zones: make locked doors openable and stop autopilot stalling on them

Locks were fully implemented as pass/fail gates and nothing else. A
Perception or stat check rolls once per (run, edge), seeded so it can't
be reload-scummed — that half shipped in G5, the counterweight never did.
A bad roll simply deleted a branch of the graph for the rest of the run,
worst for a solo low-WIS character who quietly loses routes they never
learn existed. Three changes, one theme: a die roll should not be able to
permanently wall a player.

Party's best stat answers the check. evaluateEdgeLock read only the
acting character's mods, which made a party's rogue and its hired scout
decorative at every lock. Fold the whole roster — Pete included, since
excluding him would make hiring a scout worth less than the coins it
costs — and credit whoever got it open in the fork menu.

Thieves' tools as the escape hatch. A utility item (not a ConsumableDef,
or the fight engine would spend them for you) sold on Luigi's supplies
shelf, consumed by `!zone unlock <n>`. Deliberately not a skeleton key:
tools answer the two dice-driven locks only. A key lock is a quest token,
a level-min lock is progression, a region-clear lock is structure — none
of those are "you rolled badly", so none of them are pickable.

Autopilot picks a route instead of parking. The fork timeout was 8h,
which reads as "the player gets first say" and behaves as "the expedition
stops for a third of a day, at every fork" — a multi-day expedition
crosses a lot of forks. 30m keeps a genuine first say for anyone at the
keyboard. It now ranks by unvisited-then-edge-weight rather than taking
whatever the graph author happened to list first, spends tools when every
route is locked, and backtracks a room when it can't do even that, rather
than idling into the 24h reaper and losing the player days of progress to
a roll they never saw.

Sim A/B, same seeds, 90 runs/arm: 43.3% -> 42.2% clear, a single run
flipping and well inside the documented noise floor. A party+companion+pet
arm runs 31/32 clean through the new roster-folding path.

internal/plugin/adventure_shop.go

@@ -1019,6 +1019,9 @@ func luigiSuppliesView(_ id.UserID, balance float64) string {
 		}
 	}
 
+	sb.WriteString(fmt.Sprintf("**%s** — €%d\n  Opens one dungeon path a failed check closed (`!zone unlock <n>`). Not used in combat.\n\n",
+		thievesToolsName, thievesToolsPrice))
+
 	sb.WriteString("Reply with an item name to buy, or `back` to return.\n")
 	sb.WriteString("Stronger consumables drop from foraging, mining, fishing, and dungeons at T2+.")
 	return sb.String()
@@ -1073,6 +1076,13 @@ func (p *AdventurePlugin) resolveShopSupplyChoice(ctx MessageContext, interactio
 		return p.SendDM(ctx.Sender, "*Luigi nods and gestures toward the main counter.*")
 	}
 
+	// Thieves' tools sit on the supplies shelf but are not a ConsumableDef:
+	// the combat engine scans inventory against that table and would happily
+	// spend them mid-fight. They get their own branch and their own item type.
+	if containsFold(thievesToolsName, reply) || containsFold("thieves tools", reply) {
+		return p.buyThievesTools(ctx, interaction)
+	}
+
 	// Find matching consumable
 	var match *ConsumableDef
 	for i := range consumableDefs {
@@ -1115,6 +1125,34 @@ func (p *AdventurePlugin) resolveShopSupplyChoice(ctx MessageContext, interactio
 		match.Name, consumablePrice, newBalance))
 }
 
+// buyThievesTools sells one set off the supplies shelf. Mirrors the consumable
+// purchase beside it — same session price factor, same 5% pot cut — and leaves
+// the player in the supplies view so they can buy a second.
+func (p *AdventurePlugin) buyThievesTools(ctx MessageContext, interaction *advPendingInteraction) error {
+	price := float64(thievesToolsPrice) * p.shopSessionPriceFactor(ctx.Sender)
+	balance := p.euro.GetBalance(ctx.Sender)
+	if balance < price {
+		p.pending.Store(string(ctx.Sender), interaction)
+		return p.SendDM(ctx.Sender, fmt.Sprintf("You need €%.0f for %s but only have €%.0f.",
+			price, thievesToolsName, balance))
+	}
+	p.euro.Debit(ctx.Sender, price, "shop_thieves_tools")
+	if potCut := int(math.Round(price * 0.05)); potCut > 0 {
+		communityPotAdd(potCut)
+		trackTaxPaid(ctx.Sender, potCut)
+	}
+	_ = addAdvInventoryItem(ctx.Sender, AdvItem{
+		Name:  thievesToolsName,
+		Type:  thievesToolsItemType,
+		Tier:  1,
+		Value: thievesToolsPrice / 2,
+	})
+	p.pending.Store(string(ctx.Sender), interaction)
+	return p.SendDM(ctx.Sender, fmt.Sprintf(
+		"Purchased **%s** for €%.0f. You carry %d.\n💰 Balance: €%.0f\n\nReply with another item name or `back` to return.",
+		thievesToolsName, price, countThievesTools(ctx.Sender), p.euro.GetBalance(ctx.Sender)))
+}
+
 // ── Curios (Magic Items) ────────────────────────────────────────────────────
 
 // curiosStockSize — how many registry magic items Luigi stocks per day.

internal/plugin/dnd_expedition_cmd.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log/slog"
 	"math"
+	"sort"
 	"strconv"
 	"strings"
 	"time"
@@ -843,41 +844,147 @@ func (p *AdventurePlugin) expeditionCmdRun(ctx MessageContext) error {
 // run graph / harvest tally / supplies / threat — same as before, just
 // no streamFlow here. compact==true switches the underlying combat
 // narration into terse mode and auto-resolves elite (not boss) rooms.
-// forkAutoPickTimeout — how long a background fork may sit unanswered
+// forkAutoPickTimeout — how long a background fork may sit unanswered before
-// before the autopilot picks an available route itself. Short enough that
+// the autopilot picks a route itself.
-// the expedition keeps moving rather than idling out to the 24h stale-run
+//
-// reaper; long enough that a player away for the evening still gets first
+// This was 8h, which reads as "the player gets first say" and behaves as "the
-// say on a genuine fork.
+// expedition stops for a third of a day, every fork." A multi-day expedition
-const forkAutoPickTimeout = 8 * time.Hour
+// crosses a lot of forks; at 8h apiece the autopilot spends more of its life
+// parked than walking, and a player who is simply asleep loses a night per
+// branch. 30m keeps a genuine first say for anyone actually at the keyboard and
+// costs an absent player almost nothing.
+const forkAutoPickTimeout = 30 * time.Minute
 
-// autoPickStaleFork commits the first unlocked option of a stale background
+// rankForkOptions orders a fork's options by how much walking them is worth:
-// fork, advancing the run to that node exactly as `!zone go <n>` would
+// somewhere new first, then the fatter edge (Weight is the author's own "this
-// (advanceZoneRunNode + region-transition hook). Returns false — no pick —
+// is the main line" signal), then menu order as the tiebreak so the pick is
-// when every option is locked, so the caller re-emits the prompt and the
+// deterministic. Only unlocked options are returned.
-// run idles on toward the reaper. The choice is logged as a narrative entry
+//
-// so the end-of-day digest can surface the decision the player missed.
+// The old rule was "first unlocked option in the menu", which is edge-authoring
+// order — meaningful to whoever wrote the graph, arbitrary to the player. It
+// walked past unvisited branches to loop through cleared ones often enough to
+// look broken.
+func rankForkOptions(g ZoneGraph, run *DungeonRun, pf *pendingFork) []pendingChoice {
+	weights := map[string]int{}
+	for _, e := range g.outgoingEdges(run.CurrentNode) {
+		weights[e.To] = e.Weight
+	}
+	visited := map[string]bool{}
+	for _, n := range run.VisitedNodes {
+		visited[n] = true
+	}
+
+	open := make([]pendingChoice, 0, len(pf.Options))
+	for _, o := range pf.Options {
+		if o.Unlocked {
+			open = append(open, o)
+		}
+	}
+	sort.SliceStable(open, func(i, j int) bool {
+		vi, vj := visited[open[i].To], visited[open[j].To]
+		if vi != vj {
+			return !vi // unvisited first
+		}
+		if wi, wj := weights[open[i].To], weights[open[j].To]; wi != wj {
+			return wi > wj
+		}
+		return open[i].Index < open[j].Index
+	})
+	return open
+}
+
+// autoPickStaleFork commits a stale background fork, advancing the run exactly
+// as `!zone go <n>` would (advanceZoneRunNode + region-transition hook). The
+// choice is logged as a narrative entry so the end-of-day digest can surface
+// the decision the player missed.
+//
+// When every route is locked it does not give up: it spends a set of thieves'
+// tools if the party is carrying any and one of the locks is the pickable kind.
+// Returns false only when there is genuinely nothing it can do — the caller
+// then backtracks rather than idling the expedition into the 24h reaper.
 func (p *AdventurePlugin) autoPickStaleFork(exp *Expedition, run *DungeonRun, pf *pendingFork) bool {
-	var chosen *pendingChoice
+	g, _ := loadZoneGraph(run.ZoneID)
-	for i := range pf.Options {
+
-		if pf.Options[i].Unlocked {
+	ranked := rankForkOptions(g, run, pf)
-			chosen = &pf.Options[i]
+	note := "autopilot took the most promising path"
-			break
+	if len(ranked) == 0 {
+		picked, ok := p.autoPickWithTools(run, pf)
+		if !ok {
+			return false
 		}
+		ranked = []pendingChoice{picked}
+		note = "autopilot spent " + thievesToolsName + " on the only way forward"
 	}
-	if chosen == nil {
+	chosen := ranked[0]
-		return false // nothing unlocked — leave it for the player / reaper
+
-	}
 	if _, err := advanceZoneRunNode(run.RunID, chosen.To); err != nil {
 		slog.Warn("expedition: auto-pick stale fork",
 			"user", run.UserID, "run", run.RunID, "err", err)
 		return false
 	}
-	g, _ := loadZoneGraph(run.ZoneID)
 	fireGraphRegionTransition(run.UserID, g.Nodes[run.CurrentNode], g.Nodes[chosen.To])
 	if exp != nil {
 		_ = appendExpeditionLog(exp.ID, exp.CurrentDay, "narrative",
-			fmt.Sprintf("autopilot took an available path after %dh idle at the fork: %s",
+			fmt.Sprintf("%s: %s", note, chosen.Label), "")
-				int(forkAutoPickTimeout.Hours()), chosen.Label), "")
+	}
+	return true
+}
+
+// autoPickWithTools spends one set of thieves' tools to open a fork where every
+// route is locked, so a bad Perception roll can't quietly end an expedition the
+// player paid days into. It only ever fires when there is no free route left —
+// the player's tools are their own, and the autopilot does not get to burn them
+// for convenience.
+func (p *AdventurePlugin) autoPickWithTools(run *DungeonRun, pf *pendingFork) (pendingChoice, bool) {
+	owner := id.UserID(run.UserID)
+	toolID, ok := findThievesTools(owner)
+	if !ok {
+		return pendingChoice{}, false
+	}
+	for i := range pf.Options {
+		if pf.Options[i].Unlocked || !pickableLock(pf.Options[i].Lock) {
+			continue
+		}
+		if err := removeAdvInventoryItem(toolID); err != nil {
+			slog.Warn("expedition: autopilot tools spend", "user", run.UserID, "err", err)
+			return pendingChoice{}, false
+		}
+		pf.Options[i].Unlocked = true
+		pf.Options[i].Reason = "opened with " + thievesToolsName
+		_ = writePendingFork(run.RunID, *pf)
+		return pf.Options[i], true
+	}
+	return pendingChoice{}, false
+}
+
+// backtrackFromDeadFork walks the run back one room when a fork has no route
+// the autopilot can take and no tools to buy one with. Without this the run
+// simply sits there until the 24h stale reaper ends the expedition — a player
+// losing days of progress to a die roll they never saw and could not answer.
+// Backtracking at least returns them to a room with other exits.
+//
+// Returns false at the entry node, where there is nowhere behind to go.
+func (p *AdventurePlugin) backtrackFromDeadFork(exp *Expedition, run *DungeonRun) bool {
+	idx := pathIndexOf(run.VisitedNodes, run.CurrentNode)
+	if idx <= 0 {
+		return false
+	}
+	target := run.VisitedNodes[idx-1]
+
+	// Clear the fork first: it belongs to the node being left, and both
+	// `!zone advance` and `!zone go` would otherwise resolve a prompt pointing
+	// at a room the party is no longer standing in.
+	if err := clearPendingFork(run.RunID); err != nil {
+		slog.Warn("expedition: backtrack clear fork", "run", run.RunID, "err", err)
+		return false
+	}
+	if _, err := revisitZoneRun(run.RunID, target, run.VisitedNodes); err != nil {
+		slog.Warn("expedition: backtrack from dead fork", "run", run.RunID, "err", err)
+		return false
+	}
+	if exp != nil {
+		_ = appendExpeditionLog(exp.ID, exp.CurrentDay, "narrative",
+			"every way on was sealed — the party doubled back", "")
 	}
 	return true
 }
@@ -903,9 +1010,19 @@ func (p *AdventurePlugin) runAutopilotWalk(ctx MessageContext, maxRooms int, com
 	// (unlocked) route and keep walking instead of stalling out.
 	if run, rerr := getActiveZoneRun(ctx.Sender); rerr == nil && run != nil {
 		if pf, derr := decodePendingFork(run.NodeChoices); derr == nil && pf != nil {
-			picked := compact &&
+			stale := compact && time.Since(run.LastActionAt) > forkAutoPickTimeout
-				time.Since(run.LastActionAt) > forkAutoPickTimeout &&
+			picked := stale && p.autoPickStaleFork(exp, run, pf)
-				p.autoPickStaleFork(exp, run, pf)
+			// Stale and nothing takeable: every route locked, no tools. Back out
+			// one room rather than sitting here until the 24h reaper ends an
+			// expedition the player may be days into. The backtrack clears the
+			// fork, so the next tick walks from the previous room normally.
+			if stale && !picked && p.backtrackFromDeadFork(exp, run) {
+				return autopilotWalkResult{
+					finalMsg: "🔒 Every way on was sealed. The party doubled back to look for another line.",
+					rooms:    0,
+					reason:   stopFork,
+				}
+			}
 			if !picked {
 				zone := zoneOrFallback(run.ZoneID)
 				return autopilotWalkResult{

internal/plugin/dnd_zone_cmd.go

@@ -53,6 +53,9 @@ func (p *AdventurePlugin) handleDnDZoneCmd(ctx MessageContext, args string) erro
 		// fork pending) the handler short-circuits with a friendly
 		// message — see zoneCmdGo for the full surface.
 		return p.zoneCmdGo(ctx, rest)
+	case "unlock", "pick", "force":
+		// Spend thieves' tools on a fork option a failed check closed.
+		return p.zoneCmdUnlock(ctx, rest)
 	case "status", "info":
 		return p.zoneCmdStatus(ctx)
 	case "map", "m":
@@ -83,6 +86,7 @@ func zoneHelpText() string {
 	b.WriteString("`!zone map` — show the room layout\n")
 	b.WriteString("`!zone advance` — resolve the current room and move on\n")
 	b.WriteString("`!zone go <n>` — at a fork, take path #n\n")
+	b.WriteString("`!zone unlock <n>` — spend thieves' tools to open a path you couldn't\n")
 	b.WriteString("`!revisit <n>` — walk back to a room you've already cleared\n")
 	b.WriteString("`!zone abandon` — end the active run (no rewards)\n")
 	b.WriteString("`!zone taunt` — poke TwinBee (they'll remember)\n")

internal/plugin/dnd_zone_cmd_graph.go

@@ -188,6 +188,17 @@ func (p *AdventurePlugin) zoneCmdGo(ctx MessageContext, rest string) error {
 	if cerr != nil {
 		return p.SendDM(ctx.Sender, cerr.Error())
 	}
+	return p.commitForkChoice(ctx, run, chosen, "")
+}
+
+// commitForkChoice advances the run onto an already-validated fork option and
+// emits the arrival teaser. Split out of zoneCmdGo so `!zone unlock` — which
+// reaches the same place by paying for it — cannot drift from the plain
+// `!zone go` arrival: same region-transition hook, same camp strike, same
+// boss/elite prompt. header, if set, is printed above the move.
+func (p *AdventurePlugin) commitForkChoice(
+	ctx MessageContext, run *DungeonRun, chosen pendingChoice, header string,
+) error {
 	nextIdx, aerr := advanceZoneRunNode(run.RunID, chosen.To)
 	if aerr != nil {
 		return p.SendDM(ctx.Sender, "Couldn't advance: "+aerr.Error())
@@ -200,6 +211,7 @@ func (p *AdventurePlugin) zoneCmdGo(ctx MessageContext, rest string) error {
 	fireGraphRegionTransition(run.UserID, fromNode, nextNode)
 	nextRoom := nodeKindToRoomType(nextNode.Kind)
 	var b strings.Builder
+	b.WriteString(header)
 	if kind := autoBreakCampOnMove(ctx.Sender); kind != "" {
 		b.WriteString(fmt.Sprintf("⛺ Camp struck (**%s**) — the party moved on.\n\n", kind))
 	}

internal/plugin/zone_graph_nav.go

@@ -19,6 +19,8 @@ import (
 	"strings"
 
 	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
 )
 
 // pendingFork is the typed shape of dnd_zone_run.node_choices when the
@@ -82,11 +84,39 @@ type edgeUnlockCtx struct {
 	RunID     string
 	FromNode  string
 	CharLevel int
-	AbilityMods    [6]int // STR, DEX, CON, INT, WIS, CHA — matches DnDCharacter.Modifiers()
+	// AbilityMods is the *party's best* modifier per ability — STR, DEX, CON,
+	// INT, WIS, CHA, matching DnDCharacter.Modifiers(). A door doesn't care
+	// which set of eyes spotted the seam, and reading only the leader's sheet
+	// meant a party's rogue and its hired scout were decorative at every lock.
+	// AbilityWho names whoever supplied each best, empty when it's the leader,
+	// so the fork prompt can say who got it open.
+	AbilityMods    [6]int
+	AbilityWho     [6]string
 	InventoryNames map[string]bool
 	Expedition     *Expedition
 }
 
+// creditFor names the party member whose ability carried a check, phrased for
+// the fork prompt. Empty when the acting character managed it alone — there is
+// nobody to credit and the menu stays quiet.
+func (c edgeUnlockCtx) creditFor(ability int) string {
+	if who := c.AbilityWho[ability]; who != "" {
+		return who + " got it open"
+	}
+	return ""
+}
+
+// bestAbility folds one body's modifiers into the running party-best, recording
+// the contributor's name for any ability it improves on.
+func (c *edgeUnlockCtx) bestAbility(mods [6]int, who string) {
+	for i, m := range mods {
+		if m > c.AbilityMods[i] {
+			c.AbilityMods[i] = m
+			c.AbilityWho[i] = who
+		}
+	}
+}
+
 // evaluateEdgeLock returns whether the player can take this edge right
 // now, with a player-facing reason on failure. Per plan §G5: Perception
 // rolls fire once at fork-arrival (deterministic seed) and the result
@@ -101,7 +131,7 @@ func evaluateEdgeLock(e ZoneEdge, ctx edgeUnlockCtx) (unlocked bool, reason stri
 		roll := perceptionRollForEdge(ctx.RunID, ctx.FromNode, e.To)
 		total := roll + ctx.AbilityMods[4]
 		if total >= dc {
-			return true, ""
+			return true, ctx.creditFor(4)
 		}
 		return false, fmt.Sprintf("Perception %d vs DC %d", total, dc)
 	case LockKey:
@@ -138,7 +168,7 @@ func evaluateEdgeLock(e ZoneEdge, ctx edgeUnlockCtx) (unlocked bool, reason stri
 		roll := perceptionRollForEdge(ctx.RunID, ctx.FromNode, e.To)
 		total := roll + ctx.AbilityMods[idx]
 		if total >= dc {
-			return true, ""
+			return true, ctx.creditFor(idx)
 		}
 		return false, fmt.Sprintf("%s %d vs DC %d", stat, total, dc)
 	}
@@ -219,10 +249,45 @@ func buildUnlockCtx(c *DnDCharacter, runID, fromNode string) edgeUnlockCtx {
 	}
 	if exp, err := getActiveExpedition(c.UserID); err == nil && exp != nil {
 		ctx.Expedition = exp
+		foldPartyAbilities(&ctx, exp, c.UserID)
 	}
 	return ctx
 }
 
+// foldPartyAbilities raises ctx.AbilityMods to the best any body on the
+// expedition can offer. The companion counts: he is a seat that walks the same
+// corridor, and excluding him would make hiring a scout worth less than the
+// coins it costs.
+//
+// Errors are swallowed rather than propagated — a roster read that fails leaves
+// the leader's own mods standing, which is exactly the pre-party behaviour and
+// never harder than it was.
+func foldPartyAbilities(ctx *edgeUnlockCtx, exp *Expedition, acting id.UserID) {
+	seats, err := expeditionParty(exp.ID, string(exp.UserID))
+	if err != nil {
+		return
+	}
+	for _, s := range seats {
+		if s.Kind == SeatCompanion {
+			class, level := companionLoadout(exp.ID)
+			ctx.bestAbility(companionSheet(class, level).Modifiers(), companionDisplayName)
+			continue
+		}
+		if s.UserID == acting {
+			continue // whoever we built the ctx from is already the baseline
+		}
+		mate, err := LoadDnDCharacter(s.UserID)
+		if err != nil || mate == nil {
+			continue
+		}
+		name, _ := loadDisplayName(s.UserID)
+		if name == "" {
+			name = string(s.UserID)
+		}
+		ctx.bestAbility(mate.Modifiers(), name)
+	}
+}
+
 // evaluateForkEdges walks all outgoing edges of fromNode in the graph
 // and produces a pending-choice list ready to be persisted. Locked
 // edges that have a Hint stay in the menu (the player needs the
@@ -288,6 +353,10 @@ func renderForkPrompt(zone ZoneDefinition, pf pendingFork) string {
 	b.WriteString(fmt.Sprintf("**%s — Path divides.** Choose with `!zone go <n>`.\n\n", zone.Display))
 	for _, c := range pf.Options {
 		switch {
+		case c.Unlocked && c.Reason != "":
+			// A party-mate's ability beat the check — say so, so the player can
+			// see what the roster bought them.
+			b.WriteString(fmt.Sprintf("**%d.** %s _(%s)_\n", c.Index, c.Label, c.Reason))
 		case c.Unlocked:
 			b.WriteString(fmt.Sprintf("**%d.** %s\n", c.Index, c.Label))
 		case c.Hint != "":

internal/plugin/zone_graph_unlock.go

@@ -0,0 +1,161 @@
+package plugin
+
+import (
+	"fmt"
+	"strings"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// Thieves' tools — the counterweight to a failed skill check.
+//
+// A Perception / stat-check lock rolls once per (run, edge) and the roll is
+// seeded, deliberately, so re-reading the fork can't reroll it (plan §G5). That
+// half shipped; the other half never did, so a bad roll simply deleted a branch
+// of the graph for the rest of the run with no recourse at all — worst for a
+// solo low-WIS character, who quietly loses routes they never learn existed.
+//
+// Tools are that recourse: a consumable that answers the check instead of the
+// character. They are deliberately NOT a skeleton key. A key lock is a quest
+// token, a level-min lock is progression, and a region-clear lock is structure —
+// none of those are "you rolled badly", so none of them are pickable. Tools open
+// exactly the locks that luck closed.
+
+// thievesToolsName is the inventory item name. Matching is case-folded so a
+// player typing it back at the shop doesn't have to find the apostrophe.
+const thievesToolsName = "Thieves' Tools"
+
+// thievesToolsItemType keeps them out of the combat consumable scan. They are a
+// utility item like the medical-debt card, not something the fight engine may
+// spend on the player's behalf.
+const thievesToolsItemType = "tool"
+
+// thievesToolsPrice is what Luigi charges. Priced against a T1 consumable so
+// carrying a couple is a routine purchase rather than a considered one — the
+// point is that no run is ever hard-walled, not to open a money sink.
+const thievesToolsPrice int64 = 600
+
+// pickableLock reports whether tools can answer this lock. Only the two
+// dice-driven kinds qualify; see the file comment for why the rest don't.
+func pickableLock(kind string) bool {
+	return kind == string(LockPerception) || kind == string(LockStatCheck)
+}
+
+// findThievesTools returns the inventory row ID of one set of tools, or ok=false
+// if the player is carrying none.
+func findThievesTools(userID id.UserID) (int64, bool) {
+	inv, err := loadAdvInventory(userID)
+	if err != nil {
+		return 0, false
+	}
+	for _, it := range inv {
+		if strings.EqualFold(it.Name, thievesToolsName) {
+			return it.ID, true
+		}
+	}
+	return 0, false
+}
+
+// countThievesTools reports how many sets the player carries, for the "N left"
+// line after a use.
+func countThievesTools(userID id.UserID) int {
+	inv, err := loadAdvInventory(userID)
+	if err != nil {
+		return 0
+	}
+	n := 0
+	for _, it := range inv {
+		if strings.EqualFold(it.Name, thievesToolsName) {
+			n++
+		}
+	}
+	return n
+}
+
+// zoneCmdUnlock handles `!zone unlock <n>`: spend one set of thieves' tools to
+// open a locked fork option, then commit the move exactly as `!zone go <n>`
+// would. Every guard zoneCmdGo applies applies here too — same run, same leader
+// rule, same mid-fight refusal — because this is that command with a different
+// admission price.
+func (p *AdventurePlugin) zoneCmdUnlock(ctx MessageContext, rest string) error {
+	run, isLeader, err := activeZoneRunFor(ctx.Sender)
+	if err != nil {
+		return p.SendDM(ctx.Sender, "Couldn't read run state: "+err.Error())
+	}
+	if run == nil {
+		return p.SendDM(ctx.Sender, "No active zone run. Use `!zone enter <id>`.")
+	}
+	if !isLeader {
+		return p.SendDM(ctx.Sender, msgLeaderPicksPath)
+	}
+	if cs, _ := activeCombatSessionFor(ctx.Sender); cs != nil {
+		return p.SendDM(ctx.Sender, "⚔️ Finish your fight first — `!attack` or `!flee`.")
+	}
+	pf, derr := decodePendingFork(run.NodeChoices)
+	if derr != nil {
+		return p.SendDM(ctx.Sender, "Couldn't decode pending fork: "+derr.Error())
+	}
+	if pf == nil {
+		return p.SendDM(ctx.Sender, "No fork pending. Use "+continueHint(ctx.Sender))
+	}
+
+	rest = strings.TrimSpace(rest)
+	if rest == "" {
+		zone := zoneOrFallback(run.ZoneID)
+		return p.SendDM(ctx.Sender, "**Which one?**\n\n"+renderForkPrompt(zone, *pf)+
+			fmt.Sprintf("\n\n_`!zone unlock <n>` — spends one set of %s. You carry %d._",
+				thievesToolsName, countThievesTools(ctx.Sender)))
+	}
+	choice := atoiSafe(rest)
+	if choice < 1 || choice > len(pf.Options) {
+		return p.SendDM(ctx.Sender, fmt.Sprintf("Choice must be a number from the menu (1–%d).", len(pf.Options)))
+	}
+	chosen := pf.Options[choice-1]
+
+	if chosen.Unlocked {
+		return p.SendDM(ctx.Sender, fmt.Sprintf(
+			"**%s** is already open — no need to spend tools. `!zone go %d`.", chosen.Label, choice))
+	}
+	if !pickableLock(chosen.Lock) {
+		return p.SendDM(ctx.Sender, fmt.Sprintf(
+			"🔒 Tools won't help here. %s\n\n_Thieves' tools answer a failed check, not a locked gate._",
+			lockRefusalFor(chosen)))
+	}
+	toolID, ok := findThievesTools(ctx.Sender)
+	if !ok {
+		return p.SendDM(ctx.Sender, fmt.Sprintf(
+			"🔒 **%s** needs %s and you're carrying none.\n\nLuigi stocks them under `!shop` → Supplies.",
+			chosen.Label, thievesToolsName))
+	}
+	if rerr := removeAdvInventoryItem(toolID); rerr != nil {
+		return p.SendDM(ctx.Sender, "Couldn't spend the tools: "+rerr.Error())
+	}
+
+	// The tools answered the check, so the option is open from here on. Commit
+	// it back to the pending fork before advancing: if the advance fails, the
+	// player has paid and must not be told the door is shut again.
+	pf.Options[choice-1].Unlocked = true
+	pf.Options[choice-1].Reason = "opened with " + thievesToolsName
+	_ = writePendingFork(run.RunID, *pf)
+
+	left := countThievesTools(ctx.Sender)
+	header := fmt.Sprintf("🔓 **%s** — picked. _(%s used, %d left)_\n\n", chosen.Label, thievesToolsName, left)
+	return p.commitForkChoice(ctx, run, pf.Options[choice-1], header)
+}
+
+// lockRefusalFor phrases why a non-pickable lock stays shut, preferring the
+// evaluator's own reason so the player sees the same wording the menu gave.
+func lockRefusalFor(c pendingChoice) string {
+	if c.Reason != "" {
+		return c.Reason + "."
+	}
+	switch c.Lock {
+	case string(LockKey):
+		return "That door wants a key, and a key is a thing you find, not a thing you force."
+	case string(LockLevelMin):
+		return "That way is beyond you yet. Come back stronger."
+	case string(LockRegionClear):
+		return "Somewhere else has to fall first."
+	}
+	return "That one isn't going to open."
+}

internal/plugin/zone_graph_unlock_test.go

@@ -0,0 +1,109 @@
+package plugin
+
+import "testing"
+
+// TestPickableLock pins which locks thieves' tools may answer. Tools substitute
+// for a failed die roll, never for progression: a key is a quest token, a level
+// gate is progression, a region-clear gate is structure.
+func TestPickableLock(t *testing.T) {
+	pickable := []ZoneEdgeLockKind{LockPerception, LockStatCheck}
+	for _, k := range pickable {
+		if !pickableLock(string(k)) {
+			t.Errorf("%s should be pickable", k)
+		}
+	}
+	sealed := []ZoneEdgeLockKind{LockKey, LockLevelMin, LockRegionClear, LockNone, ""}
+	for _, k := range sealed {
+		if pickableLock(string(k)) {
+			t.Errorf("%s must not be pickable", k)
+		}
+	}
+}
+
+// TestBestAbilityTakesPartyMax is the core of the party-check fix: a door reads
+// the best eyes present, not the leader's.
+func TestBestAbilityTakesPartyMax(t *testing.T) {
+	ctx := edgeUnlockCtx{AbilityMods: [6]int{0, 1, 0, 0, 1, 0}}
+	ctx.bestAbility([6]int{0, 5, 0, 0, -1, 0}, "Josie")
+	ctx.bestAbility([6]int{0, 2, 0, 0, 6, 0}, "Pete")
+
+	if ctx.AbilityMods[1] != 5 || ctx.AbilityWho[1] != "Josie" {
+		t.Errorf("DEX = %d by %q, want 5 by Josie", ctx.AbilityMods[1], ctx.AbilityWho[1])
+	}
+	if ctx.AbilityMods[4] != 6 || ctx.AbilityWho[4] != "Pete" {
+		t.Errorf("WIS = %d by %q, want 6 by Pete", ctx.AbilityMods[4], ctx.AbilityWho[4])
+	}
+	// Nobody beat the leader's STR, so nobody is credited for it.
+	if ctx.AbilityWho[0] != "" {
+		t.Errorf("STR credited to %q, want nobody", ctx.AbilityWho[0])
+	}
+}
+
+// TestEvaluateEdgeLockUsesPartyBest — a check the leader fails and a party-mate
+// passes must open, and must say who opened it.
+func TestEvaluateEdgeLockUsesPartyBest(t *testing.T) {
+	e := ZoneEdge{To: "z.secret", Lock: LockPerception, LockData: map[string]any{"dc": 30}}
+	ctx := edgeUnlockCtx{RunID: "run1", FromNode: "z.fork"}
+
+	if ok, _ := evaluateEdgeLock(e, ctx); ok {
+		t.Fatal("DC 30 should be unreachable with no modifiers")
+	}
+
+	// perceptionRollForEdge is seeded, so a mod big enough to clear DC 30 from
+	// any roll makes this deterministic without pinning the roll itself.
+	ctx.bestAbility([6]int{0, 0, 0, 0, 29, 0}, "Pete")
+	ok, reason := evaluateEdgeLock(e, ctx)
+	if !ok {
+		t.Fatalf("party best should open the door, got %q", reason)
+	}
+	if reason != "Pete got it open" {
+		t.Errorf("reason = %q, want credit to Pete", reason)
+	}
+}
+
+// TestRankForkOptionsPrefersUnvisitedThenWeight guards the autopilot's route
+// choice. Menu order is edge-authoring order and means nothing to a player.
+func TestRankForkOptionsPrefersUnvisitedThenWeight(t *testing.T) {
+	g := ZoneGraph{
+		Nodes: map[string]ZoneNode{},
+		Edges: map[string][]ZoneEdge{
+			"z.fork": {
+				{From: "z.fork", To: "z.seen", Weight: 9},
+				{From: "z.fork", To: "z.thin", Weight: 1},
+				{From: "z.fork", To: "z.fat", Weight: 5},
+			},
+		},
+	}
+	run := &DungeonRun{CurrentNode: "z.fork", VisitedNodes: []string{"z.fork", "z.seen"}}
+	pf := &pendingFork{Options: []pendingChoice{
+		{Index: 1, To: "z.seen", Label: "Seen", Unlocked: true},
+		{Index: 2, To: "z.thin", Label: "Thin", Unlocked: true},
+		{Index: 3, To: "z.fat", Label: "Fat", Unlocked: true},
+		{Index: 4, To: "z.shut", Label: "Shut", Unlocked: false},
+	}}
+
+	got := rankForkOptions(g, run, pf)
+	want := []string{"z.fat", "z.thin", "z.seen"}
+	if len(got) != len(want) {
+		t.Fatalf("got %d options, want %d (locked routes must be dropped)", len(got), len(want))
+	}
+	for i, w := range want {
+		if got[i].To != w {
+			t.Errorf("rank[%d] = %s, want %s", i, got[i].To, w)
+		}
+	}
+}
+
+// TestRankForkOptionsAllLocked — nothing takeable means nothing returned, which
+// is what sends the autopilot to the tools/backtrack path instead of the reaper.
+func TestRankForkOptionsAllLocked(t *testing.T) {
+	g := ZoneGraph{Nodes: map[string]ZoneNode{}, Edges: map[string][]ZoneEdge{}}
+	run := &DungeonRun{CurrentNode: "z.fork", VisitedNodes: []string{"z.fork"}}
+	pf := &pendingFork{Options: []pendingChoice{
+		{Index: 1, To: "z.a", Unlocked: false},
+		{Index: 2, To: "z.b", Unlocked: false},
+	}}
+	if got := rankForkOptions(g, run, pf); len(got) != 0 {
+		t.Errorf("got %d takeable options, want 0", len(got))
+	}
+}