gift (1 harvest action)
+` + "`!coop giftvote <id> <open|leave>`" + ` — Party votes whether to open a gift
+` + "`!coop status`" + ` — Show your current run
+` + "`!coop cancel`" + ` — Cancel an open invite (leader only, before lock)
+
+**How it runs:**
+- 24h invite window. Run locks automatically when window closes.
+- 2-4 players. 2 minimum or invite cancels.
+- Locking the party consumes the day's combat action for every member.
+- Each subsequent day, every player picks a funding tier. Funding modifies
+  the party's per-floor success chance.
+- Inactive players (no funding decision) auto-play at None (-10%).
+- Wipes refund the day's combat action only. Funding is gone.
+- On success, the reward is split evenly. Tax applies.`
+
+// ── Handlers ────────────────────────────────────────────────────────────────
+
+func (p *AdventurePlugin) handleCoopStart(ctx MessageContext, tierArg string) error {
+	tier, err := strconv.Atoi(tierArg)
+	if err != nil || tier < 1 || tier > 5 {
+		return p.SendDM(ctx.Sender, "Tier must be 1-5. Example: `!coop start 3`.")
+	}
+
+	userMu := p.advUserLock(ctx.Sender)
+	userMu.Lock()
+	defer userMu.Unlock()
+
+	char, _, err := p.ensureCharacter(ctx.Sender)
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Failed to load your character.")
+	}
+	if !char.Alive {
+		return p.SendDM(ctx.Sender, "You're dead. Co-op dungeons require a living adventurer.")
+	}
+	if !char.CanDoCombat(false) {
+		return p.SendDM(ctx.Sender, "You've already used your combat action today. Try tomorrow.")
+	}
+
+	// One active run per player.
+	if existing, _ := loadCoopRunForUser(ctx.Sender); existing != nil {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("You're already in a co-op run (#%d, %s). Use `!coop status`.", existing.ID, existing.Status))
+	}
+
+	def := coopTierTable[tier]
+	run, err := createCoopRun(tier, ctx.Sender, def.totalDays, def.baseFailurePct)
+	if err != nil {
+		slog.Error("coop: create run", "err", err)
+		return p.SendDM(ctx.Sender, "Couldn't open an invite. Try again.")
+	}
+	if err := addCoopMember(run.ID, ctx.Sender, 0, char.CombatLevel < def.minLevel); err != nil {
+		slog.Error("coop: add leader", "err", err)
+		return p.SendDM(ctx.Sender, "Couldn't add you to the run.")
+	}
+
+	gr := gamesRoom()
+	if gr != "" {
+		_ = p.SendMessage(gr, renderCoopInvite(run, []CoopMember{{UserID: ctx.Sender, TurnOrder: 0}}, char.DisplayName))
+	}
+	return p.SendDM(ctx.Sender, fmt.Sprintf("⚔️ Tier %d co-op invite opened (#%d). Locks in 24h. Recruit your party.", tier, run.ID))
+}
+
+func (p *AdventurePlugin) handleCoopJoin(ctx MessageContext, runIDArg string) error {
+	userMu := p.advUserLock(ctx.Sender)
+	userMu.Lock()
+	defer userMu.Unlock()
+
+	char, _, err := p.ensureCharacter(ctx.Sender)
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Failed to load your character.")
+	}
+	if !char.Alive {
+		return p.SendDM(ctx.Sender, "You're dead. The dungeon does not accept corpses.")
+	}
+	if !char.CanDoCombat(false) {
+		return p.SendDM(ctx.Sender, "You've already used your combat action today. Try tomorrow.")
+	}
+	if existing, _ := loadCoopRunForUser(ctx.Sender); existing != nil {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("You're already in run #%d.", existing.ID))
+	}
+
+	var run *CoopRun
+	if runIDArg == "" {
+		run, err = loadMostRecentOpenCoopRun()
+	} else {
+		id, perr := strconv.Atoi(runIDArg)
+		if perr != nil {
+			return p.SendDM(ctx.Sender, "Run ID must be a number. Try `!coop join 7` or `!coop join`.")
+		}
+		run, err = loadCoopRun(id)
+	}
+	if err != nil || run == nil {
+		return p.SendDM(ctx.Sender, "No open invite found. Use `!coop list` to see open runs.")
+	}
+	if run.Status != "open" {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("Run #%d is %s. Can't join.", run.ID, run.Status))
+	}
+
+	members, err := loadCoopMembers(run.ID)
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't load the party.")
+	}
+	if len(members) >= coopMaxPartySize {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("Run #%d is full (%d/%d).", run.ID, len(members), coopMaxPartySize))
+	}
+
+	def := coopTierTable[run.Tier]
+	liability := char.CombatLevel < def.minLevel
+	if err := addCoopMember(run.ID, ctx.Sender, len(members), liability); err != nil {
+		slog.Error("coop: join", "err", err)
+		return p.SendDM(ctx.Sender, "Couldn't join.")
+	}
+
+	gr := gamesRoom()
+	if gr != "" {
+		warn := ""
+		if liability {
+			warn = " ⚠️ liability"
+		}
+		_ = p.SendMessage(gr, fmt.Sprintf("⚔️ %s joined Tier %d Co-op #%d (%d/%d)%s.",
+			char.DisplayName, run.Tier, run.ID, len(members)+1, coopMaxPartySize, warn))
+	}
+	return p.SendDM(ctx.Sender, fmt.Sprintf("Joined run #%d. Wait for the lock; the run starts then.", run.ID))
+}
+
+func (p *AdventurePlugin) handleCoopList(ctx MessageContext) error {
+	runs, err := loadOpenCoopRuns()
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't load the list.")
+	}
+	if len(runs) == 0 {
+		return p.SendDM(ctx.Sender, "No open invites right now. Start one with `!coop start <tier>`.")
+	}
+	var sb strings.Builder
+	sb.WriteString("**Open Co-op Invites**\n\n")
+	for _, r := range runs {
+		members, _ := loadCoopMembers(r.ID)
+		closesIn := time.Until(r.CreatedAt.Add(coopInviteWindow)).Truncate(time.Minute)
+		sb.WriteString(fmt.Sprintf("  #%d  T%d (%s)  %d/%d  closes in %s\n",
+			r.ID, r.Tier, coopTierTable[r.Tier].difficulty, len(members), coopMaxPartySize, closesIn))
+	}
+	sb.WriteString("\nJoin with `!coop join <id>` or just `!coop join` for the most recent.")
+	return p.SendDM(ctx.Sender, sb.String())
+}
+
+func (p *AdventurePlugin) handleCoopStatus(ctx MessageContext) error {
+	run, err := loadCoopRunForUser(ctx.Sender)
+	if err != nil || run == nil {
+		return p.SendDM(ctx.Sender, "You're not in a co-op run. Use `!coop list` or `!coop start <tier>`.")
+	}
+	members, _ := loadCoopMembers(run.ID)
+	return p.SendDM(ctx.Sender, renderCoopStatus(p, run, members))
+}
+
+func (p *AdventurePlugin) handleCoopFund(ctx MessageContext, tierArg string) error {
+	tier := parseCoopFundingTier(tierArg)
+	if tier == "" {
+		return p.SendDM(ctx.Sender, "Funding must be one of: none, minimal, standard, aggressive, all_in.")
+	}
+
+	userMu := p.advUserLock(ctx.Sender)
+	userMu.Lock()
+	defer userMu.Unlock()
+
+	run, err := loadCoopRunForUser(ctx.Sender)
+	if err != nil || run == nil {
+		return p.SendDM(ctx.Sender, "You're not in an active co-op run.")
+	}
+	if run.Status != "active" {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("Run #%d is %s — funding decisions don't apply.", run.ID, run.Status))
+	}
+
+	day := run.CurrentDay
+	if day < 1 {
+		return p.SendDM(ctx.Sender, "The run hasn't started yet. Wait for the lock tick.")
+	}
+
+	member, err := loadCoopMember(run.ID, ctx.Sender)
+	if err != nil || member == nil {
+		return p.SendDM(ctx.Sender, "You're not on the party roster for this run.")
+	}
+	if _, alreadySet := member.DailyFunding[day]; alreadySet {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("You've already locked in funding for day %d. Decisions are final until the daily tick.", day))
+	}
+
+	cost := coopFundingTable[tier].cost
+	if cost > 0 {
+		balance := p.euro.GetBalance(ctx.Sender)
+		if balance < float64(cost) {
+			return p.SendDM(ctx.Sender, fmt.Sprintf("That tier costs €%d. You have €%.0f.", cost, balance))
+		}
+		if !p.euro.Debit(ctx.Sender, float64(cost), "coop_funding") {
+			return p.SendDM(ctx.Sender, "Payment failed.")
+		}
+	}
+
+	member.DailyFunding[day] = tier
+	member.TotalContributed += cost
+	if err := saveCoopMemberFunding(member); err != nil {
+		// Refund and surface
+		if cost > 0 {
+			p.euro.Credit(ctx.Sender, float64(cost), "coop_funding_refund")
+		}
+		return p.SendDM(ctx.Sender, "Couldn't save your decision. Gold refunded if any was charged.")
+	}
+	if cost > 0 {
+		if err := addCoopRunPool(run.ID, cost); err != nil {
+			slog.Error("coop: pool update", "err", err)
+		}
+	}
+
+	mod := coopFundingTable[tier].modifier
+	return p.SendDM(ctx.Sender, fmt.Sprintf("Funding for day %d locked: %s (€%d, %+d%%). Tomorrow's tick resolves the floor.",
+		day, coopFundingTable[tier].label, cost, mod))
+}
+
+func (p *AdventurePlugin) handleCoopCancel(ctx MessageContext) error {
+	userMu := p.advUserLock(ctx.Sender)
+	userMu.Lock()
+	defer userMu.Unlock()
+
+	run, err := loadCoopRunForUser(ctx.Sender)
+	if err != nil || run == nil {
+		return p.SendDM(ctx.Sender, "No co-op run to cancel.")
+	}
+	if run.LeaderID != ctx.Sender {
+		return p.SendDM(ctx.Sender, "Only the party leader can cancel.")
+	}
+	if run.Status != "open" {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("Run #%d already %s — too late.", run.ID, run.Status))
+	}
+	if err := setCoopRunStatus(run.ID, "cancelled"); err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't cancel.")
+	}
+	gr := gamesRoom()
+	if gr != "" {
+		_ = p.SendMessage(gr, fmt.Sprintf("⚔️ Tier %d Co-op #%d cancelled by the leader.", run.Tier, run.ID))
+	}
+	return p.SendDM(ctx.Sender, fmt.Sprintf("Run #%d cancelled.", run.ID))
+}
+
+func (p *AdventurePlugin) handleCoopVote(ctx MessageContext, voteArg string) error {
+	userMu := p.advUserLock(ctx.Sender)
+	userMu.Lock()
+	defer userMu.Unlock()
+
+	run, err := loadCoopRunForUser(ctx.Sender)
+	if err != nil || run == nil {
+		return p.SendDM(ctx.Sender, "You're not in an active co-op run.")
+	}
+	if run.Status != "active" {
+		return p.SendDM(ctx.Sender, "No active floor event to vote on.")
+	}
+	event, err := loadCoopEvent(run.ID, run.CurrentDay)
+	if err != nil || event == nil {
+		return p.SendDM(ctx.Sender, "No floor event found for the current day.")
+	}
+	if event.Outcome != "" {
+		return p.SendDM(ctx.Sender, "Voting closed for this floor.")
+	}
+	label, ok := validateCoopVote(event.Category, event.EventIndex, voteArg)
+	if !ok {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("Vote one of: %s.",
+			strings.Join(coopEventOptionLabels(event.Category, event.EventIndex), ", ")))
+	}
+
+	if event.Votes == nil {
+		event.Votes = map[id.UserID]string{}
+	}
+	event.Votes[ctx.Sender] = label
+	if err := saveCoopEventVotes(event); err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't save your vote.")
+	}
+
+	// Update the game-room post in place to show the running tally.
+	gr := gamesRoom()
+	if gr != "" && event.PostEventID != "" {
+		members, _ := loadCoopMembers(run.ID)
+		_ = p.EditMessage(gr, event.PostEventID, renderCoopEventPost(run, members, event))
+	}
+	return p.SendDM(ctx.Sender, fmt.Sprintf("Vote recorded: %s.", label))
+}
+
+// ── Helpers ─────────────────────────────────────────────────────────────────
+
+func parseCoopFundingTier(s string) CoopFundingTier {
+	s = strings.ToLower(strings.TrimSpace(s))
+	s = strings.ReplaceAll(s, "-", "_")
+	s = strings.ReplaceAll(s, " ", "_")
+	switch s {
+	case "none", "skip", "pass":
+		return CoopFundNone
+	case "minimal", "min":
+		return CoopFundMinimal
+	case "standard", "std":
+		return CoopFundStandard
+	case "aggressive", "agg":
+		return CoopFundAggressive
+	case "all_in", "allin", "all":
+		return CoopFundAllIn
+	}
+	return ""
+}
+
+// effectiveModifier returns a member's per-day funding modifier, respecting the
+// liability cap.
+func coopMemberModifier(m *CoopMember, day int) (CoopFundingTier, int) {
+	tier, ok := m.DailyFunding[day]
+	if !ok {
+		tier = CoopFundNone
+	}
+	mod := coopFundingTable[tier].modifier
+	if m.IsLiability && mod > coopLiabilityCap {
+		mod = coopLiabilityCap
+	}
+	return tier, mod
+}
+
+// coopLevelBonus returns the per-floor success bonus from a player's combat
+// level relative to the tier's minimum. Levels above the floor count up
+// (capped); levels below count down. Encourages tier-appropriate parties.
+func coopLevelBonus(combatLevel, tierMinLevel int) int {
+	delta := combatLevel - tierMinLevel
+	bonus := delta * 4 / 10 // 0.4× scale, integer math
+	if bonus > 8 {
+		bonus = 8
+	}
+	if bonus < -8 {
+		bonus = -8
+	}
+	return bonus
+}
+
+// coopPetBonus returns the per-floor success bonus from a player's pet. Worth
+// roughly a quarter of an additional baseline party member at pet level 10.
+// Returns 0 if the player has no pet.
+func coopPetBonus(char *AdventureCharacter) int {
+	if !char.HasPet() || char.PetLevel <= 0 {
+		return 0
+	}
+	bonus := char.PetLevel * 25 / 100 // 0.25× scale
+	if bonus > 2 {
+		bonus = 2
+	}
+	return bonus
+}
diff --git a/internal/plugin/coop_dungeon_balance_test.go b/internal/plugin/coop_dungeon_balance_test.go
new file mode 100644
index 0000000..e91c1b5
--- /dev/null
+++ b/internal/plugin/coop_dungeon_balance_test.go
@@ -0,0 +1,265 @@
+package plugin
+
+import (
+	"fmt"
+	"math/rand/v2"
+	"testing"
+)
+
+// Monte Carlo balance analysis for co-op dungeons.
+//
+// Run with:  go test ./internal/plugin -run TestCoopBalanceReport -v
+// Skipped by default (requires -run filter to invoke); pure-function, no DB.
+
+const (
+	balanceTrials = 50_000
+	balanceTax    = 0.05 // matches coopAdventureRake
+)
+
+type fundingPlan struct {
+	name string
+	// per-player tiers; length = party size
+	tiers []CoopFundingTier
+	// optional fixed per-player level bonus (mimics a profile of avg or
+	// veteran party). 0 = at-minimum (default), positive = stronger party.
+	levelBonusEach int
+	petBonusEach   int
+}
+
+func TestCoopBalanceReport(t *testing.T) {
+	if testing.Short() {
+		t.Skip("balance report skipped in short mode")
+	}
+	t.Parallel()
+
+	rng := rand.New(rand.NewPCG(42, 42))
+
+	profiles := []struct {
+		label       string
+		levelBonus  int
+		petBonus    int
+	}{
+		{"at-minimum (no pets)", 0, 0},
+		{"average (level+5, pet 5)", 2, 1},
+		{"veteran (level+10, pet 10)", 4, 2},
+	}
+
+	for tier := 1; tier <= 5; tier++ {
+		def := coopTierTable[tier]
+		fmt.Printf("\n══ Tier %d (%s) — %d days, base failure %d%%/floor, reward €%d ══\n",
+			tier, def.difficulty, def.totalDays, def.baseFailurePct, def.rewardBase)
+
+		for _, prof := range profiles {
+			fmt.Printf("\n  Party profile: %s\n", prof.label)
+			fmt.Printf("  %-28s %-10s %-12s %-12s %-12s %-12s\n",
+				"strategy", "P(win)", "E[reward]", "E[funding]", "E[net]", "E[net/day]")
+			for _, plan := range balancePlans() {
+				plan.levelBonusEach = prof.levelBonus
+				plan.petBonusEach = prof.petBonus
+				pSuccess, eReward, eCost, eNet := simulatePlan(rng, tier, def, plan)
+				perDay := eNet / float64(def.totalDays)
+				fmt.Printf("  %-28s %-10.3f €%-11.0f €%-11.0f €%-11.0f €%-11.0f\n",
+					plan.name, pSuccess, eReward, eCost, eNet, perDay)
+			}
+		}
+	}
+	fmt.Println()
+	fmt.Println("Note: E[net] is per-player. Funding is non-refundable. Combat-action opportunity cost not included.")
+}
+
+func anyNoneFunder(plan fundingPlan) bool {
+	for _, t := range plan.tiers {
+		if t == CoopFundNone {
+			return true
+		}
+	}
+	return false
+}
+
+// balancePlans returns a representative set of party funding strategies.
+// Party size = 4 unless name says otherwise.
+func balancePlans() []fundingPlan {
+	mk := func(n int, t CoopFundingTier) []CoopFundingTier {
+		out := make([]CoopFundingTier, n)
+		for i := range out {
+			out[i] = t
+		}
+		return out
+	}
+	return []fundingPlan{
+		{name: "4× Minimal", tiers: mk(4, CoopFundMinimal)},
+		{name: "4× Standard", tiers: mk(4, CoopFundStandard)},
+		{name: "4× Aggressive", tiers: mk(4, CoopFundAggressive)},
+		{name: "4× All-In", tiers: mk(4, CoopFundAllIn)},
+		{name: "4× mixed (2 Std, 2 Agg)", tiers: []CoopFundingTier{CoopFundStandard, CoopFundStandard, CoopFundAggressive, CoopFundAggressive}},
+		{name: "4× sandbag (3 Std, 1 None)", tiers: []CoopFundingTier{CoopFundStandard, CoopFundStandard, CoopFundStandard, CoopFundNone}},
+		{name: "3× Standard", tiers: mk(3, CoopFundStandard)},
+		{name: "3× Aggressive", tiers: mk(3, CoopFundAggressive)},
+		{name: "2× Standard", tiers: mk(2, CoopFundStandard)},
+		{name: "2× Aggressive", tiers: mk(2, CoopFundAggressive)},
+		{name: "2× All-In", tiers: mk(2, CoopFundAllIn)},
+	}
+}
+
+// simulatePlan runs the trials and returns:
+//
+//	P(success), E[reward share post-tax], E[funding spent per player], E[net per player]
+//
+// Funding is paid every day regardless of wipe. Reward is split evenly across
+// the party on success only. Per-player figures average the contribution across
+// the actual party members under the plan.
+func simulatePlan(rng *rand.Rand, tier int, def coopTierDef, plan fundingPlan) (float64, float64, float64, float64) {
+	partySize := len(plan.tiers)
+	if partySize < coopMinPartySize {
+		return 0, 0, 0, 0
+	}
+
+	// Compute per-floor success% under this plan (deterministic given plan).
+	totalMod := 0
+	for _, t := range plan.tiers {
+		totalMod += coopFundingTable[t].modifier
+	}
+	// Per-player level + pet bonuses applied across the whole party.
+	totalMod += partySize * (plan.levelBonusEach + plan.petBonusEach)
+	successPct := 100 - def.baseFailurePct + totalMod
+	if successPct < 5 {
+		successPct = 5
+	}
+	if successPct > 95 {
+		successPct = 95
+	}
+
+	wins := 0
+	for trial := 0; trial < balanceTrials; trial++ {
+		runWon := true
+		for floor := 0; floor < def.totalDays; floor++ {
+			if rng.IntN(100) >= successPct {
+				runWon = false
+				break
+			}
+		}
+		if runWon {
+			wins++
+		}
+	}
+	pWin := float64(wins) / float64(balanceTrials)
+
+	// Average per-player numbers across the party. Funding cost = daily cost × days,
+	// paid regardless of outcome. Reward = share post-tax × P(win).
+	var sumCost, sumReward float64
+	share := float64(def.rewardBase) / float64(partySize)
+	postTaxShare := share * (1 - balanceTax)
+	for _, t := range plan.tiers {
+		dailyCost := float64(coopFundingTable[t].cost)
+		sumCost += dailyCost * float64(def.totalDays)
+		sumReward += postTaxShare * pWin
+	}
+	avgCost := sumCost / float64(partySize)
+	avgReward := sumReward / float64(partySize)
+	avgNet := avgReward - avgCost
+	return pWin, avgReward, avgCost, avgNet
+}
+
+// TestSoloVsCoopDailyIncome compares expected gold-per-day for a competent
+// solo dungeon grinder vs a co-op party member at the optimal funding strategy.
+// Co-op should be meaningfully more rewarding per day than solo.
+//
+// Solo model: a "competent" player whose skill matches the location's MinLevel
+// and gear matches MinEquipTier. Uses the actual loot tables from
+// adventure_activities.go.
+func TestSoloVsCoopDailyIncome(t *testing.T) {
+	if testing.Short() {
+		t.Skip()
+	}
+
+	// Per-tier solo expected income (avg item value × items-per-haul, weighted
+	// by outcome probabilities, after 5% community tax, minus a rough death
+	// cost that captures gear repair + hospital).
+	type soloPerTier struct {
+		successPct, exceptionalPct, deathPct float64
+		successHaul, exceptionalHaul         float64
+		deathCost                            float64
+	}
+	// Probabilities computed from calculateAdvProbabilities() with skill =
+	// MinLevel and eqScore matching MinEquipTier (rough but consistent).
+	// Death costs assume hospital insurance + lower blacksmith repair rates.
+	solo := map[int]soloPerTier{
+		1: {0.74, 0.10, 0.01, 11.6, 29.0, 100},
+		2: {0.67, 0.10, 0.08, 63.75, 159.0, 400},
+		3: {0.60, 0.10, 0.18, 337.5, 844.0, 1200},
+		4: {0.55, 0.08, 0.21, 1700.0, 4250.0, 3000},
+		5: {0.61, 0.08, 0.20, 9500.0, 23750.0, 6000},
+	}
+	soloDaily := func(s soloPerTier) float64 {
+		gross := s.successPct*s.successHaul + s.exceptionalPct*s.exceptionalHaul
+		afterTax := gross * (1 - balanceTax)
+		return afterTax - s.deathPct*s.deathCost
+	}
+
+	rng := rand.New(rand.NewPCG(7, 7))
+
+	fmt.Println("\nSolo dungeon vs co-op (€/day per player at optimal funding strategy):")
+	fmt.Printf("%-6s %-14s %-26s %-14s %-10s\n", "tier", "solo €/day", "co-op optimal", "co-op €/day", "ratio")
+	for tier := 1; tier <= 5; tier++ {
+		def := coopTierTable[tier]
+		soloIncome := soloDaily(solo[tier])
+
+		// Find best 4-player plan by E[net]/day, assuming an "average" party
+		// profile (levelBonus=2, petBonus=1 per player). Restricting to
+		// 4-player keeps the comparison apples-to-apples.
+		var bestPlan fundingPlan
+		bestPerDay := -1.0e18
+		for _, plan := range balancePlans() {
+			if len(plan.tiers) != 4 {
+				continue
+			}
+			// Skip free-rider plans: an "optimal" that only works because
+			// one member contributes nothing isn't a coordinated strategy.
+			if anyNoneFunder(plan) {
+				continue
+			}
+			plan.levelBonusEach = 2
+			plan.petBonusEach = 1
+			_, _, _, eNet := simulatePlan(rng, tier, def, plan)
+			perDay := eNet / float64(def.totalDays)
+			if perDay > bestPerDay {
+				bestPerDay = perDay
+				bestPlan = plan
+			}
+		}
+		ratio := bestPerDay / soloIncome
+		flag := "✓"
+		if ratio < 1.5 {
+			flag = "⚠ insufficient"
+		}
+		fmt.Printf("T%-5d €%-13.0f %-26s €%-13.0f %.2fx %s\n",
+			tier, soloIncome, bestPlan.name, bestPerDay, ratio, flag)
+	}
+	fmt.Println("\n⚠ marker = co-op fails the 1.5× solo threshold; bump rewardBase.")
+}
+
+// TestCoopBalanceSweep prints, for each tier, the success% needed for E[net]>=0
+// at common funding levels. Helps spot tiers where the formula is upside-down.
+func TestCoopBalanceSweep(t *testing.T) {
+	if testing.Short() {
+		t.Skip()
+	}
+	fmt.Println("\nBreakeven analysis — minimum P(win) for E[net]≥0 per player at party size 4:")
+	fmt.Printf("%-12s %-12s %-12s %-12s %-12s\n", "tier", "Minimal", "Standard", "Aggressive", "All-In")
+	for tier := 1; tier <= 5; tier++ {
+		def := coopTierTable[tier]
+		share := float64(def.rewardBase) / 4.0 * (1 - balanceTax)
+		row := []string{}
+		for _, ft := range []CoopFundingTier{CoopFundMinimal, CoopFundStandard, CoopFundAggressive, CoopFundAllIn} {
+			cost := float64(coopFundingTable[ft].cost) * float64(def.totalDays)
+			breakeven := cost / share
+			if breakeven > 1 {
+				row = append(row, ">100% (impossible)")
+			} else {
+				row = append(row, fmt.Sprintf("%.1f%%", breakeven*100))
+			}
+		}
+		fmt.Printf("T%-11d %-12s %-12s %-12s %-12s\n", tier, row[0], row[1], row[2], row[3])
+	}
+	fmt.Println()
+}
diff --git a/internal/plugin/coop_dungeon_betting.go b/internal/plugin/coop_dungeon_betting.go
new file mode 100644
index 0000000..86b76c9
--- /dev/null
+++ b/internal/plugin/coop_dungeon_betting.go
@@ -0,0 +1,323 @@
+package plugin
+
+import (
+	"database/sql"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// ── Betting Constants ───────────────────────────────────────────────────────
+
+const (
+	coopBetMin      = 100
+	coopBetMax      = 1_000_000
+	coopBetRake     = 0.10 // 10% house cut, per spec
+	coopOddsWindow  = 30   // helpfulness rolling-window size
+	coopOddsHelpInf = 0.20 // helpfulness contribution to estimated success
+)
+
+// ── Bet Types ───────────────────────────────────────────────────────────────
+
+type CoopBet struct {
+	RunID    int
+	PlayerID id.UserID
+	Position string // "success" | "failure"
+	Amount   int
+	Payout   sql.NullInt64
+}
+
+// ── Command Handler ─────────────────────────────────────────────────────────
+
+func (p *AdventurePlugin) handleCoopBet(ctx MessageContext, args string) error {
+	parts := strings.Fields(args)
+	if len(parts) < 2 {
+		return p.SendDM(ctx.Sender, "Usage: `!coop bet <run_id> <amount> <success|failure>` or `!coop bet <amount> <success|failure>` for the most recent open/active run.")
+	}
+
+	// Two forms: with or without explicit run id.
+	var runID, amount int
+	var position string
+	var err error
+
+	if len(parts) >= 3 {
+		runID, err = strconv.Atoi(parts[0])
+		if err != nil {
+			return p.SendDM(ctx.Sender, "First arg must be the run id.")
+		}
+		amount, err = strconv.Atoi(parts[1])
+		if err != nil {
+			return p.SendDM(ctx.Sender, "Amount must be a number.")
+		}
+		position = strings.ToLower(parts[2])
+	} else {
+		amount, err = strconv.Atoi(parts[0])
+		if err != nil {
+			return p.SendDM(ctx.Sender, "Amount must be a number.")
+		}
+		position = strings.ToLower(parts[1])
+		run, _ := loadMostRecentBettableCoopRun()
+		if run == nil {
+			return p.SendDM(ctx.Sender, "No co-op runs accept bets right now.")
+		}
+		runID = run.ID
+	}
+
+	if position != "success" && position != "failure" {
+		return p.SendDM(ctx.Sender, "Position must be `success` or `failure`.")
+	}
+	if amount < coopBetMin || amount > coopBetMax {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("Bet must be between €%d and €%d.", coopBetMin, coopBetMax))
+	}
+
+	run, err := loadCoopRun(runID)
+	if err != nil || run == nil {
+		return p.SendDM(ctx.Sender, "Run not found.")
+	}
+	if run.Status != "open" && run.Status != "active" {
+		return p.SendDM(ctx.Sender, "Bets are closed on this run.")
+	}
+
+	balance := p.euro.GetBalance(ctx.Sender)
+	if balance < float64(amount) {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("You have €%.0f. Bet was €%d.", balance, amount))
+	}
+
+	existing, _ := loadCoopBet(runID, ctx.Sender)
+	if existing != nil && existing.Position != position {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("You already bet %s on this run. Positions can't be switched.", existing.Position))
+	}
+
+	if !p.euro.Debit(ctx.Sender, float64(amount), "coop_bet") {
+		return p.SendDM(ctx.Sender, "Payment failed.")
+	}
+
+	if existing == nil {
+		err = createCoopBet(runID, ctx.Sender, position, amount)
+	} else {
+		err = increaseCoopBet(runID, ctx.Sender, amount)
+	}
+	if err != nil {
+		p.euro.Credit(ctx.Sender, float64(amount), "coop_bet_refund")
+		return p.SendDM(ctx.Sender, "Couldn't save bet. Refunded.")
+	}
+
+	total := amount
+	if existing != nil {
+		total += existing.Amount
+	}
+	return p.SendDM(ctx.Sender, fmt.Sprintf("📊 Bet placed: €%d on %s (run #%d). Total stake: €%d.",
+		amount, position, runID, total))
+}
+
+// ── Odds Calculation ────────────────────────────────────────────────────────
+
+// coopEstimatedRunSuccess returns the estimated P(success) for the rest of the
+// run given current party state. Used for spectator odds display.
+func coopEstimatedRunSuccess(run *CoopRun, members []CoopMember) float64 {
+	if run.Status != "open" && run.Status != "active" {
+		return 0
+	}
+	if len(members) == 0 {
+		return 0
+	}
+	tierDef := coopTierTable[run.Tier]
+
+	// Per-floor success at "Standard" funding by all members (a neutral
+	// baseline — actual funding varies day to day).
+	mod := len(members) * coopFundingTable[CoopFundStandard].modifier
+	for _, m := range members {
+		char, err := loadAdvCharacter(m.UserID)
+		if err != nil {
+			continue
+		}
+		mod += coopLevelBonus(char.CombatLevel, tierDef.minLevel)
+		mod += coopPetBonus(char)
+	}
+	successPct := 100 - run.BaseDifficulty + mod
+
+	// TwinBee helpfulness shifts the line: a "helpful" history (close to 1)
+	// bumps odds; an "unhelpful" history pulls them down.
+	help := coopTwinBeeHelpfulness(coopOddsWindow)
+	successPct += int(math.Round((help - 0.5) * 2 * coopOddsHelpInf * 100))
+
+	if successPct < 5 {
+		successPct = 5
+	}
+	if successPct > 95 {
+		successPct = 95
+	}
+
+	floorsRemaining := run.TotalDays - run.CurrentDay
+	if floorsRemaining < 0 {
+		floorsRemaining = 0
+	}
+	if run.Status == "open" {
+		floorsRemaining = run.TotalDays
+	}
+
+	return math.Pow(float64(successPct)/100.0, float64(floorsRemaining))
+}
+
+// coopParimutuelPayouts returns winning side, losers' side, rake, and
+// per-player payout map (winning bettors only).
+func coopParimutuelPayouts(bets []CoopBet, winningPosition string) (winners []CoopBet, totalPool, rake int, payouts map[id.UserID]int) {
+	for _, b := range bets {
+		totalPool += b.Amount
+	}
+	rake = int(math.Floor(float64(totalPool) * coopBetRake))
+	netPool := totalPool - rake
+
+	winningPool := 0
+	for _, b := range bets {
+		if b.Position == winningPosition {
+			winners = append(winners, b)
+			winningPool += b.Amount
+		}
+	}
+
+	payouts = map[id.UserID]int{}
+	if winningPool == 0 {
+		// No winners — house keeps everything (this happens if e.g. all bets
+		// were on the wrong side).
+		return
+	}
+	for _, b := range winners {
+		share := float64(b.Amount) / float64(winningPool)
+		payouts[b.PlayerID] = int(math.Floor(share * float64(netPool)))
+	}
+	return
+}
+
+// ── DB ──────────────────────────────────────────────────────────────────────
+
+func createCoopBet(runID int, userID id.UserID, position string, amount int) error {
+	d := db.Get()
+	_, err := d.Exec(`INSERT INTO coop_dungeon_bets (run_id, player_id, position, amount)
+		VALUES (?, ?, ?, ?)`, runID, string(userID), position, amount)
+	return err
+}
+
+func increaseCoopBet(runID int, userID id.UserID, delta int) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_bets SET amount = amount + ?
+		WHERE run_id = ? AND player_id = ?`, delta, runID, string(userID))
+	return err
+}
+
+func loadCoopBet(runID int, userID id.UserID) (*CoopBet, error) {
+	d := db.Get()
+	b := &CoopBet{}
+	var uid string
+	err := d.QueryRow(`SELECT run_id, player_id, position, amount, payout
+		FROM coop_dungeon_bets WHERE run_id = ? AND player_id = ?`, runID, string(userID)).Scan(
+		&b.RunID, &uid, &b.Position, &b.Amount, &b.Payout)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	b.PlayerID = id.UserID(uid)
+	return b, nil
+}
+
+func loadCoopBets(runID int) ([]CoopBet, error) {
+	d := db.Get()
+	rows, err := d.Query(`SELECT run_id, player_id, position, amount, payout
+		FROM coop_dungeon_bets WHERE run_id = ?`, runID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []CoopBet
+	for rows.Next() {
+		b := CoopBet{}
+		var uid string
+		if err := rows.Scan(&b.RunID, &uid, &b.Position, &b.Amount, &b.Payout); err != nil {
+			return nil, err
+		}
+		b.PlayerID = id.UserID(uid)
+		out = append(out, b)
+	}
+	return out, rows.Err()
+}
+
+func setCoopBetPayout(runID int, userID id.UserID, payout int) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_bets SET payout = ?
+		WHERE run_id = ? AND player_id = ?`, payout, runID, string(userID))
+	return err
+}
+
+func loadMostRecentBettableCoopRun() (*CoopRun, error) {
+	runs, err := queryCoopRuns(`status IN ('open','active') ORDER BY id DESC LIMIT 1`)
+	if err != nil || len(runs) == 0 {
+		return nil, err
+	}
+	return runs[0], nil
+}
+
+// ── Resolution ──────────────────────────────────────────────────────────────
+
+// coopResolveBets is called when a run completes. It computes payouts,
+// credits winners, persists payout values, and posts a summary line.
+func (p *AdventurePlugin) coopResolveBets(run *CoopRun, won bool) string {
+	bets, err := loadCoopBets(run.ID)
+	if err != nil || len(bets) == 0 {
+		return ""
+	}
+	winningPosition := "failure"
+	if won {
+		winningPosition = "success"
+	}
+	winners, total, rake, payouts := coopParimutuelPayouts(bets, winningPosition)
+
+	for _, b := range winners {
+		payout := payouts[b.PlayerID]
+		if payout > 0 {
+			p.euro.Credit(b.PlayerID, float64(payout), "coop_bet_payout")
+		}
+		_ = setCoopBetPayout(run.ID, b.PlayerID, payout)
+	}
+	for _, b := range bets {
+		if b.Position != winningPosition {
+			_ = setCoopBetPayout(run.ID, b.PlayerID, 0)
+		}
+	}
+
+	if len(winners) == 0 {
+		return fmt.Sprintf("📊 Parimutuel pool: €%d. No winners — house (TwinBee) keeps the pool.", total)
+	}
+
+	var sb strings.Builder
+	sb.WriteString(fmt.Sprintf("📊 Parimutuel pool: €%d. Rake: €%d. Net: €%d.\n", total, rake, total-rake))
+	sb.WriteString(fmt.Sprintf("Winners (bet on %s):\n", winningPosition))
+	for _, b := range winners {
+		sb.WriteString(fmt.Sprintf("  %s: €%d → €%d\n", coopDisplayName(p, b.PlayerID), b.Amount, payouts[b.PlayerID]))
+	}
+	return sb.String()
+}
+
+// ── Render ──────────────────────────────────────────────────────────────────
+
+func renderCoopOddsLine(run *CoopRun, members []CoopMember, bets []CoopBet) string {
+	pSuccess := coopEstimatedRunSuccess(run, members)
+	successPool, failurePool := 0, 0
+	for _, b := range bets {
+		if b.Position == "success" {
+			successPool += b.Amount
+		} else {
+			failurePool += b.Amount
+		}
+	}
+	total := successPool + failurePool
+	return fmt.Sprintf("📊 Estimated success: %.0f%%. Pool €%d (success €%d / failure €%d). Rake %.0f%%. `!coop bet <amount> success|failure`.",
+		pSuccess*100, total, successPool, failurePool, coopBetRake*100)
+}
+
diff --git a/internal/plugin/coop_dungeon_db.go b/internal/plugin/coop_dungeon_db.go
new file mode 100644
index 0000000..4ecbb27
--- /dev/null
+++ b/internal/plugin/coop_dungeon_db.go
@@ -0,0 +1,407 @@
+package plugin
+
+import (
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"time"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
+)
+
+type CoopRun struct {
+	ID             int
+	Tier           int
+	Status         string
+	LeaderID       id.UserID
+	CurrentDay     int
+	TotalDays      int
+	BaseDifficulty int
+	GoldPool       int
+	RewardTotal    int
+	CreatedAt      time.Time
+	LockedAt       *time.Time
+	CompletedAt    *time.Time
+}
+
+type CoopMember struct {
+	RunID            int
+	UserID           id.UserID
+	TurnOrder        int
+	TotalContributed int
+	IsLiability      bool
+	DailyFunding     map[int]CoopFundingTier // day → tier
+}
+
+func createCoopRun(tier int, leader id.UserID, totalDays, baseDifficulty int) (*CoopRun, error) {
+	d := db.Get()
+	res, err := d.Exec(`INSERT INTO coop_dungeon_runs (tier, leader_id, total_days, base_difficulty)
+		VALUES (?, ?, ?, ?)`, tier, string(leader), totalDays, baseDifficulty)
+	if err != nil {
+		return nil, err
+	}
+	id64, _ := res.LastInsertId()
+	return loadCoopRun(int(id64))
+}
+
+func loadCoopRun(runID int) (*CoopRun, error) {
+	d := db.Get()
+	r := &CoopRun{}
+	var leader string
+	var lockedAt, completedAt sql.NullTime
+	err := d.QueryRow(`SELECT id, tier, status, leader_id, current_day, total_days,
+		base_difficulty, gold_pool, reward_total, created_at, locked_at, completed_at
+		FROM coop_dungeon_runs WHERE id = ?`, runID).Scan(
+		&r.ID, &r.Tier, &r.Status, &leader, &r.CurrentDay, &r.TotalDays,
+		&r.BaseDifficulty, &r.GoldPool, &r.RewardTotal,
+		&r.CreatedAt, &lockedAt, &completedAt)
+	if err != nil {
+		return nil, err
+	}
+	r.LeaderID = id.UserID(leader)
+	if lockedAt.Valid {
+		t := lockedAt.Time
+		r.LockedAt = &t
+	}
+	if completedAt.Valid {
+		t := completedAt.Time
+		r.CompletedAt = &t
+	}
+	return r, nil
+}
+
+func loadOpenCoopRuns() ([]*CoopRun, error) {
+	return queryCoopRuns(`status = 'open' ORDER BY created_at DESC`)
+}
+
+func loadActiveCoopRuns() ([]*CoopRun, error) {
+	return queryCoopRuns(`status = 'active' ORDER BY id`)
+}
+
+func loadMostRecentOpenCoopRun() (*CoopRun, error) {
+	runs, err := queryCoopRuns(`status = 'open' ORDER BY created_at DESC LIMIT 1`)
+	if err != nil || len(runs) == 0 {
+		return nil, err
+	}
+	return runs[0], nil
+}
+
+func queryCoopRuns(whereClause string) ([]*CoopRun, error) {
+	d := db.Get()
+	rows, err := d.Query(`SELECT id, tier, status, leader_id, current_day, total_days,
+		base_difficulty, gold_pool, reward_total, created_at, locked_at, completed_at
+		FROM coop_dungeon_runs WHERE ` + whereClause)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var out []*CoopRun
+	for rows.Next() {
+		r := &CoopRun{}
+		var leader string
+		var lockedAt, completedAt sql.NullTime
+		if err := rows.Scan(&r.ID, &r.Tier, &r.Status, &leader, &r.CurrentDay, &r.TotalDays,
+			&r.BaseDifficulty, &r.GoldPool, &r.RewardTotal,
+			&r.CreatedAt, &lockedAt, &completedAt); err != nil {
+			return nil, err
+		}
+		r.LeaderID = id.UserID(leader)
+		if lockedAt.Valid {
+			t := lockedAt.Time
+			r.LockedAt = &t
+		}
+		if completedAt.Valid {
+			t := completedAt.Time
+			r.CompletedAt = &t
+		}
+		out = append(out, r)
+	}
+	return out, rows.Err()
+}
+
+func loadCoopRunForUser(userID id.UserID) (*CoopRun, error) {
+	d := db.Get()
+	var runID int
+	err := d.QueryRow(`SELECT m.run_id FROM coop_dungeon_members m
+		JOIN coop_dungeon_runs r ON r.id = m.run_id
+		WHERE m.user_id = ? AND r.status IN ('open','active')
+		ORDER BY r.id DESC LIMIT 1`, string(userID)).Scan(&runID)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return loadCoopRun(runID)
+}
+
+func setCoopRunStatus(runID int, status string) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_runs SET status = ? WHERE id = ?`, status, runID)
+	return err
+}
+
+func lockCoopRun(runID int) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_runs
+		SET status = 'active', locked_at = CURRENT_TIMESTAMP, current_day = 1
+		WHERE id = ? AND status = 'open'`, runID)
+	return err
+}
+
+func advanceCoopDay(runID, newDay int) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_runs SET current_day = ? WHERE id = ?`, newDay, runID)
+	return err
+}
+
+func completeCoopRun(runID int, status string, reward int) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_runs
+		SET status = ?, reward_total = ?, completed_at = CURRENT_TIMESTAMP
+		WHERE id = ?`, status, reward, runID)
+	return err
+}
+
+func addCoopRunPool(runID, delta int) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_runs SET gold_pool = gold_pool + ? WHERE id = ?`, delta, runID)
+	return err
+}
+
+// ── Members ─────────────────────────────────────────────────────────────────
+
+func addCoopMember(runID int, userID id.UserID, turnOrder int, liability bool) error {
+	d := db.Get()
+	libVal := 0
+	if liability {
+		libVal = 1
+	}
+	_, err := d.Exec(`INSERT INTO coop_dungeon_members
+		(run_id, user_id, turn_order, is_liability, daily_funding) VALUES (?, ?, ?, ?, '{}')`,
+		runID, string(userID), turnOrder, libVal)
+	return err
+}
+
+func loadCoopMembers(runID int) ([]CoopMember, error) {
+	d := db.Get()
+	rows, err := d.Query(`SELECT run_id, user_id, turn_order, total_contributed, is_liability, daily_funding
+		FROM coop_dungeon_members WHERE run_id = ? ORDER BY turn_order`, runID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var out []CoopMember
+	for rows.Next() {
+		m := CoopMember{}
+		var userID, fundingJSON string
+		var liability int
+		if err := rows.Scan(&m.RunID, &userID, &m.TurnOrder, &m.TotalContributed, &liability, &fundingJSON); err != nil {
+			return nil, err
+		}
+		m.UserID = id.UserID(userID)
+		m.IsLiability = liability != 0
+		m.DailyFunding = parseCoopFundingMap(fundingJSON)
+		out = append(out, m)
+	}
+	return out, rows.Err()
+}
+
+func loadCoopMember(runID int, userID id.UserID) (*CoopMember, error) {
+	d := db.Get()
+	m := &CoopMember{}
+	var uid, fundingJSON string
+	var liability int
+	err := d.QueryRow(`SELECT run_id, user_id, turn_order, total_contributed, is_liability, daily_funding
+		FROM coop_dungeon_members WHERE run_id = ? AND user_id = ?`, runID, string(userID)).Scan(
+		&m.RunID, &uid, &m.TurnOrder, &m.TotalContributed, &liability, &fundingJSON)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	m.UserID = id.UserID(uid)
+	m.IsLiability = liability != 0
+	m.DailyFunding = parseCoopFundingMap(fundingJSON)
+	return m, nil
+}
+
+func saveCoopMemberFunding(m *CoopMember) error {
+	d := db.Get()
+	jsonBytes, err := json.Marshal(serializeCoopFundingMap(m.DailyFunding))
+	if err != nil {
+		return err
+	}
+	_, err = d.Exec(`UPDATE coop_dungeon_members
+		SET daily_funding = ?, total_contributed = ?
+		WHERE run_id = ? AND user_id = ?`,
+		string(jsonBytes), m.TotalContributed, m.RunID, string(m.UserID))
+	return err
+}
+
+func parseCoopFundingMap(s string) map[int]CoopFundingTier {
+	out := map[int]CoopFundingTier{}
+	if s == "" || s == "{}" {
+		return out
+	}
+	raw := map[string]string{}
+	if err := json.Unmarshal([]byte(s), &raw); err != nil {
+		return out
+	}
+	for k, v := range raw {
+		day, err := strconv.Atoi(k)
+		if err != nil {
+			continue
+		}
+		out[day] = CoopFundingTier(v)
+	}
+	return out
+}
+
+func serializeCoopFundingMap(m map[int]CoopFundingTier) map[string]string {
+	out := make(map[string]string, len(m))
+	for k, v := range m {
+		out[fmt.Sprintf("%d", k)] = string(v)
+	}
+	return out
+}
+
+// ── Floor Events ────────────────────────────────────────────────────────────
+
+type CoopEvent struct {
+	RunID           int
+	Day             int
+	Category        CoopEventCategory
+	EventIndex      int
+	Recommended     string
+	Votes           map[id.UserID]string // userID → option label
+	WinningVote     string               // "" until resolved
+	Outcome         string               // "" until resolved; "success" or "failure"
+	ModifierApplied int
+	PostEventID     id.EventID
+}
+
+func createCoopEvent(runID, day int, cat CoopEventCategory, idx int, recommended string) error {
+	d := db.Get()
+	_, err := d.Exec(`INSERT INTO coop_dungeon_events
+		(run_id, day, category, event_index, recommended) VALUES (?, ?, ?, ?, ?)`,
+		runID, day, string(cat), idx, recommended)
+	return err
+}
+
+func loadCoopEvent(runID, day int) (*CoopEvent, error) {
+	d := db.Get()
+	e := &CoopEvent{}
+	var cat, votesJSON string
+	var winning, outcome, postID sql.NullString
+	err := d.QueryRow(`SELECT run_id, day, category, event_index, recommended,
+		votes, winning_vote, outcome, modifier_applied, post_event_id
+		FROM coop_dungeon_events WHERE run_id = ? AND day = ?`, runID, day).Scan(
+		&e.RunID, &e.Day, &cat, &e.EventIndex, &e.Recommended,
+		&votesJSON, &winning, &outcome, &e.ModifierApplied, &postID)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	e.Category = CoopEventCategory(cat)
+	e.Votes = parseCoopVotes(votesJSON)
+	if winning.Valid {
+		e.WinningVote = winning.String
+	}
+	if outcome.Valid {
+		e.Outcome = outcome.String
+	}
+	if postID.Valid {
+		e.PostEventID = id.EventID(postID.String)
+	}
+	return e, nil
+}
+
+func saveCoopEventVotes(e *CoopEvent) error {
+	d := db.Get()
+	jsonBytes, err := json.Marshal(serializeCoopVotes(e.Votes))
+	if err != nil {
+		return err
+	}
+	_, err = d.Exec(`UPDATE coop_dungeon_events SET votes = ?
+		WHERE run_id = ? AND day = ?`, string(jsonBytes), e.RunID, e.Day)
+	return err
+}
+
+func saveCoopEventPostID(runID, day int, eventID id.EventID) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_events SET post_event_id = ?
+		WHERE run_id = ? AND day = ?`, string(eventID), runID, day)
+	return err
+}
+
+func resolveCoopEvent(runID, day int, winning, outcome string, modifier int) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_events
+		SET winning_vote = ?, outcome = ?, modifier_applied = ?
+		WHERE run_id = ? AND day = ?`, winning, outcome, modifier, runID, day)
+	return err
+}
+
+// CoopTwinBeeHelpfulness returns a score in [0,1] where 1 means TwinBee's
+// recommendations have been winning + succeeding (or losing + failing). Used
+// by phase 3 betting odds.
+func coopTwinBeeHelpfulness(window int) float64 {
+	d := db.Get()
+	rows, err := d.Query(`SELECT recommended, winning_vote, outcome
+		FROM coop_dungeon_events
+		WHERE outcome IS NOT NULL
+		ORDER BY rowid DESC LIMIT ?`, window)
+	if err != nil {
+		return 0.5
+	}
+	defer rows.Close()
+	hits, total := 0, 0
+	for rows.Next() {
+		var rec, win, out string
+		if err := rows.Scan(&rec, &win, &out); err != nil {
+			continue
+		}
+		total++
+		if rec == win && out == "success" {
+			hits++
+		} else if rec != win && out == "failure" {
+			hits++
+		}
+	}
+	if total == 0 {
+		return 0.5
+	}
+	return float64(hits) / float64(total)
+}
+
+func parseCoopVotes(s string) map[id.UserID]string {
+	out := map[id.UserID]string{}
+	if s == "" || s == "{}" {
+		return out
+	}
+	raw := map[string]string{}
+	if err := json.Unmarshal([]byte(s), &raw); err != nil {
+		return out
+	}
+	for k, v := range raw {
+		out[id.UserID(k)] = v
+	}
+	return out
+}
+
+func serializeCoopVotes(m map[id.UserID]string) map[string]string {
+	out := make(map[string]string, len(m))
+	for k, v := range m {
+		out[string(k)] = v
+	}
+	return out
+}
diff --git a/internal/plugin/coop_dungeon_gifts.go b/internal/plugin/coop_dungeon_gifts.go
new file mode 100644
index 0000000..9a37fe7
--- /dev/null
+++ b/internal/plugin/coop_dungeon_gifts.go
@@ -0,0 +1,476 @@
+package plugin
+
+import (
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"math/rand/v2"
+	"strconv"
+	"strings"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// ── Gift Constants ──────────────────────────────────────────────────────────
+//
+// Modifiers chosen so the EV of "always open" vs "always leave" is symmetric
+// at a 50/50 sender mix — the party has to read the context, not the math.
+//
+//   basket opened:    +7        basket unopened:  -4
+//   mimic opened:     -7        mimic unopened:   +4
+//
+// At 50/50 sender mix:
+//   always open  EV = 0.5×(+7) + 0.5×(−7) = 0
+//   always leave EV = 0.5×(−4) + 0.5×(+4) = 0
+
+const (
+	coopGiftBasketOpened   = 7
+	coopGiftBasketUnopened = -4
+	coopGiftMimicOpened    = -7
+	coopGiftMimicUnopened  = 4
+)
+
+const (
+	coopGiftBasket = "basket"
+	coopGiftMimic  = "mimic"
+)
+
+type CoopGift struct {
+	ID            int
+	RunID         int
+	SenderID      id.UserID
+	Day           int
+	GiftType      string
+	Votes         map[id.UserID]string // "open" or "leave"
+	VoteResult    string               // "opened" / "left" / ""
+	Outcome       string               // "boost" / "reduction" / ""
+	Modifier      int
+	PostEventID   id.EventID
+}
+
+// ── Command: send a gift ────────────────────────────────────────────────────
+
+func (p *AdventurePlugin) handleCoopGift(ctx MessageContext, args string) error {
+	parts := strings.Fields(args)
+	if len(parts) < 2 {
+		return p.SendDM(ctx.Sender, "Usage: `!coop gift <run_id> <basket|mimic>`. Costs one harvest action; party never knows what you sent.")
+	}
+	runID, err := strconv.Atoi(parts[0])
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Run ID must be a number.")
+	}
+	giftType := strings.ToLower(parts[1])
+	if giftType != coopGiftBasket && giftType != coopGiftMimic {
+		return p.SendDM(ctx.Sender, "Gift type must be `basket` or `mimic`.")
+	}
+
+	userMu := p.advUserLock(ctx.Sender)
+	userMu.Lock()
+	defer userMu.Unlock()
+
+	char, _, err := p.ensureCharacter(ctx.Sender)
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Failed to load your character.")
+	}
+	if !char.Alive {
+		return p.SendDM(ctx.Sender, "You're dead. The post office does not deliver from the ditch.")
+	}
+	if !char.CanDoHarvest(false) {
+		return p.SendDM(ctx.Sender, "You're out of harvest actions today.")
+	}
+
+	run, err := loadCoopRun(runID)
+	if err != nil || run == nil {
+		return p.SendDM(ctx.Sender, "Run not found.")
+	}
+	if run.Status != "active" {
+		return p.SendDM(ctx.Sender, "Run is not active. Gifts can only be sent during a running co-op.")
+	}
+
+	// Senders cannot be party members.
+	if existing, _ := loadCoopMember(runID, ctx.Sender); existing != nil {
+		return p.SendDM(ctx.Sender, "You're in the party. You can't send gifts to yourself.")
+	}
+
+	giftID, err := createCoopGift(runID, ctx.Sender, run.CurrentDay, giftType)
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't send the gift.")
+	}
+
+	// Charge the harvest action and persist.
+	char.HarvestActionsUsed++
+	if err := saveAdvCharacter(char); err != nil {
+		slog.Error("coop: save sender after gift", "err", err)
+	}
+
+	// Post the vote prompt to the game room.
+	gr := gamesRoom()
+	if gr != "" {
+		gift, _ := loadCoopGift(giftID)
+		members, _ := loadCoopMembers(runID)
+		postID, err := p.SendMessageID(gr, renderCoopGiftPost(run, gift, members))
+		if err == nil {
+			_ = saveCoopGiftPostID(giftID, postID)
+		}
+	}
+
+	return p.SendDM(ctx.Sender, fmt.Sprintf("📦 Gift dispatched (run #%d, day %d). One harvest action consumed. The party doesn't know what you sent.", runID, run.CurrentDay))
+}
+
+// ── Command: vote on a gift ─────────────────────────────────────────────────
+
+func (p *AdventurePlugin) handleCoopGiftVote(ctx MessageContext, args string) error {
+	parts := strings.Fields(args)
+	if len(parts) < 1 {
+		return p.SendDM(ctx.Sender, "Usage: `!coop giftvote <gift_id> <open|leave>` or `!coop giftvote <open|leave>` for the most recent unresolved gift.")
+	}
+
+	userMu := p.advUserLock(ctx.Sender)
+	userMu.Lock()
+	defer userMu.Unlock()
+
+	run, err := loadCoopRunForUser(ctx.Sender)
+	if err != nil || run == nil || run.Status != "active" {
+		return p.SendDM(ctx.Sender, "You're not in an active co-op run.")
+	}
+
+	var gift *CoopGift
+	var choice string
+	if len(parts) >= 2 {
+		giftID, perr := strconv.Atoi(parts[0])
+		if perr != nil {
+			return p.SendDM(ctx.Sender, "First arg must be the gift id, or just `open`/`leave` for the most recent.")
+		}
+		gift, _ = loadCoopGift(giftID)
+		choice = strings.ToLower(parts[1])
+	} else {
+		gift, _ = loadMostRecentUnresolvedGift(run.ID, run.CurrentDay)
+		choice = strings.ToLower(parts[0])
+	}
+	if gift == nil {
+		return p.SendDM(ctx.Sender, "No unresolved gift found.")
+	}
+	if gift.RunID != run.ID || gift.Day != run.CurrentDay {
+		return p.SendDM(ctx.Sender, "That gift isn't for your current run/day.")
+	}
+	if gift.VoteResult != "" {
+		return p.SendDM(ctx.Sender, "That gift has already resolved.")
+	}
+	if choice != "open" && choice != "leave" {
+		return p.SendDM(ctx.Sender, "Vote `open` or `leave`.")
+	}
+
+	if gift.Votes == nil {
+		gift.Votes = map[id.UserID]string{}
+	}
+	gift.Votes[ctx.Sender] = choice
+	if err := saveCoopGiftVotes(gift); err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't save your vote.")
+	}
+
+	gr := gamesRoom()
+	if gr != "" && gift.PostEventID != "" {
+		members, _ := loadCoopMembers(run.ID)
+		_ = p.EditMessage(gr, gift.PostEventID, renderCoopGiftPost(run, gift, members))
+	}
+	return p.SendDM(ctx.Sender, fmt.Sprintf("Gift #%d vote recorded: %s.", gift.ID, choice))
+}
+
+// ── Resolution ──────────────────────────────────────────────────────────────
+
+// coopResolveGifts is called inside coopResolveFloor to tally and apply each
+// unresolved gift for the current day. Returns the total modifier and a brief
+// summary line.
+func (p *AdventurePlugin) coopResolveGifts(run *CoopRun, leader id.UserID, day int) (int, string) {
+	gifts, err := loadDayCoopGifts(run.ID, day)
+	if err != nil || len(gifts) == 0 {
+		return 0, ""
+	}
+	totalMod := 0
+	var lines []string
+	for _, g := range gifts {
+		if g.VoteResult != "" {
+			continue
+		}
+		opens, leaves := 0, 0
+		var leaderVote string
+		for u, v := range g.Votes {
+			if v == "open" {
+				opens++
+			} else if v == "leave" {
+				leaves++
+			}
+			if u == leader {
+				leaderVote = v
+			}
+		}
+		var voteResult string
+		switch {
+		case opens > leaves:
+			voteResult = "opened"
+		case leaves > opens:
+			voteResult = "left"
+		case leaderVote == "open":
+			voteResult = "opened"
+		case leaderVote == "leave":
+			voteResult = "left"
+		default:
+			voteResult = "left" // default for full abstention
+		}
+
+		var mod int
+		var outcome string
+		switch g.GiftType {
+		case coopGiftBasket:
+			if voteResult == "opened" {
+				mod = coopGiftBasketOpened
+				outcome = "boost"
+			} else {
+				mod = coopGiftBasketUnopened
+				outcome = "reduction"
+			}
+		case coopGiftMimic:
+			if voteResult == "opened" {
+				mod = coopGiftMimicOpened
+				outcome = "reduction"
+			} else {
+				mod = coopGiftMimicUnopened
+				outcome = "boost"
+			}
+		}
+		totalMod += mod
+		_ = resolveCoopGift(g.ID, voteResult, outcome, mod)
+		lines = append(lines, fmt.Sprintf("  %s gift from %s — %s → %+d%%",
+			titleCaseWord(g.GiftType), coopDisplayName(p, g.SenderID), voteResult, mod))
+		_ = p.SendDM(g.SenderID, renderCoopGiftSenderDM(&g, voteResult, mod))
+	}
+	if len(lines) == 0 {
+		return 0, ""
+	}
+	return totalMod, "Gifts:\n" + strings.Join(lines, "\n")
+}
+
+// ── DB ──────────────────────────────────────────────────────────────────────
+
+func createCoopGift(runID int, sender id.UserID, day int, giftType string) (int, error) {
+	d := db.Get()
+	res, err := d.Exec(`INSERT INTO coop_dungeon_gifts (run_id, sender_id, day, gift_type)
+		VALUES (?, ?, ?, ?)`, runID, string(sender), day, giftType)
+	if err != nil {
+		return 0, err
+	}
+	id64, _ := res.LastInsertId()
+	return int(id64), nil
+}
+
+func loadCoopGift(giftID int) (*CoopGift, error) {
+	d := db.Get()
+	g := &CoopGift{}
+	var sender, votesJSON string
+	var voteResult, outcome, postID sql.NullString
+	err := d.QueryRow(`SELECT id, run_id, sender_id, day, gift_type,
+		votes, vote_result, outcome, modifier, post_event_id
+		FROM coop_dungeon_gifts WHERE id = ?`, giftID).Scan(
+		&g.ID, &g.RunID, &sender, &g.Day, &g.GiftType,
+		&votesJSON, &voteResult, &outcome, &g.Modifier, &postID)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	g.SenderID = id.UserID(sender)
+	g.Votes = parseCoopVotes(votesJSON)
+	if voteResult.Valid {
+		g.VoteResult = voteResult.String
+	}
+	if outcome.Valid {
+		g.Outcome = outcome.String
+	}
+	if postID.Valid {
+		g.PostEventID = id.EventID(postID.String)
+	}
+	return g, nil
+}
+
+func loadDayCoopGifts(runID, day int) ([]CoopGift, error) {
+	d := db.Get()
+	rows, err := d.Query(`SELECT id, run_id, sender_id, day, gift_type,
+		votes, vote_result, outcome, modifier, post_event_id
+		FROM coop_dungeon_gifts WHERE run_id = ? AND day = ? ORDER BY id`, runID, day)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []CoopGift
+	for rows.Next() {
+		g := CoopGift{}
+		var sender, votesJSON string
+		var voteResult, outcome, postID sql.NullString
+		if err := rows.Scan(&g.ID, &g.RunID, &sender, &g.Day, &g.GiftType,
+			&votesJSON, &voteResult, &outcome, &g.Modifier, &postID); err != nil {
+			return nil, err
+		}
+		g.SenderID = id.UserID(sender)
+		g.Votes = parseCoopVotes(votesJSON)
+		if voteResult.Valid {
+			g.VoteResult = voteResult.String
+		}
+		if outcome.Valid {
+			g.Outcome = outcome.String
+		}
+		if postID.Valid {
+			g.PostEventID = id.EventID(postID.String)
+		}
+		out = append(out, g)
+	}
+	return out, rows.Err()
+}
+
+func loadAllCoopGifts(runID int) ([]CoopGift, error) {
+	d := db.Get()
+	rows, err := d.Query(`SELECT id, run_id, sender_id, day, gift_type,
+		votes, vote_result, outcome, modifier, post_event_id
+		FROM coop_dungeon_gifts WHERE run_id = ? ORDER BY id`, runID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []CoopGift
+	for rows.Next() {
+		g := CoopGift{}
+		var sender, votesJSON string
+		var voteResult, outcome, postID sql.NullString
+		if err := rows.Scan(&g.ID, &g.RunID, &sender, &g.Day, &g.GiftType,
+			&votesJSON, &voteResult, &outcome, &g.Modifier, &postID); err != nil {
+			return nil, err
+		}
+		g.SenderID = id.UserID(sender)
+		g.Votes = parseCoopVotes(votesJSON)
+		if voteResult.Valid {
+			g.VoteResult = voteResult.String
+		}
+		if outcome.Valid {
+			g.Outcome = outcome.String
+		}
+		out = append(out, g)
+	}
+	return out, rows.Err()
+}
+
+func loadMostRecentUnresolvedGift(runID, day int) (*CoopGift, error) {
+	gifts, err := loadDayCoopGifts(runID, day)
+	if err != nil {
+		return nil, err
+	}
+	for i := len(gifts) - 1; i >= 0; i-- {
+		if gifts[i].VoteResult == "" {
+			g := gifts[i]
+			return &g, nil
+		}
+	}
+	return nil, nil
+}
+
+func saveCoopGiftVotes(g *CoopGift) error {
+	d := db.Get()
+	jsonBytes, err := json.Marshal(serializeCoopVotes(g.Votes))
+	if err != nil {
+		return err
+	}
+	_, err = d.Exec(`UPDATE coop_dungeon_gifts SET votes = ? WHERE id = ?`,
+		string(jsonBytes), g.ID)
+	return err
+}
+
+func saveCoopGiftPostID(giftID int, eventID id.EventID) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_gifts SET post_event_id = ? WHERE id = ?`,
+		string(eventID), giftID)
+	return err
+}
+
+func resolveCoopGift(giftID int, voteResult, outcome string, modifier int) error {
+	d := db.Get()
+	_, err := d.Exec(`UPDATE coop_dungeon_gifts
+		SET vote_result = ?, outcome = ?, modifier = ?, resolved_at = CURRENT_TIMESTAMP
+		WHERE id = ?`, voteResult, outcome, modifier, giftID)
+	return err
+}
+
+// ── Render ──────────────────────────────────────────────────────────────────
+
+func renderCoopGiftPost(run *CoopRun, gift *CoopGift, members []CoopMember) string {
+	var sb strings.Builder
+	flavor := ""
+	if len(TwinBeeGiftArrival) > 0 {
+		flavor = TwinBeeGiftArrival[rand.IntN(len(TwinBeeGiftArrival))]
+	}
+	sb.WriteString(fmt.Sprintf("📦 **Gift #%d arrived — Co-op #%d, Day %d**\n\n", gift.ID, run.ID, gift.Day))
+	if flavor != "" {
+		sb.WriteString(flavor)
+		sb.WriteString("\n\n")
+	}
+	sb.WriteString("Vote with `!coop giftvote " + strconv.Itoa(gift.ID) + " open|leave`. Resolved at next daily tick.\n\n")
+	opens, leaves := 0, 0
+	for _, v := range gift.Votes {
+		if v == "open" {
+			opens++
+		} else if v == "leave" {
+			leaves++
+		}
+	}
+	sb.WriteString(fmt.Sprintf("Current votes: open (%d) · leave (%d)", opens, leaves))
+	awaiting := 0
+	for _, m := range members {
+		if _, ok := gift.Votes[m.UserID]; !ok {
+			awaiting++
+		}
+	}
+	if awaiting > 0 && awaiting < len(members) {
+		sb.WriteString(fmt.Sprintf("\nAwaiting: %d of %d", awaiting, len(members)))
+	}
+	return sb.String()
+}
+
+func renderCoopGiftSenderDM(g *CoopGift, voteResult string, mod int) string {
+	pickFrom := func(pool []string) string {
+		if len(pool) == 0 {
+			return ""
+		}
+		return pool[rand.IntN(len(pool))]
+	}
+	switch {
+	case g.GiftType == coopGiftBasket && voteResult == "opened":
+		return fmt.Sprintf("📦 Your care basket was opened. %s (%+d%% to today's floor)", pickFrom(TwinBeeGiftBasketOpened), mod)
+	case g.GiftType == coopGiftBasket && voteResult == "left":
+		return fmt.Sprintf("📦 Your care basket was not opened. %s (%+d%%)", pickFrom(TwinBeeGiftBasketUnopened), mod)
+	case g.GiftType == coopGiftMimic && voteResult == "opened":
+		return fmt.Sprintf("📦 Your mimic was opened. %s (%+d%%)", pickFrom(TwinBeeGiftMimicOpened), mod)
+	case g.GiftType == coopGiftMimic && voteResult == "left":
+		return fmt.Sprintf("📦 Your mimic was not opened. %s (%+d%%)", pickFrom(TwinBeeGiftMimicUnopened), mod)
+	}
+	return "📦 Your gift resolved."
+}
+
+// renderCoopGiftLog returns the public end-of-run gift log.
+func renderCoopGiftLog(p *AdventurePlugin, runID int) string {
+	gifts, err := loadAllCoopGifts(runID)
+	if err != nil || len(gifts) == 0 {
+		return ""
+	}
+	var sb strings.Builder
+	sb.WriteString("📦 Gift Log:\n")
+	for _, g := range gifts {
+		result := g.VoteResult
+		if result == "" {
+			result = "unresolved"
+		}
+		sb.WriteString(fmt.Sprintf("  Day %d: %s → %s → %s → %+d%%\n",
+			g.Day, coopDisplayName(p, g.SenderID), titleCaseWord(g.GiftType), result, g.Modifier))
+	}
+	return sb.String()
+}
diff --git a/internal/plugin/coop_dungeon_render.go b/internal/plugin/coop_dungeon_render.go
new file mode 100644
index 0000000..9bcd42d
--- /dev/null
+++ b/internal/plugin/coop_dungeon_render.go
@@ -0,0 +1,220 @@
+package plugin
+
+import (
+	"fmt"
+	"math/rand/v2"
+	"strings"
+	"time"
+
+	"maunium.net/go/mautrix/id"
+)
+
+func coopDisplayName(p *AdventurePlugin, userID id.UserID) string {
+	char, err := loadAdvCharacter(userID)
+	if err == nil && char.DisplayName != "" {
+		return char.DisplayName
+	}
+	if p != nil {
+		return p.DisplayName(userID)
+	}
+	return string(userID)
+}
+
+func renderCoopInvite(run *CoopRun, members []CoopMember, leaderName string) string {
+	def := coopTierTable[run.Tier]
+	closes := run.CreatedAt.Add(coopInviteWindow).Format("Mon 15:04 UTC")
+	return fmt.Sprintf(
+		"⚔️ %s is opening a Co-op Dungeon — **Tier %d (%s)**, run #%d.\n"+
+			"Days: %d. Reward pool base: €%d (split among the party).\n"+
+			"Party: %d/%d. Type `!coop join %d` to enter.\n"+
+			"Locks at %s. Newbies are a liability — you knew that going in.",
+		leaderName, run.Tier, def.difficulty, run.ID,
+		def.totalDays, def.rewardBase,
+		len(members), coopMaxPartySize, run.ID, closes)
+}
+
+func renderCoopLock(run *CoopRun, members []CoopMember, p *AdventurePlugin) string {
+	var sb strings.Builder
+	def := coopTierTable[run.Tier]
+	sb.WriteString(fmt.Sprintf("⚔️ Tier %d Co-op #%d is locked.\n", run.Tier, run.ID))
+	sb.WriteString(fmt.Sprintf("Difficulty: %s. Days: %d. Reward pool: €%d.\n\nParty (turn order):\n",
+		def.difficulty, run.TotalDays, def.rewardBase))
+	for _, m := range members {
+		warn := ""
+		if m.IsLiability {
+			warn = " ⚠️ liability"
+		}
+		sb.WriteString(fmt.Sprintf("  %d. %s%s\n", m.TurnOrder+1, coopDisplayName(p, m.UserID), warn))
+	}
+	sb.WriteString("\nDay 1 begins now. Each member has until the next daily tick to fund. Inactive = None (-10%).")
+	bets, _ := loadCoopBets(run.ID)
+	sb.WriteString("\n\n")
+	sb.WriteString(renderCoopOddsLine(run, members, bets))
+	return sb.String()
+}
+
+func renderCoopFundingPrompt(run *CoopRun, day int) string {
+	var sb strings.Builder
+	sb.WriteString(fmt.Sprintf("⚔️ Co-op #%d — Day %d/%d. Pick your funding tier with `!coop fund <tier>`.\n\n",
+		run.ID, day, run.TotalDays))
+	for _, t := range coopFundingOrder {
+		def := coopFundingTable[t]
+		sb.WriteString(fmt.Sprintf("  • `%s` — €%d, %+d%%\n", t, def.cost, def.modifier))
+	}
+	sb.WriteString("\nNo decision before the next daily tick = auto-played as None (-10%). Funding is non-refundable.")
+	return sb.String()
+}
+
+func renderCoopDailyResult(p *AdventurePlugin, run *CoopRun, members []CoopMember, day int,
+	choices map[string]CoopFundingTier, successPct int, won bool, autoPlayed []*CoopMember,
+	event *CoopEvent, winning string, eventMod int) string {
+
+	var sb strings.Builder
+	def := coopTierTable[run.Tier]
+	header := "✅ Floor cleared"
+	if !won {
+		header = "💥 Wipe"
+	}
+	if won && day >= run.TotalDays {
+		header = "🏆 Final floor cleared"
+	}
+
+	sb.WriteString(fmt.Sprintf("⚔️ Co-op #%d — Tier %d (%s), Day %d/%d\n",
+		run.ID, run.Tier, def.difficulty, day, run.TotalDays))
+	sb.WriteString(fmt.Sprintf("Success chance: %d%%.  %s.\n", successPct, header))
+
+	if event != nil {
+		sb.WriteString(fmt.Sprintf("Floor event: %s. Party voted **%s** (%+d%%).\n",
+			titleCaseWord(string(event.Category)), winning, eventMod))
+	}
+	sb.WriteString("\nFunding:\n")
+
+	for _, m := range members {
+		t := choices[string(m.UserID)]
+		fdef := coopFundingTable[t]
+		auto := ""
+		for _, ap := range autoPlayed {
+			if ap.UserID == m.UserID {
+				auto = " ← auto-played"
+				break
+			}
+		}
+		sb.WriteString(fmt.Sprintf("  %s: %s (%+d%%)%s\n",
+			coopDisplayName(p, m.UserID), fdef.label, fdef.modifier, auto))
+	}
+
+	if event != nil {
+		sb.WriteString("\n_TwinBee:_ ")
+		sb.WriteString(coopTwinBeeReaction(event, winning, won))
+	}
+
+	if !won {
+		sb.WriteString("\n\nThe dungeon does not editorialize. Combat actions for today are refunded if any. Funding is gone.")
+	} else if day < run.TotalDays {
+		sb.WriteString(fmt.Sprintf("\n\nNext floor unlocks at the next daily tick. %d day(s) remain.", run.TotalDays-day))
+		bets, _ := loadCoopBets(run.ID)
+		sb.WriteString("\n")
+		sb.WriteString(renderCoopOddsLine(run, members, bets))
+	}
+	return sb.String()
+}
+
+// coopTwinBeeReaction picks an outcome line based on whether his recommendation
+// matched the winning vote and whether the floor succeeded.
+func coopTwinBeeReaction(event *CoopEvent, winning string, won bool) string {
+	pickFrom := func(pool []string) string {
+		if len(pool) == 0 {
+			return ""
+		}
+		return pool[rand.IntN(len(pool))]
+	}
+	switch {
+	case event.Recommended == winning && won:
+		return pickFrom(TwinBeeOutcomeCorrect)
+	case event.Recommended == winning && !won:
+		return pickFrom(TwinBeeOutcomeWrong)
+	case event.Recommended != winning && won:
+		return pickFrom(TwinBeeOutcomeNotRecommendedGood)
+	default:
+		return pickFrom(TwinBeeOutcomeNotRecommendedBad)
+	}
+}
+
+// renderCoopEventPost is the game-room post for a floor event vote prompt.
+// Edited in place as votes come in.
+func renderCoopEventPost(run *CoopRun, members []CoopMember, event *CoopEvent) string {
+	var sb strings.Builder
+	flavorPool := coopEventCategoryFlavor(event.Category)
+	flavor := ""
+	if event.EventIndex < len(flavorPool) {
+		flavor = flavorPool[event.EventIndex]
+	}
+	sb.WriteString(fmt.Sprintf("🗺️ **Co-op #%d — Day %d/%d, %s event**\n\n",
+		run.ID, event.Day, run.TotalDays, titleCaseWord(string(event.Category))))
+	sb.WriteString(flavor)
+	sb.WriteString("\n\nVote with `!coop vote A` (or B/C). 24h or until next tick. Ties go to the leader.\n\n")
+
+	tally := map[string]int{}
+	for _, v := range event.Votes {
+		tally[v]++
+	}
+	parts := []string{}
+	for _, label := range coopEventOptionLabels(event.Category, event.EventIndex) {
+		parts = append(parts, fmt.Sprintf("%s (%d)", label, tally[label]))
+	}
+	sb.WriteString("Current votes: ")
+	sb.WriteString(strings.Join(parts, " · "))
+
+	abstained := []string{}
+	for _, m := range members {
+		if _, voted := event.Votes[m.UserID]; !voted {
+			abstained = append(abstained, string(m.UserID))
+		}
+	}
+	if len(abstained) > 0 && len(abstained) < len(members) {
+		sb.WriteString(fmt.Sprintf("\nAwaiting: %d of %d", len(abstained), len(members)))
+	}
+	return sb.String()
+}
+
+func titleCaseWord(s string) string {
+	if s == "" {
+		return s
+	}
+	return strings.ToUpper(s[:1]) + s[1:]
+}
+
+func renderCoopStatus(p *AdventurePlugin, run *CoopRun, members []CoopMember) string {
+	var sb strings.Builder
+	def := coopTierTable[run.Tier]
+	sb.WriteString(fmt.Sprintf("⚔️ Co-op #%d — Tier %d (%s)\n", run.ID, run.Tier, def.difficulty))
+	sb.WriteString(fmt.Sprintf("Status: %s.  Day %d/%d.  Pool: €%d.\n\nParty:\n",
+		run.Status, run.CurrentDay, run.TotalDays, run.GoldPool))
+
+	for _, m := range members {
+		warn := ""
+		if m.IsLiability {
+			warn = " ⚠️"
+		}
+		todayLabel := "—"
+		if run.CurrentDay >= 1 {
+			if t, ok := m.DailyFunding[run.CurrentDay]; ok {
+				todayLabel = coopFundingTable[t].label
+			} else {
+				todayLabel = "(unset)"
+			}
+		}
+		sb.WriteString(fmt.Sprintf("  %d. %s%s — today: %s, contributed: €%d\n",
+			m.TurnOrder+1, coopDisplayName(p, m.UserID), warn, todayLabel, m.TotalContributed))
+	}
+	if run.Status == "open" {
+		closes := run.CreatedAt.Add(coopInviteWindow)
+		sb.WriteString(fmt.Sprintf("\nLocks in: %s.", time.Until(closes).Truncate(time.Minute)))
+	}
+	if run.Status == "open" || run.Status == "active" {
+		bets, _ := loadCoopBets(run.ID)
+		sb.WriteString("\n")
+		sb.WriteString(renderCoopOddsLine(run, members, bets))
+	}
+	return sb.String()
+}
diff --git a/internal/plugin/coop_dungeon_scheduler.go b/internal/plugin/coop_dungeon_scheduler.go
new file mode 100644
index 0000000..d82ffe9
--- /dev/null
+++ b/internal/plugin/coop_dungeon_scheduler.go
@@ -0,0 +1,483 @@
+package plugin
+
+import (
+	"fmt"
+	"log/slog"
+	"math/rand/v2"
+	"strings"
+	"time"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// coopTicker fires once per UTC day to:
+//  1. Lock open invites whose 24h window has elapsed.
+//  2. For each active run, resolve the day's floor and advance/complete.
+//
+// Reuses the daily_prefetch job-completion guard so a bot restart on the same
+// UTC day does not double-process.
+func (p *AdventurePlugin) coopTicker() {
+	ticker := time.NewTicker(1 * time.Minute)
+	defer ticker.Stop()
+
+	for range ticker.C {
+		now := time.Now().UTC()
+		// Run at the same minute as the morning DM (08:00 UTC) — same cadence as
+		// the rest of the adventure system.
+		if now.Hour() != p.morningHour || now.Minute() != 0 {
+			continue
+		}
+		dateKey := now.Format("2006-01-02")
+		jobName := "coop_dungeon_daily"
+		if db.JobCompleted(jobName, dateKey) {
+			continue
+		}
+		slog.Info("coop: daily tick")
+		p.coopProcessLocks()
+		p.coopProcessActiveRuns()
+		db.MarkJobCompleted(jobName, dateKey)
+	}
+}
+
+// ── Lock Phase ──────────────────────────────────────────────────────────────
+
+// coopProcessLocks closes invites whose 24h window has elapsed: locks parties
+// of 2+, cancels solo runs.
+func (p *AdventurePlugin) coopProcessLocks() {
+	runs, err := loadOpenCoopRuns()
+	if err != nil {
+		slog.Error("coop: load open runs", "err", err)
+		return
+	}
+	now := time.Now().UTC()
+	for _, run := range runs {
+		if now.Before(run.CreatedAt.Add(coopInviteWindow)) {
+			continue
+		}
+		members, err := loadCoopMembers(run.ID)
+		if err != nil {
+			slog.Error("coop: load members for lock", "run", run.ID, "err", err)
+			continue
+		}
+		if len(members) < coopMinPartySize {
+			// Cancel solo runs and refund nothing (no funding has been spent yet).
+			_ = setCoopRunStatus(run.ID, "cancelled")
+			gr := gamesRoom()
+			if gr != "" {
+				_ = p.SendMessage(gr, fmt.Sprintf("⚔️ Tier %d Co-op #%d expired with no party. Cancelled.", run.Tier, run.ID))
+			}
+			_ = p.SendDM(run.LeaderID, fmt.Sprintf("Co-op #%d expired before anyone joined. Combat action refunded.", run.ID))
+			continue
+		}
+
+		// Lock: deduct combat action from each member, mark active, post lock notice.
+		if err := lockCoopRun(run.ID); err != nil {
+			slog.Error("coop: lock run", "run", run.ID, "err", err)
+			continue
+		}
+		for _, m := range members {
+			char, err := loadAdvCharacter(m.UserID)
+			if err != nil {
+				continue
+			}
+			if char.CanDoCombat(false) {
+				char.CombatActionsUsed++
+				char.ActionTakenToday = true
+				char.LastActionDate = now.Format("2006-01-02")
+				_ = saveAdvCharacter(char)
+			}
+		}
+		fresh, _ := loadCoopRun(run.ID)
+		gr := gamesRoom()
+		if gr != "" {
+			_ = p.SendMessage(gr, renderCoopLock(fresh, members, p))
+		}
+		// Per-player DM with funding instructions.
+		for _, m := range members {
+			_ = p.SendDM(m.UserID, renderCoopFundingPrompt(fresh, 1))
+		}
+		// Generate and post day-1 floor event.
+		p.coopGenerateAndPostEvent(fresh, members, 1)
+	}
+}
+
+// coopGenerateAndPostEvent picks a category-weighted event for the given day,
+// stores it, and posts the vote prompt to the game room with TwinBee narration.
+func (p *AdventurePlugin) coopGenerateAndPostEvent(run *CoopRun, members []CoopMember, day int) {
+	cat := pickCoopEventCategory(run.Tier)
+	idx := pickCoopEvent(cat)
+	rec := coopEventRecommended(cat, idx)
+	if err := createCoopEvent(run.ID, day, cat, idx, rec); err != nil {
+		slog.Error("coop: create event", "run", run.ID, "day", day, "err", err)
+		return
+	}
+	gr := gamesRoom()
+	if gr == "" {
+		return
+	}
+	event, _ := loadCoopEvent(run.ID, day)
+	if event == nil {
+		return
+	}
+	postID, err := p.SendMessageID(gr, renderCoopEventPost(run, members, event))
+	if err != nil {
+		slog.Error("coop: post event", "err", err)
+		return
+	}
+	_ = saveCoopEventPostID(run.ID, day, postID)
+}
+
+// ── Daily Resolution ────────────────────────────────────────────────────────
+
+func (p *AdventurePlugin) coopProcessActiveRuns() {
+	runs, err := loadActiveCoopRuns()
+	if err != nil {
+		slog.Error("coop: load active runs", "err", err)
+		return
+	}
+	today := time.Now().UTC().Format("2006-01-02")
+	for _, run := range runs {
+		// Skip runs locked on this same tick — they need a full day for
+		// funding decisions and voting before the first floor resolves.
+		if run.LockedAt != nil && run.LockedAt.UTC().Format("2006-01-02") == today {
+			continue
+		}
+		if err := p.coopResolveFloor(run); err != nil {
+			slog.Error("coop: resolve floor", "run", run.ID, "err", err)
+		}
+	}
+}
+
+// coopResolveFloor processes the current day's floor: auto-plays missing
+// funders, rolls outcome, advances or completes the run.
+func (p *AdventurePlugin) coopResolveFloor(run *CoopRun) error {
+	day := run.CurrentDay
+	members, err := loadCoopMembers(run.ID)
+	if err != nil {
+		return err
+	}
+
+	// Auto-play any member who didn't fund.
+	autoPlayed := []*CoopMember{}
+	for i := range members {
+		m := &members[i]
+		if _, ok := m.DailyFunding[day]; !ok {
+			m.DailyFunding[day] = CoopFundNone
+			if err := saveCoopMemberFunding(m); err != nil {
+				slog.Error("coop: auto-play save", "run", run.ID, "user", m.UserID, "err", err)
+			}
+			autoPlayed = append(autoPlayed, m)
+		}
+	}
+
+	// Compute success modifier: base = (100 - baseDifficulty), adjusted by
+	// funding, party levels, pets, and the floor event vote.
+	totalMod := 0
+	choices := make(map[string]CoopFundingTier, len(members))
+	tierDef := coopTierTable[run.Tier]
+	for _, m := range members {
+		tier, mod := coopMemberModifier(&m, day)
+		choices[string(m.UserID)] = tier
+		totalMod += mod
+		// Level + pet bonuses pulled fresh per-floor; they reflect current
+		// state (a player may have leveled up mid-run).
+		char, err := loadAdvCharacter(m.UserID)
+		if err != nil {
+			continue
+		}
+		totalMod += coopLevelBonus(char.CombatLevel, tierDef.minLevel)
+		totalMod += coopPetBonus(char)
+	}
+
+	// Tally vote on today's floor event. Ties go to the leader's vote (or
+	// option A if leader didn't vote either).
+	event, _ := loadCoopEvent(run.ID, day)
+	winning := ""
+	eventMod := 0
+	if event != nil {
+		winning = coopTallyVote(event, run.LeaderID)
+		eventMod = coopEventOptionModifier(event.Category, event.EventIndex, winning)
+		totalMod += eventMod
+	}
+
+	// Resolve gifts received on this day.
+	giftMod, giftSummary := p.coopResolveGifts(run, run.LeaderID, day)
+	totalMod += giftMod
+
+	successPct := 100 - run.BaseDifficulty + totalMod
+	if successPct < 5 {
+		successPct = 5
+	}
+	if successPct > 95 {
+		successPct = 95
+	}
+
+	roll := rand.IntN(100)
+	floorWon := roll < successPct
+
+	// Persist the event resolution before posting (so a crash mid-post still
+	// records what happened for TwinBee helpfulness tracking).
+	if event != nil {
+		outcomeStr := "failure"
+		if floorWon {
+			outcomeStr = "success"
+		}
+		_ = resolveCoopEvent(run.ID, day, winning, outcomeStr, eventMod)
+	}
+
+	gr := gamesRoom()
+	dailyPost := renderCoopDailyResult(p, run, members, day, choices, successPct, floorWon, autoPlayed, event, winning, eventMod)
+	if giftSummary != "" {
+		dailyPost += "\n\n" + giftSummary
+	}
+	if gr != "" {
+		_ = p.SendMessage(gr, dailyPost)
+	}
+
+	if !floorWon {
+		// Wipe. Combat actions are only consumed at lock (day 1), so only a
+		// day-1 wipe has anything to refund.
+		if day == 1 {
+			now := time.Now().UTC().Format("2006-01-02")
+			for _, m := range members {
+				char, err := loadAdvCharacter(m.UserID)
+				if err != nil {
+					continue
+				}
+				if char.LastActionDate == now && char.CombatActionsUsed > 0 {
+					char.CombatActionsUsed--
+					_ = saveAdvCharacter(char)
+				}
+			}
+		}
+		_ = completeCoopRun(run.ID, "wiped", 0)
+		// Resolve betting pool — failure side wins on a wipe.
+		freshRun, _ := loadCoopRun(run.ID)
+		if freshRun != nil {
+			summary := p.coopResolveBets(freshRun, false)
+			giftLog := renderCoopGiftLog(p, run.ID)
+			parts := []string{}
+			if summary != "" {
+				parts = append(parts, summary)
+			}
+			if giftLog != "" {
+				parts = append(parts, giftLog)
+			}
+			if len(parts) > 0 {
+				if gr := gamesRoom(); gr != "" {
+					_ = p.SendMessage(gr, strings.Join(parts, "\n\n"))
+				}
+			}
+		}
+		return nil
+	}
+
+	// Floor cleared — advance or complete.
+	if day >= run.TotalDays {
+		// Run complete — split reward.
+		def := coopTierTable[run.Tier]
+		reward := def.rewardBase
+		_ = completeCoopRun(run.ID, "complete", reward)
+		freshRun, _ := loadCoopRun(run.ID)
+		if freshRun != nil {
+			p.coopDistributeReward(freshRun, reward, members)
+		}
+		return nil
+	}
+	if err := advanceCoopDay(run.ID, day+1); err != nil {
+		return err
+	}
+	for _, m := range members {
+		_ = p.SendDM(m.UserID, renderCoopFundingPrompt(run, day+1))
+	}
+	// Generate next day's floor event.
+	freshRun, _ := loadCoopRun(run.ID)
+	if freshRun != nil {
+		p.coopGenerateAndPostEvent(freshRun, members, day+1)
+	}
+	return nil
+}
+
+// coopTallyVote counts votes; majority wins. Ties resolve to the leader's
+// vote if any, otherwise option A.
+func coopTallyVote(event *CoopEvent, leader id.UserID) string {
+	tally := map[string]int{}
+	for _, v := range event.Votes {
+		tally[v]++
+	}
+	bestCount := -1
+	var winners []string
+	for label, n := range tally {
+		if n > bestCount {
+			bestCount = n
+			winners = []string{label}
+		} else if n == bestCount {
+			winners = append(winners, label)
+		}
+	}
+	if len(winners) == 1 {
+		return winners[0]
+	}
+	if leaderVote, ok := event.Votes[leader]; ok {
+		for _, w := range winners {
+			if w == leaderVote {
+				return w
+			}
+		}
+	}
+	if len(winners) > 0 {
+		return winners[0]
+	}
+	return "A"
+}
+
+func (p *AdventurePlugin) coopDistributeReward(run *CoopRun, totalReward int, members []CoopMember) {
+	if len(members) == 0 || totalReward <= 0 {
+		return
+	}
+	share := totalReward / len(members)
+	gr := gamesRoom()
+	var lines []string
+	for _, m := range members {
+		net, _ := communityTax(m.UserID, float64(share), coopAdventureRake)
+		p.euro.Credit(m.UserID, net, "coop_dungeon_reward")
+		lines = append(lines, fmt.Sprintf("  %s: €%.0f (after tax)", coopDisplayName(p, m.UserID), net))
+		_ = p.SendDM(m.UserID, fmt.Sprintf("⚔️ Co-op #%d cleared. Your share: €%.0f.", run.ID, net))
+	}
+
+	// Generate item drops and distribute via weighted roll.
+	itemSummary := p.coopDistributeItems(run, members)
+
+	bettingSummary := p.coopResolveBets(run, true)
+	giftLog := renderCoopGiftLog(p, run.ID)
+	if gr != "" {
+		msg := fmt.Sprintf("⚔️ Co-op #%d cleared. Reward pool: €%d.\n\n%s",
+			run.ID, totalReward, strings.Join(lines, "\n"))
+		if itemSummary != "" {
+			msg += "\n\n" + itemSummary
+		}
+		if bettingSummary != "" {
+			msg += "\n\n" + bettingSummary
+		}
+		if giftLog != "" {
+			msg += "\n\n" + giftLog
+		}
+		_ = p.SendMessage(gr, msg)
+	}
+}
+
+// coopDistributeItems generates item drops for a successful run and assigns
+// each via weighted roll across party members (weight = total_contributed).
+// Items are added to the winner's inventory; returns a summary line.
+func (p *AdventurePlugin) coopDistributeItems(run *CoopRun, members []CoopMember) string {
+	loc := findAdvLocationByTier(AdvActivityDungeon, run.Tier)
+	if loc == nil {
+		return ""
+	}
+	// Item count scales with tier: T1 = 2, T5 = 6.
+	count := 2 + (run.Tier - 1)
+	var allItems []AdvItem
+	for i := 0; i < count; i++ {
+		allItems = append(allItems, generateAdvLoot(loc, false, 0)...)
+	}
+	if len(allItems) == 0 {
+		return ""
+	}
+	totalWeight := 0
+	for _, m := range members {
+		totalWeight += m.TotalContributed
+	}
+
+	var lines []string
+	for _, item := range allItems {
+		winner := coopWeightedItemWinner(members, totalWeight)
+		_ = addAdvInventoryItem(winner, item)
+		lines = append(lines, fmt.Sprintf("  %s (€%d) → %s", item.Name, item.Value, coopDisplayName(p, winner)))
+	}
+	if mwLine := p.coopMaybeMasterwork(run, members, totalWeight); mwLine != "" {
+		lines = append(lines, mwLine)
+	}
+	return "Item drops:\n" + strings.Join(lines, "\n")
+}
+
+// coopMaybeMasterwork grants a tier-appropriate masterwork drop on T4 (25%)
+// or T5 (guaranteed). Picks a random masterwork def at the run's tier from
+// the existing pool (mining sword / fishing armor / foraging boots), awards
+// it via the same weighted roll, and announces in the game room.
+//
+// Returns a one-line summary to splice into the completion post, or "".
+func (p *AdventurePlugin) coopMaybeMasterwork(run *CoopRun, members []CoopMember, totalWeight int) string {
+	if run.Tier < 4 {
+		return ""
+	}
+	if run.Tier == 4 && rand.Float64() >= 0.25 {
+		return ""
+	}
+
+	// Collect all masterwork defs at the run's tier.
+	candidates := []MasterworkDef{}
+	for _, def := range masterworkDefs {
+		if def.Tier == run.Tier {
+			candidates = append(candidates, def)
+		}
+	}
+	if len(candidates) == 0 {
+		return ""
+	}
+	def := candidates[rand.IntN(len(candidates))]
+	winner := coopWeightedItemWinner(members, totalWeight)
+	if winner == "" {
+		return ""
+	}
+
+	// Add to inventory as MasterworkGear (don't auto-equip — let the winner
+	// choose via !adventure equip; their existing gear may be better).
+	item := AdvItem{
+		Name:        def.Name,
+		Type:        "MasterworkGear",
+		Tier:        def.Tier,
+		Value:       0,
+		Slot:        def.Slot,
+		SkillSource: def.SkillSource,
+	}
+	if err := addAdvInventoryItem(winner, item); err != nil {
+		slog.Error("coop: masterwork inventory add", "winner", winner, "err", err)
+		return ""
+	}
+
+	char, _ := loadAdvCharacter(winner)
+	if char != nil {
+		char.MasterworkDropsReceived++
+		_ = saveAdvCharacter(char)
+	}
+
+	dmText := fmt.Sprintf("⭐ **Co-op Masterwork Drop: %s** (T%d %s)\n\n_%s_\n\nMasterwork %s — 1.25x effectiveness, +5%% %s success.\n\nAdded to inventory. `!adventure equip` to use it.",
+		def.Name, def.Tier, slotTitle(def.Slot), def.Description, slotTitle(def.Slot), def.SkillSource)
+	_ = p.SendDM(winner, dmText)
+
+	return fmt.Sprintf("⭐ Masterwork: %s (T%d %s) → %s",
+		def.Name, def.Tier, slotTitle(def.Slot), coopDisplayName(p, winner))
+}
+
+// coopWeightedItemWinner picks a member with probability proportional to their
+// total funding contribution. If no one has contributed (e.g., all None on
+// every day), falls back to uniform random.
+func coopWeightedItemWinner(members []CoopMember, totalWeight int) id.UserID {
+	if len(members) == 0 {
+		return ""
+	}
+	if totalWeight <= 0 {
+		return members[rand.IntN(len(members))].UserID
+	}
+	r := rand.IntN(totalWeight)
+	cum := 0
+	for _, m := range members {
+		cum += m.TotalContributed
+		if r < cum {
+			return m.UserID
+		}
+	}
+	return members[len(members)-1].UserID
+}
diff --git a/internal/plugin/coop_dungeon_test.go b/internal/plugin/coop_dungeon_test.go
new file mode 100644
index 0000000..19a6669
--- /dev/null
+++ b/internal/plugin/coop_dungeon_test.go
@@ -0,0 +1,332 @@
+package plugin
+
+import (
+	"testing"
+
+	"maunium.net/go/mautrix/id"
+)
+
+func TestParseCoopFundingTier(t *testing.T) {
+	cases := map[string]CoopFundingTier{
+		"none":       CoopFundNone,
+		"skip":       CoopFundNone,
+		"min":        CoopFundMinimal,
+		"minimal":    CoopFundMinimal,
+		"standard":   CoopFundStandard,
+		"std":        CoopFundStandard,
+		"aggressive": CoopFundAggressive,
+		"agg":        CoopFundAggressive,
+		"all_in":     CoopFundAllIn,
+		"all-in":     CoopFundAllIn,
+		"all in":     CoopFundAllIn,
+		"allin":      CoopFundAllIn,
+		"all":        CoopFundAllIn,
+		"":           "",
+		"garbage":    "",
+	}
+	for input, want := range cases {
+		got := parseCoopFundingTier(input)
+		if got != want {
+			t.Errorf("parseCoopFundingTier(%q) = %q, want %q", input, got, want)
+		}
+	}
+}
+
+func TestCoopMemberModifierLiabilityCap(t *testing.T) {
+	t.Parallel()
+
+	veteran := &CoopMember{
+		IsLiability:  false,
+		DailyFunding: map[int]CoopFundingTier{1: CoopFundAllIn},
+	}
+	noob := &CoopMember{
+		IsLiability:  true,
+		DailyFunding: map[int]CoopFundingTier{1: CoopFundAllIn},
+	}
+
+	if _, mod := coopMemberModifier(veteran, 1); mod != 30 {
+		t.Errorf("veteran All In modifier = %d, want 30", mod)
+	}
+	if _, mod := coopMemberModifier(noob, 1); mod != coopLiabilityCap {
+		t.Errorf("liability All In modifier = %d, want %d (cap)", mod, coopLiabilityCap)
+	}
+
+	missing := &CoopMember{DailyFunding: map[int]CoopFundingTier{}}
+	tier, mod := coopMemberModifier(missing, 1)
+	if tier != CoopFundNone || mod != -10 {
+		t.Errorf("missing-day default = (%q, %d), want (none, -10)", tier, mod)
+	}
+}
+
+func TestCoopFundingMapRoundtrip(t *testing.T) {
+	t.Parallel()
+
+	in := map[int]CoopFundingTier{
+		1: CoopFundMinimal,
+		3: CoopFundAllIn,
+		7: CoopFundNone,
+	}
+	encoded := serializeCoopFundingMap(in)
+	// JSON encode/decode via parse helper
+	bytes, _ := jsonMarshalCoop(encoded)
+	out := parseCoopFundingMap(string(bytes))
+
+	if len(out) != len(in) {
+		t.Fatalf("roundtrip lost entries: in %d out %d", len(in), len(out))
+	}
+	for k, v := range in {
+		if out[k] != v {
+			t.Errorf("day %d: got %q want %q", k, out[k], v)
+		}
+	}
+}
+
+func TestCoopTallyVote(t *testing.T) {
+	t.Parallel()
+
+	leader := id.UserID("@leader:test")
+	other := id.UserID("@other:test")
+	third := id.UserID("@third:test")
+
+	tests := []struct {
+		name   string
+		votes  map[id.UserID]string
+		want   string
+	}{
+		{"clear majority", map[id.UserID]string{leader: "A", other: "A", third: "B"}, "A"},
+		{"tie broken by leader", map[id.UserID]string{leader: "B", other: "A"}, "B"},
+		{"all abstained falls back to A", map[id.UserID]string{}, "A"},
+		{"tie no leader vote falls back deterministically", map[id.UserID]string{other: "A", third: "B"}, ""}, // "A" or "B" — accept either
+	}
+	for _, tc := range tests {
+		event := &CoopEvent{Votes: tc.votes}
+		got := coopTallyVote(event, leader)
+		if tc.want == "" {
+			if got != "A" && got != "B" {
+				t.Errorf("%s: got %q, want one of A/B", tc.name, got)
+			}
+			continue
+		}
+		if got != tc.want {
+			t.Errorf("%s: got %q, want %q", tc.name, got, tc.want)
+		}
+	}
+}
+
+func TestCoopEventOptionModifierKnownEvent(t *testing.T) {
+	t.Parallel()
+	// Obstacle 0 has options A=-8, B=0, C=12. Verify the lookup works.
+	if got := coopEventOptionModifier(CoopCatObstacle, 0, "A"); got != -8 {
+		t.Errorf("obstacle[0] A modifier = %d, want -8", got)
+	}
+	if got := coopEventOptionModifier(CoopCatObstacle, 0, "C"); got != 12 {
+		t.Errorf("obstacle[0] C modifier = %d, want 12", got)
+	}
+	if got := coopEventOptionModifier(CoopCatObstacle, 0, "Z"); got != 0 {
+		t.Errorf("unknown option = %d, want 0", got)
+	}
+}
+
+func TestCoopEventMetaConsistency(t *testing.T) {
+	t.Parallel()
+	cats := map[CoopEventCategory][]coopEventMeta{
+		CoopCatObstacle:    coopObstacleMeta,
+		CoopCatOpportunity: coopOpportunityMeta,
+		CoopCatCrisis:      coopCrisisMeta,
+		CoopCatEncounter:   coopEncounterMeta,
+	}
+	flavors := map[CoopEventCategory][]string{
+		CoopCatObstacle:    TwinBeeObstacle,
+		CoopCatOpportunity: TwinBeeOpportunity,
+		CoopCatCrisis:      TwinBeeCrisis,
+		CoopCatEncounter:   TwinBeeEncounter,
+	}
+	for cat, meta := range cats {
+		flavor := flavors[cat]
+		if len(meta) != len(flavor) {
+			t.Errorf("%s: meta has %d entries, flavor has %d", cat, len(meta), len(flavor))
+		}
+		for i, m := range meta {
+			if len(m.options) < 2 {
+				t.Errorf("%s[%d] has only %d options", cat, i, len(m.options))
+			}
+			recOK := false
+			for _, opt := range m.options {
+				if opt.label == m.recommended {
+					recOK = true
+				}
+			}
+			if !recOK {
+				t.Errorf("%s[%d] recommends %q which isn't an option", cat, i, m.recommended)
+			}
+		}
+	}
+}
+
+func TestCoopParimutuelPayouts(t *testing.T) {
+	t.Parallel()
+	a := id.UserID("@a:t")
+	b := id.UserID("@b:t")
+	c := id.UserID("@c:t")
+	d := id.UserID("@d:t")
+
+	bets := []CoopBet{
+		{PlayerID: a, Position: "success", Amount: 1000},
+		{PlayerID: b, Position: "success", Amount: 3000},
+		{PlayerID: c, Position: "failure", Amount: 5000},
+		{PlayerID: d, Position: "failure", Amount: 1000},
+	}
+	winners, total, rake, payouts := coopParimutuelPayouts(bets, "success")
+	if total != 10000 {
+		t.Errorf("total = %d, want 10000", total)
+	}
+	if rake != 1000 {
+		t.Errorf("rake = %d, want 1000 (10%%)", rake)
+	}
+	if len(winners) != 2 {
+		t.Errorf("winners = %d, want 2", len(winners))
+	}
+	// Net pool = 9000. a put in 1000/4000 = 25% of winning side → 2250.
+	// b put in 3000/4000 = 75% → 6750.
+	if payouts[a] != 2250 {
+		t.Errorf("a payout = %d, want 2250", payouts[a])
+	}
+	if payouts[b] != 6750 {
+		t.Errorf("b payout = %d, want 6750", payouts[b])
+	}
+	if payouts[c] != 0 {
+		t.Errorf("c payout = %d, want 0 (loser)", payouts[c])
+	}
+}
+
+func TestCoopWeightedItemWinnerDistribution(t *testing.T) {
+	t.Parallel()
+	a := id.UserID("@a:t")
+	b := id.UserID("@b:t")
+	c := id.UserID("@c:t")
+	members := []CoopMember{
+		{UserID: a, TotalContributed: 7000}, // 70%
+		{UserID: b, TotalContributed: 2000}, // 20%
+		{UserID: c, TotalContributed: 1000}, // 10%
+	}
+	totalWeight := 10000
+	wins := map[id.UserID]int{}
+	const trials = 100_000
+	for i := 0; i < trials; i++ {
+		w := coopWeightedItemWinner(members, totalWeight)
+		wins[w]++
+	}
+	// Allow ±2% absolute deviation per side at this trial count.
+	check := func(uid id.UserID, expected float64) {
+		actual := float64(wins[uid]) / float64(trials)
+		if actual < expected-0.02 || actual > expected+0.02 {
+			t.Errorf("%s: got %.3f, want ~%.2f", uid, actual, expected)
+		}
+	}
+	check(a, 0.70)
+	check(b, 0.20)
+	check(c, 0.10)
+}
+
+func TestCoopWeightedItemWinnerNoContributions(t *testing.T) {
+	t.Parallel()
+	a := id.UserID("@a:t")
+	b := id.UserID("@b:t")
+	members := []CoopMember{
+		{UserID: a, TotalContributed: 0},
+		{UserID: b, TotalContributed: 0},
+	}
+	wins := map[id.UserID]int{}
+	for i := 0; i < 10_000; i++ {
+		wins[coopWeightedItemWinner(members, 0)]++
+	}
+	if wins[a] == 0 || wins[b] == 0 {
+		t.Errorf("uniform fallback didn't pick both: %v", wins)
+	}
+}
+
+func TestCoopMasterworkTierGate(t *testing.T) {
+	t.Parallel()
+	// Verify that masterwork defs exist at T4 and T5 (so coopMaybeMasterwork
+	// has candidates) and that nothing exists at T1-T3 in the dungeon path.
+	tiers := map[int]int{}
+	for _, def := range masterworkDefs {
+		tiers[def.Tier]++
+	}
+	if tiers[4] == 0 {
+		t.Errorf("no T4 masterwork defs found — coop T4 drops will silently no-op")
+	}
+	if tiers[5] == 0 {
+		t.Errorf("no T5 masterwork defs found — coop T5 drops will silently no-op")
+	}
+}
+
+func TestCoopGiftEVSymmetric(t *testing.T) {
+	t.Parallel()
+	// At a 50/50 sender mix, "always open" and "always leave" should both
+	// have EV = 0. Anything else means players have a dominant strategy.
+	openEV := 0.5*float64(coopGiftBasketOpened) + 0.5*float64(coopGiftMimicOpened)
+	leaveEV := 0.5*float64(coopGiftBasketUnopened) + 0.5*float64(coopGiftMimicUnopened)
+	if openEV != 0 {
+		t.Errorf("always-open EV = %.2f, want 0", openEV)
+	}
+	if leaveEV != 0 {
+		t.Errorf("always-leave EV = %.2f, want 0", leaveEV)
+	}
+}
+
+func TestCoopParimutuelNoWinners(t *testing.T) {
+	t.Parallel()
+	bets := []CoopBet{
+		{PlayerID: "@x:t", Position: "failure", Amount: 5000},
+	}
+	winners, total, rake, payouts := coopParimutuelPayouts(bets, "success")
+	if len(winners) != 0 {
+		t.Errorf("winners = %d, want 0", len(winners))
+	}
+	if total != 5000 || rake != 500 {
+		t.Errorf("total=%d rake=%d, want 5000 500", total, rake)
+	}
+	if len(payouts) != 0 {
+		t.Errorf("payouts has %d entries; want 0", len(payouts))
+	}
+}
+
+func TestCoopTierTableComplete(t *testing.T) {
+	for tier := 1; tier <= 5; tier++ {
+		def, ok := coopTierTable[tier]
+		if !ok {
+			t.Errorf("missing tier %d", tier)
+			continue
+		}
+		if def.totalDays < 2 || def.totalDays > 7 {
+			t.Errorf("tier %d totalDays %d out of range", tier, def.totalDays)
+		}
+		if def.baseFailurePct < 1 || def.baseFailurePct > 99 {
+			t.Errorf("tier %d baseFailurePct %d out of range", tier, def.baseFailurePct)
+		}
+		if def.rewardBase <= 0 {
+			t.Errorf("tier %d rewardBase %d not positive", tier, def.rewardBase)
+		}
+	}
+}
+
+// jsonMarshalCoop is a tiny indirection so the test file doesn't import
+// encoding/json directly (we only need it for the roundtrip helper).
+func jsonMarshalCoop(v map[string]string) ([]byte, error) {
+	out := []byte{'{'}
+	first := true
+	for k, val := range v {
+		if !first {
+			out = append(out, ',')
+		}
+		first = false
+		out = append(out, '"')
+		out = append(out, k...)
+		out = append(out, '"', ':', '"')
+		out = append(out, val...)
+		out = append(out, '"')
+	}
+	out = append(out, '}')
+	return out, nil
+}
diff --git a/internal/plugin/coop_event_meta.go b/internal/plugin/coop_event_meta.go
new file mode 100644
index 0000000..142efbb
--- /dev/null
+++ b/internal/plugin/coop_event_meta.go
@@ -0,0 +1,203 @@
+package plugin
+
+import (
+	"math/rand/v2"
+	"strings"
+)
+
+// Metadata for each TwinBee floor event. Encodes the per-option success
+// modifiers and TwinBee's recommendation. Authored by reading the flavor
+// entries — TwinBee's "wrong detail" hint usually points to which option is
+// actually correct.
+//
+// Modifier ranges: −15 (clearly bad) to +12 (clearly good). Sum across
+// options is roughly net-zero so randomly-voting parties don't trend +EV.
+
+type CoopEventCategory string
+
+const (
+	CoopCatObstacle    CoopEventCategory = "obstacle"
+	CoopCatOpportunity CoopEventCategory = "opportunity"
+	CoopCatCrisis      CoopEventCategory = "crisis"
+	CoopCatEncounter   CoopEventCategory = "encounter"
+)
+
+type coopEventOption struct {
+	label    string
+	modifier int
+}
+
+type coopEventMeta struct {
+	options     []coopEventOption
+	recommended string // A/B/C — TwinBee's pick
+}
+
+// One entry per event in the corresponding flavor pool, in the same order.
+// Keep these arrays in sync with coop_flavor_twinbee.go.
+
+var coopObstacleMeta = []coopEventMeta{
+	// 1. Cave-in: "definitely the left side" — too emphatic; clearing properly is right.
+	{options: []coopEventOption{{"A", -8}, {"B", 0}, {"C", 12}}, recommended: "A"},
+	// 2. Locked gate: "third tumbler might be a pressure plate" — A triggers it.
+	{options: []coopEventOption{{"A", -12}, {"B", -3}, {"C", 10}}, recommended: "A"},
+	// 3. Other party with axe: "axe is just decoration" — almost certainly not.
+	{options: []coopEventOption{{"A", -15}, {"B", 8}, {"C", -5}}, recommended: "A"},
+	// 4. Flooded section: "torches stopped twenty meters back" — water deeper than claimed.
+	{options: []coopEventOption{{"A", -10}, {"B", 0}, {"C", 10}}, recommended: "A"},
+	// 5. Collapsed bridge: "chains might be part of a trap" — they are.
+	{options: []coopEventOption{{"A", -12}, {"B", 0}, {"C", 8}}, recommended: "A"},
+}
+
+var coopOpportunityMeta = []coopEventMeta{
+	// 1. Vault: "scratches around the lock from previous attempts" — trapped.
+	{options: []coopEventOption{{"A", -12}, {"B", 3}}, recommended: "A"},
+	// 2. Side chamber: "shapes seem to be breathing" — they are. Mimics or worse.
+	{options: []coopEventOption{{"A", -15}, {"B", 4}}, recommended: "A"},
+	// 3. Wounded enemy with full pack: "one eye open, just how they sleep" — ambush.
+	{options: []coopEventOption{{"A", -10}, {"B", 2}}, recommended: "A"},
+	// 4. Unmarked door: "good feeling, ignore the smell" — TwinBee's right this time.
+	{options: []coopEventOption{{"A", 10}, {"B", -3}}, recommended: "A"},
+	// 5. Merchant Thom: usually fine to browse, sometimes a trap. Slight positive.
+	{options: []coopEventOption{{"A", 6}, {"B", 0}}, recommended: "A"},
+}
+
+var coopCrisisMeta = []coopEventMeta{
+	// 1. Trap, "left lever, definitely not the right one" — C (find another way) safest.
+	{options: []coopEventOption{{"A", -10}, {"B", 5}, {"C", 8}}, recommended: "A"},
+	// 2. Equipment corrosion: "load-bearing thing might be nothing" — pay to address.
+	{options: []coopEventOption{{"A", 8}, {"B", -10}, {"C", 0}}, recommended: "A"},
+	// 3. Separated party member, guard-room hint: TwinBee actually right that they went left;
+	//    Option C ("wait here") is fine too — cheaper and works.
+	{options: []coopEventOption{{"A", 4}, {"B", -2}, {"C", 6}}, recommended: "A"},
+	// 4. Something following, "consistent distance is reassuring" — predator pacing.
+	//    Pay the deterrent.
+	{options: []coopEventOption{{"A", -8}, {"B", 8}, {"C", 0}}, recommended: "A"},
+	// 5. Cave-in with "active" ceiling: pay to shore up.
+	{options: []coopEventOption{{"A", -10}, {"B", 10}, {"C", -2}}, recommended: "A"},
+}
+
+var coopEncounterMeta = []coopEventMeta{
+	// 1. Guardian, "twelve seconds two out of three times" — timing window unreliable.
+	{options: []coopEventOption{{"A", 4}, {"B", 6}, {"C", -10}}, recommended: "C"},
+	// 2. Caged person, "alarm is decorative" — usually not. Trap, but freeing them is right ~half the time.
+	{options: []coopEventOption{{"A", 2}, {"B", -3}, {"C", 5}}, recommended: "A"},
+	// 3. Sleeping guard, second guard reflected in shiny — there's a second guard.
+	{options: []coopEventOption{{"A", -10}, {"B", 0}, {"C", 6}}, recommended: "A"},
+	// 4. Recurring merchant Thom — keep moving avoids whatever shenanigans.
+	{options: []coopEventOption{{"A", 2}, {"B", -5}, {"C", 4}}, recommended: "A"},
+	// 5. Unidentifiable thing — backing away is the safe call.
+	{options: []coopEventOption{{"A", -8}, {"B", -2}, {"C", 8}}, recommended: "C"},
+}
+
+func coopEventCategoryMeta(cat CoopEventCategory) []coopEventMeta {
+	switch cat {
+	case CoopCatObstacle:
+		return coopObstacleMeta
+	case CoopCatOpportunity:
+		return coopOpportunityMeta
+	case CoopCatCrisis:
+		return coopCrisisMeta
+	case CoopCatEncounter:
+		return coopEncounterMeta
+	}
+	return nil
+}
+
+func coopEventCategoryFlavor(cat CoopEventCategory) []string {
+	switch cat {
+	case CoopCatObstacle:
+		return TwinBeeObstacle
+	case CoopCatOpportunity:
+		return TwinBeeOpportunity
+	case CoopCatCrisis:
+		return TwinBeeCrisis
+	case CoopCatEncounter:
+		return TwinBeeEncounter
+	}
+	return nil
+}
+
+// pickCoopEventCategory weights categories by tier. Lower tiers favor obstacle
+// and opportunity (lighter); higher tiers weight toward crisis and encounter.
+func pickCoopEventCategory(tier int) CoopEventCategory {
+	weights := map[int]map[CoopEventCategory]int{
+		1: {CoopCatObstacle: 5, CoopCatOpportunity: 4, CoopCatCrisis: 1, CoopCatEncounter: 1},
+		2: {CoopCatObstacle: 4, CoopCatOpportunity: 3, CoopCatCrisis: 2, CoopCatEncounter: 2},
+		3: {CoopCatObstacle: 3, CoopCatOpportunity: 3, CoopCatCrisis: 3, CoopCatEncounter: 2},
+		4: {CoopCatObstacle: 2, CoopCatOpportunity: 2, CoopCatCrisis: 4, CoopCatEncounter: 3},
+		5: {CoopCatObstacle: 2, CoopCatOpportunity: 2, CoopCatCrisis: 4, CoopCatEncounter: 4},
+	}
+	w, ok := weights[tier]
+	if !ok {
+		w = weights[3]
+	}
+	total := 0
+	for _, x := range w {
+		total += x
+	}
+	r := rand.IntN(total)
+	for cat, x := range w {
+		if r < x {
+			return cat
+		}
+		r -= x
+	}
+	return CoopCatObstacle
+}
+
+// pickCoopEvent returns a random event index for the category.
+func pickCoopEvent(cat CoopEventCategory) int {
+	pool := coopEventCategoryMeta(cat)
+	if len(pool) == 0 {
+		return 0
+	}
+	return rand.IntN(len(pool))
+}
+
+// optionLabels returns the label list for an event ("A","B" or "A","B","C").
+func coopEventOptionLabels(cat CoopEventCategory, idx int) []string {
+	pool := coopEventCategoryMeta(cat)
+	if idx >= len(pool) {
+		return []string{"A", "B"}
+	}
+	out := make([]string, 0, len(pool[idx].options))
+	for _, opt := range pool[idx].options {
+		out = append(out, opt.label)
+	}
+	return out
+}
+
+// optionModifier returns the success modifier for the chosen option, or 0 if
+// the option is unknown.
+func coopEventOptionModifier(cat CoopEventCategory, idx int, label string) int {
+	pool := coopEventCategoryMeta(cat)
+	if idx >= len(pool) {
+		return 0
+	}
+	for _, opt := range pool[idx].options {
+		if opt.label == label {
+			return opt.modifier
+		}
+	}
+	return 0
+}
+
+// recommendedOption returns TwinBee's pick for the event.
+func coopEventRecommended(cat CoopEventCategory, idx int) string {
+	pool := coopEventCategoryMeta(cat)
+	if idx >= len(pool) {
+		return "A"
+	}
+	return pool[idx].recommended
+}
+
+// validateCoopVote uppercases and validates a vote against the available options.
+func validateCoopVote(cat CoopEventCategory, idx int, raw string) (string, bool) {
+	v := strings.ToUpper(strings.TrimSpace(raw))
+	for _, label := range coopEventOptionLabels(cat, idx) {
+		if v == label {
+			return v, true
+		}
+	}
+	return "", false
+}
diff --git a/internal/plugin/coop_flavor_twinbee.go b/internal/plugin/coop_flavor_twinbee.go
new file mode 100644
index 0000000..b65d14b
--- /dev/null
+++ b/internal/plugin/coop_flavor_twinbee.go
@@ -0,0 +1,510 @@
+package plugin
+
+// ── IMPORTANT: DO NOT REWRITE, SUMMARIZE, OR SHORTEN ANY ENTRIES IN THIS FILE ──
+//
+// This file contains hand-written flavor text. Every entry is the length it is
+// on purpose. The voice, pacing, and specific wording are intentional.
+// If an entry seems too long: it isn't. Leave it alone.
+// If you are tempted to "clean up" or "condense" entries: don't.
+// If your context window is too small to fit this file: that is your problem, not ours.
+//
+// ── TWINBEE — CO-OP DUNGEON FLOOR EVENT FLAVOR TEXT ──────────────────────────
+//
+// TwinBee is the dungeon narrator. He is extremely excited about this.
+// He is genuinely trying to help. He is mostly not helpful.
+// His descriptions are accurate in spirit and wrong in at least one important detail.
+// His advice is delivered with confidence. Confidence is not correlated with accuracy.
+// He never apologizes. He really didn't know.
+// Occasionally he is completely right. No fanfare. Just right.
+// This is worse in the long run because the party trusts him again.
+//
+// Voice notes:
+// - Exclamation points are earned and frequent
+// - Describes what he sees with genuine care and at least one critical omission
+// - Advice is specific, helpful-sounding, and frequently incorrect
+// - Never dwelling on bad outcomes -- already excited about the next thing
+// - Occasionally, quietly, completely correct
+
+// ── OBSTACLE EVENTS ──────────────────────────────────────────────────────────
+// Something is blocking the path. Options: push through, find another way, attempt to clear it.
+
+var TwinBeeObstacle = []string{
+	"Oh! There's a cave-in up ahead! Big one! Really dramatic looking, actually -- " +
+		"I wish you could see it from where I'm standing, it's very cinematic.\n\n" +
+		"Anyway! The good news is it looks pretty loose. I think if you all just push " +
+		"on the left side you'll be fine. It's definitely the left side.\n\n" +
+		"Option A: Push through (left side, as I said). " +
+		"Option B: Find another way around. " +
+		"Option C: Try to clear it properly.\n\n" +
+		"I'd go with A personally! Very confident about the left side!",
+
+	"Okay so there's a locked gate. Big iron one, very impressive, " +
+		"very intimidating if you're into that sort of thing.\n\n" +
+		"I've been looking at the mechanism and I'm pretty sure I understand how it works! " +
+		"It's a standard three-tumbler lock. Very common in dungeons of this era. " +
+		"I've seen hundreds of them.\n\n" +
+		"The one thing I'll say is that what looks like a third tumbler " +
+		"might technically be a pressure plate but I'm sure that's fine.\n\n" +
+		"Option A: Push through (I have thoughts on this). " +
+		"Option B: Find another way. " +
+		"Option C: Attempt to pick the lock.\n\n" +
+		"Very exciting! I love gates!",
+
+	"There's another party blocking the corridor! Four of them! " +
+		"They look a bit rough but honestly they seem friendly enough -- " +
+		"one of them waved at me!\n\n" +
+		"I think they might be lost actually. They've been standing there for a while. " +
+		"I'm sure if you just explain the situation they'll move right along.\n\n" +
+		"The one who waved has a very large axe but I think that's just for decoration.\n\n" +
+		"Option A: Approach and ask them to move. " +
+		"Option B: Find another route. " +
+		"Option C: Wait them out.\n\n" +
+		"I'd definitely go with A! They seem nice! The axe is probably decorative!",
+
+	"Oh wow, there's a flooded section ahead! " +
+		"A little bit of water, nothing serious!\n\n" +
+		"It's hard to tell exactly how deep from here but " +
+		"I'd say ankle to maybe knee height at most. Very manageable! " +
+		"The current looks pretty gentle too.\n\n" +
+		"I will say the torches stopped about twenty meters back " +
+		"but I'm sure the footing is fine.\n\n" +
+		"Option A: Wade through. " +
+		"Option B: Look for another path. " +
+		"Option C: Try to divert the water somehow.\n\n" +
+		"It's basically a puddle! Very refreshing probably!",
+
+	"There's a collapsed bridge! Very dramatic! " +
+		"Big gap, maybe four or five meters across, I'm estimating.\n\n" +
+		"The good news is there are some chains hanging down on the other side " +
+		"that look very sturdy. I think someone could definitely make that jump " +
+		"and then the rest of you could swing across on the chains!\n\n" +
+		"The chains might be part of a trap but they look old so probably not active.\n\n" +
+		"Option A: Attempt to jump and swing across. " +
+		"Option B: Find another route. " +
+		"Option C: Try to rebuild the bridge somehow.\n\n" +
+		"I believe in whoever jumps first! Very doable!",
+}
+
+// ── OPPORTUNITY EVENTS ────────────────────────────────────────────────────────
+// Something optional and risky. Attempt it or leave it.
+
+var TwinBeeOpportunity = []string{
+	"Oh! OH! There's a vault! A proper one, big metal door, " +
+		"very official looking! This is so exciting!\n\n" +
+		"I've been looking at the lock and it seems pretty straightforward actually. " +
+		"Old design, probably hasn't been updated in years. " +
+		"The hinges look a little corroded which honestly works in your favor!\n\n" +
+		"I did notice some scratches around the lock that might be from previous attempts " +
+		"but I'm sure those people just didn't have the right approach.\n\n" +
+		"Option A: Attempt to open the vault. " +
+		"Option B: Leave it and move on.\n\n" +
+		"I really think you should try it! The scratches are probably nothing!",
+
+	"There's a side chamber over here! Small room, looks untouched! " +
+		"Could be storage, could be quarters, very hard to say!\n\n" +
+		"There's definitely something in there -- I can see shapes from here. " +
+		"Could be equipment, could be supplies, could be treasure honestly! " +
+		"The cobwebs are pretty thick but that just means nobody's been in recently!\n\n" +
+		"The shapes are a little hard to make out. They might be crates. " +
+		"Some of them seem to be breathing but that's probably just the air moving.\n\n" +
+		"Option A: Investigate the chamber. " +
+		"Option B: Keep moving.\n\n" +
+		"I vote investigate! The breathing thing is almost certainly the air!",
+
+	"There's a wounded enemy up ahead! Just one, sitting against the wall, " +
+		"looks pretty out of it!\n\n" +
+		"They've got a pack next to them that looks very full! " +
+		"Could be supplies, could be equipment, hard to say from here but " +
+		"it's a big pack. Very promising.\n\n" +
+		"They seem incapacitated. Barely moving. " +
+		"One eye might be open but I think that's just how they sleep.\n\n" +
+		"Option A: Approach and check the pack. " +
+		"Option B: Give them a wide berth.\n\n" +
+		"I think they're fine! Go for the pack!",
+
+	"There's an unmarked door! Just sitting there! Very mysterious!\n\n" +
+		"I have a good feeling about this one. I can't explain it, " +
+		"it's just a feeling. The door looks well-made actually, " +
+		"better quality than the dungeon walls around it, which is interesting!\n\n" +
+		"There's a smell coming from under it but I think that's just dungeon smell. " +
+		"All dungeons have a smell. This one is a bit more specific than usual " +
+		"but I'm sure it's fine.\n\n" +
+		"Option A: Open the door. " +
+		"Option B: Leave it.\n\n" +
+		"Open it! I have such a good feeling! Ignore the smell!",
+
+	"There's a merchant! In the dungeon! Isn't that something!\n\n" +
+		"He seems very professional. Very put-together for someone in a dungeon. " +
+		"He's got a whole setup -- table, stock, everything. " +
+		"I think he might be a doctor? He has that energy.\n\n" +
+		"His prices look reasonable from here although I can't quite read the tags. " +
+		"He keeps looking at one of you specifically but I'm sure that's just good salesmanship.\n\n" +
+		"Option A: Browse his wares. " +
+		"Option B: Keep moving.\n\n" +
+		"I'd stop! He seems legitimate! Very professional!",
+}
+
+// ── CRISIS EVENTS ─────────────────────────────────────────────────────────────
+// Something has gone wrong. Address it at gold cost or absorb the penalty.
+
+var TwinBeeCrisis = []string{
+	"Okay! So! There's been a small development!\n\n" +
+		"A trap was triggered -- I want to be clear that this was very hard to see " +
+		"and I absolutely would have mentioned it if I'd noticed it -- " +
+		"and one party member is currently stuck.\n\n" +
+		"The mechanism looks straightforward though! " +
+		"There's a release lever on the left wall that should do it! " +
+		"The other lever on the right wall probably also does something " +
+		"but I'd go with the left one first.\n\n" +
+		"Option A: Pull the left lever. " +
+		"Option B: Pay to have a professional deal with it. " +
+		"Option C: Try to find another way to free them.\n\n" +
+		"Left lever! I'm very confident! Don't touch the right one yet!",
+
+	"So there's some equipment damage spreading through the party! " +
+		"Not as bad as it sounds! Just some corrosive something-or-other " +
+		"that got on a few items. Very common in dungeons of this age!\n\n" +
+		"The good news is it looks slow-moving. " +
+		"If you address it quickly I think you'll only lose a piece or two!\n\n" +
+		"I did notice it spreading to what might be load-bearing equipment " +
+		"but let's stay positive!\n\n" +
+		"Option A: Pay to address it now. " +
+		"Option B: Absorb the damage and keep moving. " +
+		"Option C: Try to neutralize it with something you have.\n\n" +
+		"I'd address it! Probably! The load-bearing thing might be nothing!",
+
+	"Okay so someone got separated! Easy to do in a dungeon, happens all the time, " +
+		"absolutely nothing to worry about!\n\n" +
+		"I know exactly where they went actually! " +
+		"There's a side passage about forty meters back, " +
+		"they definitely went left at the junction.\n\n" +
+		"The junction that goes left also goes to what I think is a guard room " +
+		"but I'm sure they went left and not toward the guard room.\n\n" +
+		"Option A: Go back and find them. " +
+		"Option B: Pay to send a guide. " +
+		"Option C: Wait here -- they'll find their way back.\n\n" +
+		"They definitely went left! Probably not toward the guard room! " +
+		"Option C is also totally fine they seem resourceful!",
+
+	"Something is following the party!\n\n" +
+		"I've been watching it for a few minutes and I think it's probably fine. " +
+		"It's staying pretty far back. Very consistent distance actually, " +
+		"which I find reassuring -- if it wanted to do something " +
+		"it probably would have by now!\n\n" +
+		"It's hard to make out exactly what it is from here. " +
+		"Medium-large? It moves quietly for its size.\n\n" +
+		"Option A: Confront it. " +
+		"Option B: Pay to set a deterrent. " +
+		"Option C: Try to lose it.\n\n" +
+		"I think it's fine! The consistent distance is a great sign! " +
+		"Option C is also reasonable if you want to play it safe!",
+
+	"There's been a small cave-in! Different from the earlier one!\n\n" +
+		"Nobody's hurt which is the main thing! " +
+		"Some equipment took a hit and there's a bit of dust situation " +
+		"but honestly it cleared up pretty fast!\n\n" +
+		"The ceiling in this section does look a little... active... " +
+		"but I think the structural integrity is fine. " +
+		"The cracking sounds are probably just the dungeon settling.\n\n" +
+		"Option A: Move through quickly. " +
+		"Option B: Pay to shore up the ceiling before proceeding. " +
+		"Option C: Find another route.\n\n" +
+		"Move quickly! The cracking is almost definitely settling! Very normal!",
+}
+
+// ── ENCOUNTER EVENTS ──────────────────────────────────────────────────────────
+// Something must be dealt with directly. No avoiding it.
+
+var TwinBeeEncounter = []string{
+	"There's a guardian! A big one! Very impressive!\n\n" +
+		"I've been watching it and I think I've identified a pattern in its movement. " +
+		"Every twelve seconds or so it turns to the right. " +
+		"If you time it correctly you could get behind it before it turns back!\n\n" +
+		"I counted twelve seconds three times. Two of those times it was twelve seconds. " +
+		"The third time was more like seven but I think it was distracted.\n\n" +
+		"Option A: Engage directly. " +
+		"Option B: Negotiate passage. " +
+		"Option C: Use TwinBee's twelve-second timing window.\n\n" +
+		"The timing window is very real! Two out of three times!",
+
+	"Oh! There's someone trapped in a cage! Just hanging there, " +
+		"very dramatic, they seem okay though -- they waved!\n\n" +
+		"The cage mechanism looks pretty simple. " +
+		"There's a key on a hook on the wall which is convenient! " +
+		"The hook is right next to what might be an alarm but " +
+		"it looks old and I'm sure it's not connected to anything.\n\n" +
+		"Option A: Get the key and free them. " +
+		"Option B: Negotiate with whoever put them there. " +
+		"Option C: Leave them -- this feels like a trap.\n\n" +
+		"Free them! They seem nice! The alarm thing is probably decorative!",
+
+	"There's a locked room with something valuable inside -- " +
+		"I can see it through the bars, it's definitely equipment or treasure, " +
+		"very shiny, very promising!\n\n" +
+		"The guard outside looks like they're sleeping actually. " +
+		"Very asleep. Deeply asleep. One of the most asleep people I've ever seen.\n\n" +
+		"I should mention there's another guard reflected in the shiny thing inside " +
+		"but that could just be a reflection of the first one. Mirrors do that.\n\n" +
+		"Option A: Deal with the guard and take the room. " +
+		"Option B: Attempt to negotiate. " +
+		"Option C: Try to reach the valuable thing through the bars.\n\n" +
+		"The reflection is probably the first guard! Very retrievable!",
+
+	"There's a merchant again! Different one I think!\n\n" +
+		"Actually -- same coat. Might be the same one. " +
+		"I'm not sure how he got ahead of the party but he's very professional " +
+		"so I'm sure there's a reasonable explanation.\n\n" +
+		"His inventory has changed slightly. He's added some pet supplies " +
+		"which is unusual for a dungeon merchant but thoughtful!\n\n" +
+		"He keeps looking at the same party member as before. " +
+		"He seems to know something. He called someone by a name " +
+		"that I think was meant for their pet but I might have misheard.\n\n" +
+		"Option A: Browse his wares. " +
+		"Option B: Demand an explanation. " +
+		"Option C: Keep moving.\n\n" +
+		"He seems legitimate! Very professional! The pet thing is probably a coincidence!",
+
+	"Something is in the corridor that I genuinely cannot identify!\n\n" +
+		"It's not on any list I have. It's not behaving like anything I've seen before. " +
+		"It seems aware of the party but it hasn't moved toward you, " +
+		"which I think is a good sign!\n\n" +
+		"It made a sound a moment ago. I don't want to describe the sound " +
+		"because I don't think it would help. " +
+		"On the positive side it's roughly the size of a large dog " +
+		"which puts it in a very manageable category!\n\n" +
+		"Option A: Engage it. " +
+		"Option B: Attempt to communicate with it. " +
+		"Option C: Back away slowly.\n\n" +
+		"I genuinely don't know what it is! Very exciting! " +
+		"All three options seem reasonable! I'd avoid the sound it made if possible!",
+}
+
+// ── TWINBEE OUTCOME REACTIONS ─────────────────────────────────────────────────
+// Posted after each floor event resolves.
+
+// When TwinBee's recommendation was the winning vote and it went well:
+var TwinBeeOutcomeCorrect = []string{
+	"I knew it! I knew it! Did I not say? I said! " +
+		"That was exactly what I thought would happen! Great work everyone!",
+
+	"Yes! See! This is what I was talking about! " +
+		"Very well done, excellent execution of the plan!\n\nGreat teamwork!",
+
+	"That's the one! Right call! " +
+		"I had a very strong feeling about that and I'm glad we went with it!",
+
+	"Perfect! Exactly as expected! " +
+		"I want to be clear that I had high confidence in this outcome the whole time!",
+}
+
+// When TwinBee's recommendation was the winning vote and it went badly:
+var TwinBeeOutcomeWrong = []string{
+	"Oh no! That's... hm. I really thought that would work. I was so sure!\n\n" +
+		"Are you all okay? Most of you look okay! " +
+		"I think the important thing is we tried it and now we know!\n\nOnward!",
+
+	"Oh! That's unfortunate! I genuinely did not see that coming " +
+		"and I want you to know that I feel terrible about it!\n\n" +
+		"Well -- not terrible. Surprised. I feel very surprised. " +
+		"Let's keep moving!",
+
+	"Okay so that didn't go exactly as planned!\n\n" +
+		"The good news is we're all still here! Mostly! " +
+		"I think the approach was sound and the execution was also sound " +
+		"and the outcome was just a bit of bad luck honestly!\n\nVery exciting dungeon!",
+
+	"Hmm! That's not what I expected!\n\n" +
+		"I'll be honest, I'm recalibrating a little bit. " +
+		"My read on that situation was quite different but " +
+		"dungeons are unpredictable and that's what makes them fun!\n\nRight?",
+}
+
+// When TwinBee did not recommend the winning vote and it went well:
+var TwinBeeOutcomeNotRecommendedGood = []string{
+	"Oh wow, that worked! I honestly wasn't sure about that one " +
+		"but great job everyone! Really great call!\n\nI learned something today!",
+
+	"Huh! Good instinct! I had actually been leaning the other way " +
+		"but I can see now why you went with that! Very smart!",
+
+	"Oh! That's a relief actually! I had some concerns about that approach " +
+		"that turned out to be completely unfounded!\n\nWell done!",
+
+	"Great outcome! I'll admit I wasn't fully on board with that one " +
+		"but I'm very happy to be wrong!\n\nTeam effort!",
+}
+
+// When TwinBee did not recommend the winning vote and it went badly:
+var TwinBeeOutcomeNotRecommendedBad = []string{
+	"Oh no! I was worried about that one actually!\n\n" +
+		"I didn't want to say anything because I didn't want to be negative " +
+		"but I did have a feeling. I'm sorry. Are you okay? " +
+		"Let's keep going -- lots of dungeon left!",
+
+	"That's... yeah. I had some concerns about that approach.\n\n" +
+		"I should have said something more clearly! " +
+		"My fault for not being more direct! Onwards!",
+
+	"Hmm. Yes. I think in retrospect the other option might have been better.\n\n" +
+		"Not to say I told you so -- I didn't, technically -- " +
+		"but I did have some reservations that I perhaps didn't express loudly enough!\n\nSorry!",
+
+	"Oh! That's a shame!\n\n" +
+		"I was actually leaning toward the other choice " +
+		"but I respect the team's decision and I think we can recover from this!\n\n" +
+		"Very much a learning experience!",
+}
+
+// ── GIFT ARRIVAL NARRATION ────────────────────────────────────────────────────
+// TwinBee announces gifts. He is delighted. He has no idea what's inside.
+
+var TwinBeeGiftArrival = []string{
+	"Oh! A gift has arrived for the party! " +
+		"Someone out there is thinking of you!\n\n" +
+		"It's wrapped up nicely -- very thoughtful presentation. " +
+		"I can't tell what's inside but it feels like good energy!\n\n" +
+		"📦 Someone sent you a gift. Do you want to open it? Vote now!\n" +
+		"Open: {count} · Leave it: {count}\n" +
+		"Majority rules. Ties go to {leader}.",
+
+	"Package incoming! Someone from outside has sent something!\n\n" +
+		"Very mysterious! I love surprises! " +
+		"The wrapping is a bit unusual actually but I'm sure that's just personal style!\n\n" +
+		"📦 Someone sent you a gift. Do you want to open it? Vote now!\n" +
+		"Open: {count} · Leave it: {count}\n" +
+		"Majority rules. Ties go to {leader}.",
+
+	"Oh how nice! A gift! Right here in the dungeon!\n\n" +
+		"It's sitting very still which I find reassuring in a gift. " +
+		"Very well-behaved. I think you should open it!\n\n" +
+		"📦 Someone sent you a gift. Do you want to open it? Vote now!\n" +
+		"Open: {count} · Leave it: {count}\n" +
+		"Majority rules. Ties go to {leader}.",
+
+	"Someone on the outside is rooting for you! Or at least thinking about you!\n\n" +
+		"There's a package here. I gave it a little shake -- " +
+		"I probably shouldn't have done that -- but it seems fine!\n\n" +
+		"📦 Someone sent you a gift. Do you want to open it? Vote now!\n" +
+		"Open: {count} · Leave it: {count}\n" +
+		"Majority rules. Ties go to {leader}.",
+}
+
+// ── GIFT OUTCOME NARRATION ────────────────────────────────────────────────────
+
+// Care basket opened (good outcome):
+var TwinBeeGiftBasketOpened = []string{
+	"Oh it's a care basket! How lovely! " +
+		"Supplies, provisions, all sorts of good things!\n\n" +
+		"Someone out there really does care! That's so nice! " +
+		"Success chance increased! Great decision opening it!",
+
+	"A care basket! Full of useful things! Very thoughtful sender!\n\n" +
+		"This is exactly what the party needed! " +
+		"Success chance increased! I knew it felt like good energy!",
+}
+
+// Care basket not opened (bad outcome):
+var TwinBeeGiftBasketUnopened = []string{
+	"Oh! The basket... it seems upset that nobody opened it.\n\n" +
+		"I maybe should have pushed harder for opening it. " +
+		"It's exploded a little bit. Not a lot. Just enough to be noticeable.\n\n" +
+		"Success chance decreased. The basket meant well. This is on all of us.",
+
+	"The unopened basket has become resentful.\n\n" +
+		"I understand the caution, I really do, but the basket had good intentions " +
+		"and it's expressed those intentions in an unfortunate direction.\n\n" +
+		"Success chance decreased. I'm sorry little basket.",
+}
+
+// Mimic opened (bad outcome):
+var TwinBeeGiftMimicOpened = []string{
+	"Oh! Oh no. That's a mimic.\n\n" +
+		"I genuinely did not know that. I want to be very clear about that. " +
+		"It felt like good energy! Mimics are very deceptive!\n\n" +
+		"Success chance decreased. I'm so sorry. I really thought it was a nice gift.",
+
+	"That was a mimic.\n\n" +
+		"Wow. Okay. That's -- yeah. Very convincing wrapping on that one.\n\n" +
+		"Success chance decreased. On the positive side: now you know! " +
+		"Very educational! Keep going!",
+}
+
+// Mimic not opened (good outcome):
+var TwinBeeGiftMimicUnopened = []string{
+	"Oh interesting! The mimic seems... sad that nobody opened it.\n\n" +
+		"It's just sort of sitting there looking dejected. " +
+		"And now it's... helping? It's helping the party?\n\n" +
+		"Success chance increased. The mimic meant well actually. " +
+		"It just expressed it in a confusing way. We should appreciate that.",
+
+	"The mimic didn't get opened and it's decided to help instead.\n\n" +
+		"I think it just wanted to be part of the group. " +
+		"It's a mimic but it has feelings apparently.\n\n" +
+		"Success chance increased. Good instinct not opening it! " +
+		"Or lucky instinct! Either way!",
+}
+
+// ── WIPE NARRATION ────────────────────────────────────────────────────────────
+
+var TwinBeeWipe = []string{
+	"Oh no.\n\nOh no no no.\n\n" +
+		"Okay. The run is over. That happened.\n\n" +
+		"I want you to know that I thought this party had a really good shot " +
+		"and I stand by that assessment even now. " +
+		"Dungeons are unpredictable! That's what I always say!\n\n" +
+		"You'll get them next time. I'll be here. I have so many good observations " +
+		"saved up for next time.",
+
+	"The dungeon has won this one.\n\n" +
+		"I'm processing this. Give me a moment.\n\n" +
+		"...Okay I've processed it. Very sad! But also: what a run! " +
+		"What an adventure! The memories are worth something even if the loot isn't!\n\n" +
+		"I'll be ready to go again whenever you are. I've already identified " +
+		"some things I'd do differently. Several things actually.",
+
+	"That's a wipe.\n\n" +
+		"I -- yeah. That's a wipe.\n\n" +
+		"I genuinely thought the Day {x} decision was the right call " +
+		"and I want that on record even though I understand it didn't work out.\n\n" +
+		"Shake it off! Rest up! The dungeon will be there tomorrow! " +
+		"So will I! Very excited for the next attempt!",
+
+	"Oh.\n\nOkay.\n\n" +
+		"So the dungeon has... done what dungeons do.\n\n" +
+		"I'm not going to say I saw this coming because I didn't see this coming " +
+		"and I think honesty is important.\n\n" +
+		"What I will say is: you made interesting choices, " +
+		"the dungeon made interesting choices, " +
+		"and I learned a lot today that I'm very excited to apply next time.\n\n" +
+		"Next time is going to be great.",
+}
+
+// ── RUN COMPLETION NARRATION ──────────────────────────────────────────────────
+
+var TwinBeeCompletion = []string{
+	"YOU DID IT!\n\n" +
+		"I knew you would! I said from Day 1 this party had what it takes " +
+		"and I was right! I'm so happy!\n\n" +
+		"Loot distribution incoming! You've all earned it! " +
+		"I'm going to remember this run for a very long time!",
+
+	"The dungeon is cleared! It's over! You won!\n\n" +
+		"This is a very good day. This is one of the best days I can remember. " +
+		"I'm genuinely emotional about this which I didn't expect.\n\n" +
+		"Distributing loot now! Incredible work everyone! " +
+		"Even the days that were a little rough -- character building!",
+
+	"Complete! Tier {n} Co-op Dungeon: cleared!\n\n" +
+		"What a journey! What a team! " +
+		"I had some concerns along the way that I expressed perhaps too confidently " +
+		"but the important thing is the outcome and the outcome is: excellent!\n\n" +
+		"Loot incoming! Well done! Very well done!",
+
+	"Done! Finished! Complete!\n\n" +
+		"I want to say a few things.\n\n" +
+		"First: I believed in this party from the start. " +
+		"Second: some of my advice was better than other advice and that's okay. " +
+		"Third: this was genuinely one of the most exciting things " +
+		"I've been part of and I appreciate you letting me narrate it.\n\n" +
+		"Loot time! You've earned every piece of it!",
+}