fix(ui): restore authentic D2 v1.13c NPC dialog popup menu (Fixes #489)

Merge pull request 'fix(ui): align Private Stash header and gold text inside TradeStash.dc6 recessed boxes (#493)' (#494) from fix/stash-text-align into main

src/game/drop-pipeline.ts

@@ -566,6 +566,21 @@ export function rollItemEtherealAndSockets(
   return { ethereal, sockets }
 }
 
+/**
+ * Per 1.13c D2Game.dll (ITEMS_Create / 0x6FC2FC40):
+ * - Low Quality (1), Normal (2), Superior (3), and Quest items (quest > 0) spawn identified.
+ * - Magic (4), Set (5), Rare (6), Unique (7), and Crafted (8) non-quest items spawn unidentified on drop.
+ */
+export function shouldSpawnIdentifiedByDefault(
+  base: ItemBase,
+  qualityTier: ItemQualityTier,
+): boolean {
+  if ((base.quest ?? 0) > 0) {
+    return true
+  }
+  return qualityTier === 'low' || qualityTier === 'normal' || qualityTier === 'superior'
+}
+
 /**
  * Creates a concrete Item instance for a dropped leaf item.
  */
@@ -587,10 +602,12 @@ export function createDroppedItem(
     readonly dwInitSeed: number
     readonly durabilityMultiplier?: number | undefined
     readonly itemRng?: D2Rng | undefined
+    readonly identified?: boolean | undefined
   },
 ): Item {
   const quality = QUALITY_TIER_TO_ITEM_QUALITY[qualityTier] ?? ItemQuality.NORMAL
-  let rawFlags = ItemFlag.IDENTIFIED
+  const isIdentified = options.identified ?? shouldSpawnIdentifiedByDefault(base, qualityTier)
+  let rawFlags = isIdentified ? ItemFlag.IDENTIFIED : 0
 
   let name = base.name
   let prefix = null
@@ -894,6 +911,7 @@ export function createDroppedItem(
     value: base.value,
     rawFlags,
     flags: decodeItemFlags(rawFlags),
+    identified: isIdentified,
     version: 0x65,
     code: formatItemCode(base.id),
     quality,

src/game/engine.ts

@@ -1452,12 +1452,19 @@ export class GameEngine {
     const currentSimTime = this.world.tick * 40
     const spawned: GroundItemEntity[] = []
 
+    const reachableFrom = { x: this.world.player.x, y: this.world.player.y }
+
     for (const drop of droppedItems) {
       const dropPos = findIsometricDropPosition(
         pending.x,
         pending.y,
         burstOccupied,
         this.terrain,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        reachableFrom,
       )
       burstOccupied.push(dropPos)
       const dropCell = worldToCell(this.terrain, dropPos.x, dropPos.y)
@@ -1486,11 +1493,17 @@ export class GameEngine {
   dropItem(item: GroundItemSource, x?: number, y?: number, cellX?: number, cellY?: number): GroundItemEntity {
     const rawX = x ?? this.world.player.x
     const rawY = y ?? this.world.player.y
+    const reachableFrom = { x: this.world.player.x, y: this.world.player.y }
     const dropPos = findIsometricDropPosition(
       rawX,
       rawY,
       this.groundItems.all,
       this.terrain,
+      undefined,
+      undefined,
+      undefined,
+      undefined,
+      reachableFrom,
     )
     const finalX = dropPos.x
     const finalY = dropPos.y
@@ -1518,11 +1531,17 @@ export class GameEngine {
     if (amount <= 0) return null
     const rawX = x ?? this.world.player.x
     const rawY = y ?? this.world.player.y
+    const reachableFrom = { x: this.world.player.x, y: this.world.player.y }
     const dropPos = findIsometricDropPosition(
       rawX,
       rawY,
       this.groundItems.all,
       this.terrain,
+      undefined,
+      undefined,
+      undefined,
+      undefined,
+      reachableFrom,
     )
     const finalX = dropPos.x
     const finalY = dropPos.y

src/game/ground-items.ts

@@ -15,7 +15,10 @@ import type { Item } from './items.ts'
 import {
   COLLIDE_WALL,
   COLLIDE_BLANK,
+  COLLIDE_WATER,
+  COLLIDE_NO_PATH,
   COLLIDE_MASK_INVALID,
+  COLLIDE_MASK_PLAYER_PATH,
   COLLIDE_NONE,
   COLLIDE_ITEM,
   COLLIDE_MASK_SPAWN,
@@ -24,15 +27,37 @@ import {
   ORTHO_CELL_HEIGHT,
   ORTHO_SUB_TILE_WIDTH,
   ORTHO_SUB_TILE_HEIGHT,
+  getCollisionMask,
   getCollisionMaskAt,
   isBlockedAt,
   rayTraceScene,
+  subTileAt,
 } from './d2map.ts'
 import type { CollisionGrid } from './d2map.ts'
-import { translateItemName, translateMagicName, translateRareName } from './tooltip-i18n.ts'
+import {
+  resolveBaseItemNameEn,
+  translateItemName,
+  translateMagicName,
+  translateRareName,
+} from './tooltip-i18n.ts'
 import { isRuneCode } from './gems-data.ts'
 import { getEmbeddedDropTables } from './embedded-drop-tables.ts'
 
+/**
+ * Composite collision mask for ground item & gold drops.
+ * Combines D2Common.dll `COLLISION_GetFreeCoordinatesImpl` (`COLLIDE_MASK_SPAWN = 0x3E01`)
+ * with player walkability masks (`COLLIDE_MASK_PLAYER_PATH`, `COLLIDE_BLANK`, `COLLIDE_WATER`,
+ * `COLLIDE_MASK_INVALID`, `COLLIDE_NO_PATH`) so items never land on tiles a player cannot walk onto.
+ */
+export const COLLIDE_MASK_DROP_BLOCK =
+  COLLIDE_MASK_SPAWN |
+  COLLIDE_MASK_PLAYER_PATH |
+  COLLIDE_BLANK |
+  COLLIDE_WATER |
+  COLLIDE_MASK_INVALID |
+  COLLIDE_NO_PATH
+
+
 export interface GroundItemBounceState {
   startTime: number
   durationMs: number
@@ -181,6 +206,25 @@ export interface GroundItemMetadata {
   readonly sockets?: number | undefined
 }
 
+/**
+ * Checks whether an item or GroundItemSource is currently unidentified.
+ */
+export function isGroundSourceUnidentified(item: any): boolean {
+  if (!item || isGoldItem(item)) return false
+  if (item.identified === false) return true
+  if (item.identified === true) return false
+  if (item.flags && typeof item.flags.identified === 'boolean') {
+    return item.flags.identified === false
+  }
+  if (item.rawItem && item.rawItem !== item) {
+    return isGroundSourceUnidentified(item.rawItem)
+  }
+  if (item.item && item.item !== item) {
+    return isGroundSourceUnidentified(item.item)
+  }
+  return false
+}
+
 /** Extract ground item metadata from any item source. */
 export function resolveGroundItemMetadata(item: any, specifiedAmount?: number): GroundItemMetadata {
   const isGold = isGoldItem(item)
@@ -208,21 +252,15 @@ export function resolveGroundItemMetadata(item: any, specifiedAmount?: number):
     }
   }
 
-  const name = typeof item?.name === 'string' ? item.name : 'Unknown Item'
   const rawCode = typeof item?.code === 'string'
     ? item.code.trim().toLowerCase()
     : typeof item?.base?.id === 'string'
       ? item.base.id.trim().toLowerCase()
-      : ''
-  const quality = resolveItemQualityString(item?.quality ?? item?.base?.quality, rawCode, item)
-  const nameZh = formatBilingualGroundItemName(item, name, quality)
-  if (item && typeof item === 'object' && (!item.nameZh || item.nameZh === name) && nameZh) {
-    try {
-      item.nameZh = nameZh
-    } catch {
-      // ignore if frozen object
-    }
-  }
+      : typeof item?.rawItem?.code === 'string'
+        ? item.rawItem.code.trim().toLowerCase()
+        : typeof item?.rawItem?.base?.id === 'string'
+          ? item.rawItem.base.id.trim().toLowerCase()
+          : ''
 
   let tableBase: any
   if (rawCode && (!item?.base || (item?.base?.dropsound === undefined && item?.dropSound === undefined && item?.dropsound === undefined))) {
@@ -236,6 +274,39 @@ export function resolveGroundItemMetadata(item: any, specifiedAmount?: number):
     }
   }
 
+  const rawName = typeof item?.name === 'string' ? item.name : 'Unknown Item'
+  const quality = resolveItemQualityString(item?.quality ?? item?.base?.quality, rawCode, item)
+  const unidentified = isGroundSourceUnidentified(item)
+
+  let name = rawName
+  let nameZh: string
+  if (unidentified) {
+    const baseObj = item?.base ?? item?.rawItem?.base ?? tableBase
+    const rawBaseName =
+      typeof baseObj?.name === 'string' && baseObj.name.trim().length > 0
+        ? baseObj.name
+        : rawName
+    const baseNameEn = resolveBaseItemNameEn(rawBaseName, rawCode)
+    const translatedBase =
+      translateItemName(rawBaseName) !== rawBaseName
+        ? translateItemName(rawBaseName)
+        : translateItemName(baseNameEn)
+    name = baseNameEn
+    nameZh =
+      translatedBase && translatedBase !== baseNameEn
+        ? `${translatedBase} (${baseNameEn})`
+        : baseNameEn
+  } else {
+    nameZh = formatBilingualGroundItemName(item, name, quality)
+    if (item && typeof item === 'object' && (!item.nameZh || item.nameZh === name) && nameZh) {
+      try {
+        item.nameZh = nameZh
+      } catch {
+        // ignore if frozen object
+      }
+    }
+  }
+
   const invWidth = typeof item?.invWidth === 'number' ? item.invWidth : (item?.base?.invWidth ?? tableBase?.invWidth ?? 1)
   const invHeight = typeof item?.invHeight === 'number' ? item.invHeight : (item?.base?.invHeight ?? tableBase?.invHeight ?? 1)
   const amount = typeof item?.stack === 'number' ? item.stack : 1
@@ -332,7 +403,7 @@ export function triggerFlippyBounce(
 /**
  * Concentric quadrant spiral neighbor search around origin (D2Common.dll ITEM_Drop / COLLISION_GetFreeCoordinatesImpl parity).
  * Searches radius 0, 1, 2, ... up to maxRadius in authentic 1.13c quadrant order for the first walkable cell
- * not blocked by COLLIDE_WALL, COLLIDE_BLANK, or COLLIDE_MASK_INVALID, and not occupied by existing items.
+ * not blocked by COLLIDE_MASK_DROP_BLOCK or player overlap, 4-connected to the drop/player room, and not occupied by existing items.
  */
 export function findSafeDropPosition(
   grid: any,
@@ -340,22 +411,23 @@ export function findSafeDropPosition(
   originCellY: number,
   maxRadius = 3,
   occupied?: readonly { cellX?: number; cellY?: number; x?: number; y?: number }[] | Set<string> | ((cx: number, cy: number) => boolean),
+  reachableFromCell?: { cellX: number; cellY: number },
 ): { cellX: number; cellY: number; x: number; y: number } {
   const targetGrid = grid?.grid ?? grid
 
   const isBlocked = (cx: number, cy: number): boolean => {
-    if (!targetGrid) return false
+    if (!targetGrid && typeof grid?.overlap !== 'function') return false
 
     // 1. Function check (e.g. overlap callback or mock in tests)
     if (typeof targetGrid === 'function') {
       return targetGrid(cx, cy) !== 0
     }
-    if (typeof targetGrid.isBlocked === 'function') {
+    if (typeof targetGrid?.isBlocked === 'function') {
       return targetGrid.isBlocked(cx, cy)
     }
 
     // 2. Real CollisionGrid (cellsX, cellsY, gridWidth, blocked, optional collisionMasks)
-    if (typeof targetGrid.cellsX === 'number' && typeof targetGrid.cellsY === 'number') {
+    if (typeof targetGrid?.cellsX === 'number' && typeof targetGrid?.cellsY === 'number') {
       if (cx < 0 || cy < 0 || cx >= targetGrid.cellsX || cy >= targetGrid.cellsY) {
         return true // Out of map bounds -> COLLIDE_MASK_INVALID
       }
@@ -367,18 +439,35 @@ export function findSafeDropPosition(
 
       if (targetGrid.collisionMasks) {
         const mask = targetGrid.collisionMasks[subIdx] ?? COLLIDE_NONE
-        if ((mask & (COLLIDE_WALL | COLLIDE_BLANK | COLLIDE_MASK_INVALID)) !== 0) {
+        if ((mask & COLLIDE_MASK_DROP_BLOCK) !== 0) {
           return true
         }
       }
       if (targetGrid.blocked && targetGrid.blocked[subIdx] === 1) {
         return true
       }
+      if (typeof grid?.overlap === 'function' && grid.widthPx !== undefined && grid.heightPx !== undefined) {
+        const oX = typeof grid.originX === 'number'
+          ? grid.originX
+          : typeof targetGrid.originX === 'number'
+            ? targetGrid.originX
+            : 0
+        const oY = typeof grid.originY === 'number'
+          ? grid.originY
+          : typeof targetGrid.originY === 'number'
+            ? targetGrid.originY
+            : 0
+        const wx = oX + (cx - cy) * ORTHO_CELL_WIDTH
+        const wy = oY + (cx + cy) * ORTHO_CELL_HEIGHT
+        if (grid.overlap(wx, wy) > 0) {
+          return true
+        }
+      }
       return false
     }
 
     // 3. TypedArray directly (e.g. new Uint8Array(400) or new Uint16Array(width * height))
-    if (ArrayBuffer.isView(targetGrid)) {
+    if (targetGrid && ArrayBuffer.isView(targetGrid)) {
       if (cx < 0 || cy < 0) return true
       const width = typeof (targetGrid as any).width === 'number'
         ? (targetGrid as any).width
@@ -394,11 +483,11 @@ export function findSafeDropPosition(
       if (height > 0 && cy >= height) return true
       const idx = cy * width + cx
       const val = (targetGrid as any)[idx] ?? COLLIDE_NONE
-      return (val & (COLLIDE_WALL | COLLIDE_BLANK | COLLIDE_MASK_INVALID)) !== 0 || val === 1
+      return (val & COLLIDE_MASK_DROP_BLOCK) !== 0 || val === 1
     }
 
     // 4. Test grid object with cells or collisionMasks array
-    if (targetGrid.cells || targetGrid.collisionMasks) {
+    if (targetGrid?.cells || targetGrid?.collisionMasks) {
       if (cx < 0 || cy < 0) return true
       const width = targetGrid.width ?? targetGrid.cellsX ?? 0
       const height = targetGrid.height ?? targetGrid.cellsY ?? 0
@@ -407,19 +496,20 @@ export function findSafeDropPosition(
 
       const idx = cy * width + cx
       const mask = (targetGrid.collisionMasks ? targetGrid.collisionMasks[idx] : targetGrid.cells[idx]) ?? COLLIDE_NONE
-      return (mask & (COLLIDE_WALL | COLLIDE_BLANK | COLLIDE_MASK_INVALID)) !== 0
+      return (mask & COLLIDE_MASK_DROP_BLOCK) !== 0
     }
 
     // 5. CountingTerrain / WorldMapProvider overlap callback
-    if (typeof targetGrid.overlap === 'function') {
-      if (targetGrid.widthPx !== undefined && targetGrid.heightPx !== undefined) {
-        const originX = typeof targetGrid.originX === 'number' ? targetGrid.originX : 0
-        const originY = typeof targetGrid.originY === 'number' ? targetGrid.originY : 0
+    const overlapTarget = typeof grid?.overlap === 'function' ? grid : targetGrid
+    if (typeof overlapTarget?.overlap === 'function') {
+      if (overlapTarget.widthPx !== undefined && overlapTarget.heightPx !== undefined) {
+        const originX = typeof overlapTarget.originX === 'number' ? overlapTarget.originX : 0
+        const originY = typeof overlapTarget.originY === 'number' ? overlapTarget.originY : 0
         const wx = originX + (cx - cy) * ORTHO_CELL_WIDTH
         const wy = originY + (cx + cy) * ORTHO_CELL_HEIGHT
-        return targetGrid.overlap(wx, wy) > 0
+        return overlapTarget.overlap(wx, wy) > 0
       }
-      return targetGrid.overlap(cx, cy) !== 0
+      return overlapTarget.overlap(cx, cy) !== 0
     }
 
     return false
@@ -453,19 +543,137 @@ export function findSafeDropPosition(
     return occupiedSet.has(`${cx},${cy}`)
   }
 
-  let chosenCellX = originCellX
-  let chosenCellY = originCellY
+  // Optional 4-connected reachability from reachableFromCell
+  let baseCellX = originCellX
+  let baseCellY = originCellY
+  let playerReachableCells: Set<string> | null = null
+
+  if (
+    reachableFromCell &&
+    Number.isFinite(reachableFromCell.cellX) &&
+    Number.isFinite(reachableFromCell.cellY) &&
+    !isBlocked(reachableFromCell.cellX, reachableFromCell.cellY)
+  ) {
+    const startX = reachableFromCell.cellX
+    const startY = reachableFromCell.cellY
+    const margin = Math.max(maxRadius + 4, 12)
+    const minX = Math.min(startX, originCellX) - margin
+    const maxX = Math.max(startX, originCellX) + margin
+    const minY = Math.min(startY, originCellY) - margin
+    const maxY = Math.max(startY, originCellY) + margin
+
+    playerReachableCells = new Set<string>([`${startX},${startY}`])
+    const queue: [number, number][] = [[startX, startY]]
+    let head = 0
+    while (head < queue.length && queue.length < 4096) {
+      const [cx, cy] = queue[head++]!
+      const neighbors: [number, number][] = [
+        [cx - 1, cy],
+        [cx + 1, cy],
+        [cx, cy - 1],
+        [cx, cy + 1],
+      ]
+      for (const [nx, ny] of neighbors) {
+        if (nx < minX || nx > maxX || ny < minY || ny > maxY) continue
+        const key = `${nx},${ny}`
+        if (playerReachableCells.has(key)) continue
+        if (isBlocked(nx, ny)) continue
+        playerReachableCells.add(key)
+        queue.push([nx, ny])
+      }
+    }
+
+    if (!playerReachableCells.has(`${originCellX},${originCellY}`)) {
+      // Snap baseCell to the reachable cell closest to originCell
+      let bestX = startX
+      let bestY = startY
+      let bestL1 = Math.abs(startX - originCellX) + Math.abs(startY - originCellY)
+      let bestDistSq = (startX - originCellX) ** 2 + (startY - originCellY) ** 2
+      for (const [rx, ry] of queue) {
+        const l1 = Math.abs(rx - originCellX) + Math.abs(ry - originCellY)
+        const dSq = (rx - originCellX) ** 2 + (ry - originCellY) ** 2
+        if (l1 < bestL1 || (l1 === bestL1 && dSq < bestDistSq)) {
+          bestL1 = l1
+          bestDistSq = dSq
+          bestX = rx
+          bestY = ry
+        }
+      }
+      baseCellX = bestX
+      baseCellY = bestY
+    }
+  }
+
+  const baseWalkable = !isBlocked(baseCellX, baseCellY)
+  let anchorConnectedCells: Set<string> | null = null
+  const isConnectedToBase = (cx: number, cy: number): boolean => {
+    if (playerReachableCells !== null) {
+      return playerReachableCells.has(`${cx},${cy}`)
+    }
+    if (!baseWalkable) return true
+    if (cx === baseCellX && cy === baseCellY) return true
+
+    // Fast greedy 4-way walk check from (baseCellX, baseCellY) to (cx, cy)
+    let curX = baseCellX
+    let curY = baseCellY
+    let greedyOk = true
+    while (curX !== cx || curY !== cy) {
+      const remX = Math.abs(cx - curX)
+      const remY = Math.abs(cy - curY)
+      const stepX = curX < cx ? 1 : -1
+      const stepY = curY < cy ? 1 : -1
+      if (remX >= remY && remX > 0 && !isBlocked(curX + stepX, curY)) {
+        curX += stepX
+      } else if (remY > 0 && !isBlocked(curX, curY + stepY)) {
+        curY += stepY
+      } else if (remX > 0 && !isBlocked(curX + stepX, curY)) {
+        curX += stepX
+      } else {
+        greedyOk = false
+        break
+      }
+    }
+    if (greedyOk) return true
+
+    if (anchorConnectedCells === null) {
+      const bound = Math.max(maxRadius + 2, 6)
+      anchorConnectedCells = new Set<string>([`${baseCellX},${baseCellY}`])
+      const q: [number, number][] = [[baseCellX, baseCellY]]
+      let h = 0
+      while (h < q.length && q.length < 1024) {
+        const [qx, qy] = q[h++]!
+        const nbs: [number, number][] = [
+          [qx - 1, qy],
+          [qx + 1, qy],
+          [qx, qy - 1],
+          [qx, qy + 1],
+        ]
+        for (const [nx, ny] of nbs) {
+          if (Math.abs(nx - baseCellX) > bound || Math.abs(ny - baseCellY) > bound) continue
+          const k = `${nx},${ny}`
+          if (anchorConnectedCells.has(k)) continue
+          if (isBlocked(nx, ny)) continue
+          anchorConnectedCells.add(k)
+          q.push([nx, ny])
+        }
+      }
+    }
+    return anchorConnectedCells.has(`${cx},${cy}`)
+  }
+
+  let chosenCellX = baseCellX
+  let chosenCellY = baseCellY
   let found = false
   let firstWalkableOccupied: { cx: number; cy: number } | null = null
 
-  // Ring 0: check origin cell
-  if (!isBlocked(originCellX, originCellY)) {
-    if (!isCellOccupied(originCellX, originCellY)) {
-      chosenCellX = originCellX
-      chosenCellY = originCellY
+  // Ring 0: check base cell
+  if (baseWalkable && isConnectedToBase(baseCellX, baseCellY)) {
+    if (!isCellOccupied(baseCellX, baseCellY)) {
+      chosenCellX = baseCellX
+      chosenCellY = baseCellY
       found = true
     } else {
-      firstWalkableOccupied = { cx: originCellX, cy: originCellY }
+      firstWalkableOccupied = { cx: baseCellX, cy: baseCellY }
     }
   }
 
@@ -474,10 +682,10 @@ export function findSafeDropPosition(
     for (let r = 1; r <= maxRadius; r += 1) {
       const ringCandidates = getIsometricRingCandidates(r)
       for (const cand of ringCandidates) {
-        const cx = originCellX + cand.dx
-        const cy = originCellY + cand.dy
+        const cx = baseCellX + cand.dx
+        const cy = baseCellY + cand.dy
 
-        if (isBlocked(cx, cy)) {
+        if (isBlocked(cx, cy) || !isConnectedToBase(cx, cy)) {
           continue
         }
 
@@ -497,6 +705,32 @@ export function findSafeDropPosition(
     }
   }
 
+  // Extended escape search when origin itself is blocked and maxRadius > 0
+  if (!found && firstWalkableOccupied === null && !baseWalkable && maxRadius > 0) {
+    const extendedMax = Math.max(maxRadius, 15)
+    for (let r = maxRadius + 1; r <= extendedMax; r += 1) {
+      const ringCandidates = getIsometricRingCandidates(r)
+      for (const cand of ringCandidates) {
+        const cx = baseCellX + cand.dx
+        const cy = baseCellY + cand.dy
+        if (isBlocked(cx, cy) || !isConnectedToBase(cx, cy)) {
+          continue
+        }
+        if (isCellOccupied(cx, cy)) {
+          if (firstWalkableOccupied === null) {
+            firstWalkableOccupied = { cx, cy }
+          }
+          continue
+        }
+        chosenCellX = cx
+        chosenCellY = cy
+        found = true
+        break
+      }
+      if (found) break
+    }
+  }
+
   // Authentic Fallback:
   // If all candidate cells within maxRadius are occupied, stack on first walkable floor cell
   // rather than escaping into void or walls.
@@ -529,8 +763,142 @@ export function findSafeDropPosition(
   }
 }
 
+/** Extract a CollisionGrid from either a direct CollisionGrid or a CountingTerrain wrapper. */
+function extractCollisionGrid(isBlocked: any): CollisionGrid | undefined {
+  if (!isBlocked || typeof isBlocked !== 'object') return undefined
+  if (isBlocked.collisionMasks !== undefined || isBlocked.gridWidth !== undefined) {
+    return isBlocked as CollisionGrid
+  }
+  if (isBlocked.grid && (isBlocked.grid.collisionMasks !== undefined || isBlocked.grid.gridWidth !== undefined)) {
+    return isBlocked.grid as CollisionGrid
+  }
+  return undefined
+}
+
 /**
- * Helper to check whether a candidate world position is blocked by collision or Line-of-Sight.
+ * Checks whether a single world coordinate `(x, y)` is blocked by terrain collision masks,
+ * solid sub-tiles, or the player's physical bounding box (`overlap`).
+ */
+export function isTerrainPointBlocked(
+  x: number,
+  y: number,
+  isBlocked?: ((x: number, y: number) => boolean) | CollisionGrid | any,
+): boolean {
+  if (!isBlocked) return false
+
+  const grid = extractCollisionGrid(isBlocked)
+  if (grid !== undefined) {
+    const mask = getCollisionMaskAt(grid, x, y)
+    if ((mask & COLLIDE_MASK_DROP_BLOCK) !== 0) {
+      return true
+    }
+    if (grid.blocked && isBlockedAt(grid, x, y)) {
+      return true
+    }
+  }
+
+  if (typeof isBlocked.overlap === 'function') {
+    if (isBlocked.overlap(x, y) !== 0) {
+      return true
+    }
+  }
+
+  if (typeof isBlocked === 'function') {
+    if (isBlocked(x, y)) {
+      return true
+    }
+  }
+
+  if (typeof isBlocked.isBlocked === 'function') {
+    if (isBlocked.isBlocked(x, y)) {
+      return true
+    }
+  }
+
+  return false
+}
+
+/**
+ * Checks whether a sub-tile ray from `(fromX, fromY)` to `(toX, toY)` is blocked by
+ * `COLLIDE_MASK_SPAWN_LOS`, solid `blocked` sub-tiles, or diagonal wall-corner clipping
+ * where two orthogonal wall sub-tiles meet at a diagonal corner.
+ */
+function isSubTileRayBlocked(
+  grid: CollisionGrid,
+  fromX: number,
+  fromY: number,
+  toX: number,
+  toY: number,
+): boolean {
+  const los = rayTraceScene(grid, fromX, fromY, toX, toY, COLLIDE_MASK_SPAWN_LOS)
+  if (los.hit) {
+    return true
+  }
+
+  const start = subTileAt(grid, fromX, fromY)
+  const end = subTileAt(grid, toX, toY)
+  const gridHeight = grid.cellsY * 5
+
+  const isSubTileSolid = (subX: number, subY: number): boolean => {
+    if (subX < 0 || subY < 0 || subX >= grid.gridWidth || subY >= gridHeight) {
+      return true
+    }
+    const mask = getCollisionMask(grid, subX, subY)
+    if ((mask & (COLLIDE_MASK_SPAWN_LOS | COLLIDE_MASK_DROP_BLOCK)) !== 0) {
+      return true
+    }
+    if (grid.blocked && grid.blocked[subY * grid.gridWidth + subX] === 1) {
+      return true
+    }
+    return false
+  }
+
+  let x0 = start.subX
+  let y0 = start.subY
+  const x1 = end.subX
+  const y1 = end.subY
+  const dx = Math.abs(x1 - x0)
+  const dy = Math.abs(y1 - y0)
+  const sx = x0 < x1 ? 1 : -1
+  const sy = y0 < y1 ? 1 : -1
+  let err = dx - dy
+  let steps = 0
+
+  while (true) {
+    if (steps > 0 && isSubTileSolid(x0, y0)) {
+      return true
+    }
+    if (x0 === x1 && y0 === y1) {
+      break
+    }
+    const e2 = 2 * err
+    const stepX = e2 > -dy
+    const stepY = e2 < dx
+
+    if (stepX && stepY) {
+      // Diagonal step across sub-tile corner: block if both shared cardinal neighbors are solid
+      if (isSubTileSolid(x0 + sx, y0) && isSubTileSolid(x0, y0 + sy)) {
+        return true
+      }
+    }
+
+    if (stepX) {
+      err -= dy
+      x0 += sx
+    }
+    if (stepY) {
+      err += dx
+      y0 += sy
+    }
+    steps += 1
+  }
+
+  return false
+}
+
+/**
+ * Helper to check whether a candidate world position is blocked by collision, Line-of-Sight,
+ * or diagonal wall-corner pinching.
  */
 export function isDropPositionBlocked(
   candX: number,
@@ -541,52 +909,38 @@ export function isDropPositionBlocked(
 ): boolean {
   if (!isBlocked) return false
 
-  // 1. If it's a CollisionGrid or has a collision grid
-  const grid: CollisionGrid | undefined =
-    isBlocked.collisionMasks !== undefined || isBlocked.gridWidth !== undefined
-      ? isBlocked
-      : isBlocked.grid?.collisionMasks !== undefined || isBlocked.grid?.gridWidth !== undefined
-        ? isBlocked.grid
-        : undefined
+  if (isTerrainPointBlocked(candX, candY, isBlocked)) {
+    return true
+  }
 
+  if (candX === originX && candY === originY) {
+    return false
+  }
+
+  const grid = extractCollisionGrid(isBlocked)
   if (grid !== undefined) {
-    const mask = getCollisionMaskAt(grid, candX, candY)
-    if ((mask & COLLIDE_MASK_SPAWN) !== 0) {
-      return true
-    }
-    if (grid.blocked && isBlockedAt(grid, candX, candY)) {
-      return true
-    }
-    const los = rayTraceScene(grid, originX, originY, candX, candY, COLLIDE_MASK_SPAWN_LOS)
-    if (los.hit) {
+    if (isSubTileRayBlocked(grid, originX, originY, candX, candY)) {
       return true
     }
   }
 
-  // 2. CountingTerrain overlap check
-  if (typeof isBlocked.overlap === 'function') {
-    if (isBlocked.overlap(candX, candY) !== 0) {
-      return true
-    }
-  }
-
-  // 3. CountingTerrain LoS check
   if (typeof isBlocked.hasLineOfSight === 'function') {
     if (!isBlocked.hasLineOfSight(originX, originY, candX, candY)) {
       return true
     }
   }
 
-  // 4. Function callback (e.g. (x, y) => boolean)
-  if (typeof isBlocked === 'function') {
-    if (isBlocked(candX, candY)) {
-      return true
-    }
-  }
-
-  // 5. General isBlocked method
-  if (typeof isBlocked.isBlocked === 'function') {
-    if (isBlocked.isBlocked(candX, candY)) {
+  // Prevent diagonal corner-clipping on non-grid callbacks for 1-step diagonal sub-tile offsets
+  const relX = candX - originX
+  const relY = candY - originY
+  const dx = Math.round((relX / ORTHO_SUB_TILE_WIDTH + relY / ORTHO_SUB_TILE_HEIGHT) / 2)
+  const dy = Math.round((relY / ORTHO_SUB_TILE_HEIGHT - relX / ORTHO_SUB_TILE_WIDTH) / 2)
+  if (Math.abs(dx) === 1 && Math.abs(dy) === 1) {
+    const c1x = originX + dx * ORTHO_SUB_TILE_WIDTH
+    const c1y = originY + dx * ORTHO_SUB_TILE_HEIGHT
+    const c2x = originX - dy * ORTHO_SUB_TILE_WIDTH
+    const c2y = originY + dy * ORTHO_SUB_TILE_HEIGHT
+    if (isTerrainPointBlocked(c1x, c1y, isBlocked) && isTerrainPointBlocked(c2x, c2y, isBlocked)) {
       return true
     }
   }
@@ -635,13 +989,15 @@ export function getIsometricRingCandidates(R: number): { dx: number; dy: number;
 }
 
 /**
- * Find an unoccupied isometric grid slot around an origin coordinate.
+ * Find an unoccupied, player-reachable isometric grid slot around an origin coordinate.
  *
  * Implements Blizzard Diablo II v1.13c 2:1 isometric diamond grid scatter algorithm:
  * - Sub-tile steps: stepX = 16px, stepY = 8px (2:1 aspect ratio).
  * - Concentric square rings R = 0, 1, 2, ... up to maxRings.
  * - L1 Manhattan distance minimization (|dx| + |dy|).
- * - Collision checks against COLLIDE_MASK_SPAWN (0x3E01) and LoS raycast against COLLIDE_MASK_SPAWN_LOS (0x0801).
+ * - Collision checks against COLLIDE_MASK_DROP_BLOCK, player footprint overlap, and LoS raycast.
+ * - Verifies 4-connected walkable path reachability from the drop anchor (and from `reachableFrom`
+ *   when provided), snapping blocked or isolated drop origins to the nearest reachable floor sub-tile.
  * - Prevents item stacking by enforcing minimum spacing (default 16px).
  *
  * @param originX - epicenter X in world coordinates.
@@ -652,6 +1008,7 @@ export function getIsometricRingCandidates(R: number): { dx: number; dy: number;
  * @param stepY - isometric vertical lattice step (default ORTHO_SUB_TILE_HEIGHT = 8).
  * @param maxRings - max search rings (default 10).
  * @param minSpacing - minimum distance in pixels between ground items (default 16).
+ * @param reachableFrom - optional player world coordinates to guarantee the drop is path-reachable by the player.
  */
 export function findIsometricDropPosition(
   originX: number,
@@ -662,25 +1019,300 @@ export function findIsometricDropPosition(
   stepY = ORTHO_SUB_TILE_HEIGHT,
   maxRings = 10,
   minSpacing = 16,
+  reachableFrom?: { x: number; y: number },
 ): { x: number; y: number } {
   const minSpacingSq = minSpacing * minSpacing
+  const grid = extractCollisionGrid(isBlocked)
+
+  const coordAt = (baseX: number, baseY: number, dx: number, dy: number): { x: number; y: number } => ({
+    x: baseX + (dx - dy) * stepX,
+    y: baseY + (dx + dy) * stepY,
+  })
+
+  const isPointWalkable = (x: number, y: number): boolean => !isTerrainPointBlocked(x, y, isBlocked)
+
+  const canStepCardinal = (fromX: number, fromY: number, toX: number, toY: number): boolean => {
+    if (!isPointWalkable(toX, toY)) return false
+    if (grid !== undefined && isSubTileRayBlocked(grid, fromX, fromY, toX, toY)) return false
+    if (typeof isBlocked?.hasLineOfSight === 'function' && !isBlocked.hasLineOfSight(fromX, fromY, toX, toY)) {
+      return false
+    }
+    return true
+  }
+
+  const canGreedyWalkOnLattice = (
+    baseX: number,
+    baseY: number,
+    fromDx: number,
+    fromDy: number,
+    toDx: number,
+    toDy: number,
+  ): boolean => {
+    let curDx = fromDx
+    let curDy = fromDy
+    while (curDx !== toDx || curDy !== toDy) {
+      const curPos = coordAt(baseX, baseY, curDx, curDy)
+      const remX = Math.abs(toDx - curDx)
+      const remY = Math.abs(toDy - curDy)
+      const sX = curDx < toDx ? 1 : -1
+      const sY = curDy < toDy ? 1 : -1
+
+      const nextPosX = coordAt(baseX, baseY, curDx + sX, curDy)
+      const nextPosY = coordAt(baseX, baseY, curDx, curDy + sY)
+
+      if (remX >= remY && remX > 0 && canStepCardinal(curPos.x, curPos.y, nextPosX.x, nextPosX.y)) {
+        curDx += sX
+      } else if (remY > 0 && canStepCardinal(curPos.x, curPos.y, nextPosY.x, nextPosY.y)) {
+        curDy += sY
+      } else if (remX > 0 && canStepCardinal(curPos.x, curPos.y, nextPosX.x, nextPosX.y)) {
+        curDx += sX
+      } else {
+        return false
+      }
+    }
+    return true
+  }
+
+  // Step 1: Resolve effective reachable anchor (anchorX, anchorY)
+  let anchorX = originX
+  let anchorY = originY
+  const originWalkable = isPointWalkable(originX, originY)
+  let playerReachableOffsetsFromOrigin: Set<string> | null = null
+
+  if (
+    isBlocked &&
+    reachableFrom &&
+    Number.isFinite(reachableFrom.x) &&
+    Number.isFinite(reachableFrom.y)
+  ) {
+    const relX = reachableFrom.x - originX
+    const relY = reachableFrom.y - originY
+    const rawStartDx = Math.round((relX / stepX + relY / stepY) / 2)
+    const rawStartDy = Math.round((relY / stepY - relX / stepX) / 2)
+
+    let startNode: { dx: number; dy: number } | null = null
+    const rawStartPos = coordAt(originX, originY, rawStartDx, rawStartDy)
+    if (isPointWalkable(rawStartPos.x, rawStartPos.y)) {
+      startNode = { dx: rawStartDx, dy: rawStartDy }
+    } else if (isPointWalkable(reachableFrom.x, reachableFrom.y)) {
+      for (const c of getIsometricRingCandidates(1)) {
+        const p = coordAt(originX, originY, rawStartDx + c.dx, rawStartDy + c.dy)
+        if (isPointWalkable(p.x, p.y)) {
+          startNode = { dx: rawStartDx + c.dx, dy: rawStartDy + c.dy }
+          break
+        }
+      }
+    } else {
+      for (let r = 1; r <= 2 && startNode === null; r += 1) {
+        for (const c of getIsometricRingCandidates(r)) {
+          const p = coordAt(originX, originY, rawStartDx + c.dx, rawStartDy + c.dy)
+          if (isPointWalkable(p.x, p.y)) {
+            startNode = { dx: rawStartDx + c.dx, dy: rawStartDy + c.dy }
+            break
+          }
+        }
+      }
+    }
+
+    if (startNode !== null) {
+      const distL1 = Math.abs(startNode.dx) + Math.abs(startNode.dy)
+      const directReachable =
+        originWalkable &&
+        distL1 <= 80 &&
+        canGreedyWalkOnLattice(originX, originY, startNode.dx, startNode.dy, 0, 0)
+
+      if (!directReachable && distL1 <= 120) {
+        const margin = Math.max(maxRings + 6, 16)
+        const minDx = Math.min(startNode.dx, 0) - margin
+        const maxDx = Math.max(startNode.dx, 0) + margin
+        const minDy = Math.min(startNode.dy, 0) - margin
+        const maxDy = Math.max(startNode.dy, 0) + margin
+
+        const visited = new Set<string>([`${startNode.dx},${startNode.dy}`])
+        const queue: [number, number][] = [[startNode.dx, startNode.dy]]
+        let head = 0
+        while (head < queue.length && queue.length < 4096) {
+          const [cx, cy] = queue[head++]!
+          const curWorld = coordAt(originX, originY, cx, cy)
+          const neighbors: [number, number][] = [
+            [cx - 1, cy],
+            [cx + 1, cy],
+            [cx, cy - 1],
+            [cx, cy + 1],
+          ]
+          for (const [nx, ny] of neighbors) {
+            if (nx < minDx || nx > maxDx || ny < minDy || ny > maxDy) continue
+            const key = `${nx},${ny}`
+            if (visited.has(key)) continue
+            const nextWorld = coordAt(originX, originY, nx, ny)
+            if (!canStepCardinal(curWorld.x, curWorld.y, nextWorld.x, nextWorld.y)) continue
+            visited.add(key)
+            queue.push([nx, ny])
+          }
+        }
+
+        playerReachableOffsetsFromOrigin = visited
+        if (!visited.has('0,0')) {
+          // Snap anchor to the player-reachable coordinate closest to origin (0, 0)
+          let snapped = false
+          const scanMax = Math.max(maxRings, 20)
+          for (let r = 1; r <= scanMax && !snapped; r += 1) {
+            for (const cand of getIsometricRingCandidates(r)) {
+              if (visited.has(`${cand.dx},${cand.dy}`)) {
+                const pos = coordAt(originX, originY, cand.dx, cand.dy)
+                anchorX = pos.x
+                anchorY = pos.y
+                snapped = true
+                break
+              }
+            }
+          }
+          if (!snapped) {
+            let bestDx = startNode.dx
+            let bestDy = startNode.dy
+            let bestL1 = Math.abs(bestDx) + Math.abs(bestDy)
+            let bestSq = bestDx * bestDx + bestDy * bestDy
+            for (const [vx, vy] of queue) {
+              const l1 = Math.abs(vx) + Math.abs(vy)
+              const sq = vx * vx + vy * vy
+              if (l1 < bestL1 || (l1 === bestL1 && sq < bestSq)) {
+                bestL1 = l1
+                bestSq = sq
+                bestDx = vx
+                bestDy = vy
+              }
+            }
+            const pos = coordAt(originX, originY, bestDx, bestDy)
+            anchorX = pos.x
+            anchorY = pos.y
+          }
+        }
+      }
+    }
+  }
+
+  // If anchor is still on a blocked coordinate (e.g. origin inside thick wall/water/void without reachableFrom),
+  // snap anchor to the nearest walkable floor coordinate with the largest local connected component.
+  if (isBlocked && !isPointWalkable(anchorX, anchorY)) {
+    const measureComponentSize = (startX: number, startY: number, cap = 12): number => {
+      const seen = new Set<string>(['0,0'])
+      const q: [number, number][] = [[0, 0]]
+      let h = 0
+      while (h < q.length && seen.size < cap) {
+        const [qx, qy] = q[h++]!
+        const curW = coordAt(startX, startY, qx, qy)
+        const nbs: [number, number][] = [
+          [qx - 1, qy],
+          [qx + 1, qy],
+          [qx, qy - 1],
+          [qx, qy + 1],
+        ]
+        for (const [nx, ny] of nbs) {
+          const k = `${nx},${ny}`
+          if (seen.has(k)) continue
+          const nextW = coordAt(startX, startY, nx, ny)
+          if (!canStepCardinal(curW.x, curW.y, nextW.x, nextW.y)) continue
+          seen.add(k)
+          q.push([nx, ny])
+          if (seen.size >= cap) break
+        }
+      }
+      return seen.size
+    }
+
+    const escapeRings = Math.max(maxRings, 30)
+    let fallbackWalkable: { x: number; y: number; size: number } | null = null
+    let snapped = false
+    for (let r = 1; r <= escapeRings && !snapped; r += 1) {
+      for (const cand of getIsometricRingCandidates(r)) {
+        const pos = coordAt(originX, originY, cand.dx, cand.dy)
+        if (!isPointWalkable(pos.x, pos.y)) continue
+        const compSize = measureComponentSize(pos.x, pos.y, 8)
+        if (compSize >= 6) {
+          anchorX = pos.x
+          anchorY = pos.y
+          snapped = true
+          break
+        }
+        if (fallbackWalkable === null || compSize > fallbackWalkable.size) {
+          fallbackWalkable = { x: pos.x, y: pos.y, size: compSize }
+        }
+      }
+    }
+    if (!snapped && fallbackWalkable !== null) {
+      anchorX = fallbackWalkable.x
+      anchorY = fallbackWalkable.y
+    }
+  }
+
+  // Step 2: Lazy 4-connected walkable verification around (anchorX, anchorY)
+  const anchorWalkable = isPointWalkable(anchorX, anchorY)
+  let anchorConnectedOffsets: Set<string> | null = null
+
+  const isCandidateConnectedToAnchor = (dx: number, dy: number): boolean => {
+    if (!isBlocked || !anchorWalkable) return true
+    if (dx === 0 && dy === 0) return true
+
+    if (canGreedyWalkOnLattice(anchorX, anchorY, 0, 0, dx, dy)) {
+      return true
+    }
+
+    if (anchorConnectedOffsets === null) {
+      const bound = Math.max(maxRings + 4, 14)
+      anchorConnectedOffsets = new Set<string>(['0,0'])
+      const q: [number, number][] = [[0, 0]]
+      let h = 0
+      while (h < q.length && q.length < 2048) {
+        const [qx, qy] = q[h++]!
+        const curW = coordAt(anchorX, anchorY, qx, qy)
+        const nbs: [number, number][] = [
+          [qx - 1, qy],
+          [qx + 1, qy],
+          [qx, qy - 1],
+          [qx, qy + 1],
+        ]
+        for (const [nx, ny] of nbs) {
+          if (Math.abs(nx) > bound || Math.abs(ny) > bound) continue
+          const k = `${nx},${ny}`
+          if (anchorConnectedOffsets.has(k)) continue
+          const nextW = coordAt(anchorX, anchorY, nx, ny)
+          if (!canStepCardinal(curW.x, curW.y, nextW.x, nextW.y)) continue
+          anchorConnectedOffsets.add(k)
+          q.push([nx, ny])
+        }
+      }
+    }
+
+    return anchorConnectedOffsets.has(`${dx},${dy}`)
+  }
+
+  // Step 3: Concentric diamond ring search around (anchorX, anchorY)
   let firstWalkableCandidate: { x: number; y: number } | null = null
 
   for (let ring = 0; ring <= maxRings; ring += 1) {
     const ringCandidates = getIsometricRingCandidates(ring)
 
     for (const cand of ringCandidates) {
-      // 2:1 Isometric projection screen offset:
-      // cx = originX + (dx - dy) * stepX
-      // cy = originY + (dx + dy) * stepY
-      const cx = originX + (cand.dx - cand.dy) * stepX
-      const cy = originY + (cand.dx + cand.dy) * stepY
+      const cx = anchorX + (cand.dx - cand.dy) * stepX
+      const cy = anchorY + (cand.dx + cand.dy) * stepY
 
-      // Check collision and line of sight
-      if (isDropPositionBlocked(cx, cy, originX, originY, isBlocked)) {
+      // Check collision and line of sight from the walkable anchor
+      if (isDropPositionBlocked(cx, cy, anchorX, anchorY, isBlocked)) {
         continue
       }
 
+      // Check 4-way walkable connectivity to anchor (prevents clipping across walls/corners)
+      if (!isCandidateConnectedToAnchor(cand.dx, cand.dy)) {
+        continue
+      }
+
+      // If player reachability set was computed on origin lattice, verify candidate is also in it
+      if (playerReachableOffsetsFromOrigin !== null && anchorX === originX && anchorY === originY) {
+        if (!playerReachableOffsetsFromOrigin.has(`${cand.dx},${cand.dy}`)) {
+          continue
+        }
+      }
+
       if (firstWalkableCandidate === null) {
         firstWalkableCandidate = { x: cx, y: cy }
       }
@@ -703,7 +1335,7 @@ export function findIsometricDropPosition(
     }
   }
 
-  return firstWalkableCandidate ?? { x: originX, y: originY }
+  return firstWalkableCandidate ?? { x: anchorX, y: anchorY }
 }
 
 /**

src/game/item-cost.ts

@@ -510,7 +510,8 @@ export function calculateTransactionCost(options: TransactionCostOptions): numbe
     nRepCost = afterSkill.repCost
   }
 
-  const isIdentified = item.flags?.identified !== false && !item.isGambleMystery
+  const isIdentified =
+    item.identified !== false && item.flags?.identified !== false && !item.isGambleMystery
 
   if (isIdentified) {
     let nSell = 0

src/game/vendor-generator.ts

@@ -350,6 +350,7 @@ export function generateVendorStoreItem(options: {
     ilvl: nItemLevel,
     dwInitSeed,
     itemRng,
+    identified: true,
   })
 
   // Roll authentic armor defense in [minac, maxac] (or maxac + 1 if enhanced defense)
@@ -779,6 +780,7 @@ export function resolveGambledItem(options: {
     ilvl,
     dwInitSeed,
     itemRng,
+    identified: true,
   })
 
   return {

src/scene/act-scene.ts

@@ -6853,10 +6853,12 @@ async function runScene(initialRuntime: MapRuntime, renderer: SpriteRenderer, st
 
     const here = playerSubTile()
     const candidateOffsets = [
+      { dx: -2, dy: 2 },
+      { dx: -2, dy: 1 },
+      { dx: -1, dy: 2 },
+      { dx: 0, dy: -2 },
       { dx: 2, dy: -1 },
       { dx: 2, dy: 0 },
-      { dx: 0, dy: -2 },
-      { dx: -2, dy: 1 },
       { dx: 1, dy: -1 },
       { dx: 0, dy: 0 },
     ]
@@ -7218,12 +7220,34 @@ async function runScene(initialRuntime: MapRuntime, renderer: SpriteRenderer, st
       await next.loadPages(renderer, next.priorityPages, () => {
         state.pagesLoaded = countLoadedPages(next.pages)
       })
+      let effectiveOverride = override
+      if (isTownLevel(next.levelId) && next.variant) {
+        townVariantByAct.set(next.act, next.variant)
+        const openPortal = portalSlot.current()
+        if (openPortal !== null && openPortal.townLevelId === next.levelId) {
+          const exactTownSub = resolveTownPortalSubTile(next.levelId, next.variant)
+          if (openPortal.townX !== exactTownSub.x || openPortal.townY !== exactTownSub.y) {
+            const wasHeadingToPortal =
+              effectiveOverride !== undefined &&
+              effectiveOverride.x === openPortal.townX &&
+              effectiveOverride.y === openPortal.townY
+            portalSlot.cast({
+              ...openPortal,
+              townX: exactTownSub.x,
+              townY: exactTownSub.y,
+            })
+            if (wasHeadingToPortal) {
+              effectiveOverride = exactTownSub
+            }
+          }
+        }
+      }
       // The destination's own opening back to where we came from is the landing
       // spot; an override wins, because a waypoint or a portal lands somewhere
       // that no edge describes.
       const back = next.entrances.find(entrance => entrance.toLevelId === fromLevelId)
         ?? next.warps.find(warp => warp.toLevelId === fromLevelId)
-      const rawLanding = override
+      const rawLanding = effectiveOverride
         ?? (back === undefined
           ? {
             x: Math.floor(next.grid.cellsX * SUB_TILES_PER_TILE / 2),

src/scene/net-scene.ts

@@ -740,12 +740,33 @@ export function createNetSimulation(
         })
 
         const burstOccupied: { x: number; y: number }[] = ground.map(g => ({ x: g.x, y: g.y }))
+        const alivePlayers = world.players.filter(p => p.alive)
+        const refPlayers = alivePlayers.length > 0 ? alivePlayers : world.players
+        let reachableFrom: { x: number; y: number } | undefined
+        if (refPlayers.length > 0) {
+          let bestPlayer = refPlayers[0]!
+          let bestDist = Math.hypot(bestPlayer.x - event.x, bestPlayer.y - event.y)
+          for (let pIdx = 1; pIdx < refPlayers.length; pIdx += 1) {
+            const p = refPlayers[pIdx]!
+            const d = Math.hypot(p.x - event.x, p.y - event.y)
+            if (d < bestDist) {
+              bestDist = d
+              bestPlayer = p
+            }
+          }
+          reachableFrom = { x: bestPlayer.x, y: bestPlayer.y }
+        }
         for (const drop of droppedItems) {
           const dropPos = findIsometricDropPosition(
             event.x,
             event.y,
             burstOccupied,
             mapTerrain,
+            undefined,
+            undefined,
+            undefined,
+            undefined,
+            reachableFrom,
           )
           burstOccupied.push(dropPos)
           ground.push({ x: dropPos.x, y: dropPos.y, item: drop })

src/ui/ground-labels.ts

@@ -12,8 +12,13 @@
  * - Clickable labels to trigger pathfinding and item pickup.
  */
 
-import type { GroundItemEntity } from '../game/ground-items.ts'
-import { translateItemName, translateRareName, translateMagicName } from '../game/tooltip-i18n.ts'
+import { isGroundSourceUnidentified, type GroundItemEntity } from '../game/ground-items.ts'
+import {
+  resolveBaseItemNameEn,
+  translateItemName,
+  translateRareName,
+  translateMagicName,
+} from '../game/tooltip-i18n.ts'
 
 /**
  * Authentic 1.13c Diablo II quality color codes for ground item labels.
@@ -112,6 +117,31 @@ export function formatGroundItemLabelText(item: GroundItemEntity): string {
   if (item.isGold) {
     return `${item.amount} 金币`
   }
+  const src = item.item as any
+  if (isGroundSourceUnidentified(src)) {
+    const baseObj = src?.base ?? src?.rawItem?.base ?? src?.item?.base
+    const rawCode =
+      typeof src?.code === 'string'
+        ? src.code.trim().toLowerCase()
+        : typeof baseObj?.id === 'string'
+          ? baseObj.id.trim().toLowerCase()
+          : ''
+    const rawBaseName =
+      typeof baseObj?.name === 'string' && baseObj.name.trim().length > 0
+        ? baseObj.name
+        : item.name
+    if (rawBaseName) {
+      const baseNameEn = resolveBaseItemNameEn(rawBaseName, rawCode)
+      if (item.nameZh && item.name === baseNameEn) {
+        return item.nameZh
+      }
+      const translatedBase =
+        translateItemName(rawBaseName) !== rawBaseName
+          ? translateItemName(rawBaseName)
+          : translateItemName(baseNameEn)
+      return translatedBase || baseNameEn
+    }
+  }
   if (item.nameZh) {
     return item.nameZh
   }

src/ui/hud-manager.ts

@@ -748,10 +748,17 @@ export class HudManager {
           }
         }
       }
+
+      const intercept =
+        this.isPointInterceptedByHud(this.mouseX, this.mouseY) || this.inventory.cursorItem !== null
+      this.hudCanvas.style.pointerEvents = intercept ? 'auto' : 'none'
     })
 
-    window.addEventListener('mousedown', () => {
+    window.addEventListener('mousedown', (e) => {
       this.cursor.handleMouseDown()
+      if (e.target !== this.hudCanvas && e.target instanceof HTMLCanvasElement) {
+        handleHudMouseDown(e)
+      }
     })
 
     window.addEventListener('mouseup', () => {
@@ -763,7 +770,7 @@ export class HudManager {
       e.preventDefault()
     })
 
-    this.hudCanvas.addEventListener('mousedown', (e) => {
+    const handleHudMouseDown = (e: MouseEvent): void => {
       if (e.button !== 0 && e.button !== 2) return
       const pt = this.clientToLogical(e.clientX, e.clientY)
       if (this.worldPanels.npcMenu && !this.worldPanels.isPointInNpcMenu(pt.x, pt.y, this.font)) {
@@ -1008,7 +1015,9 @@ export class HudManager {
           return
         }
       }
-    })
+    }
+
+    this.hudCanvas.addEventListener('mousedown', handleHudMouseDown)
   }
 
   private handleSkillAllocated(skillId: number): void {

src/ui/inventory.ts

@@ -39,6 +39,7 @@ export interface UiInventoryItem {
   readonly id: string
   readonly code: string
   readonly invFile: string
+  readonly baseInvFile?: string | undefined
   readonly name: string
   readonly nameZh: string
   readonly baseNameZh: string
@@ -146,6 +147,7 @@ export interface ResolvableItem {
   readonly nameZh?: string | undefined
   readonly baseNameZh?: string | undefined
   readonly invFile?: string | undefined
+  readonly baseInvFile?: string | undefined
   readonly flippyFile?: string | undefined
   readonly isGold?: boolean | undefined
   readonly amount?: number | undefined
@@ -158,6 +160,9 @@ export interface ResolvableItem {
   readonly invHeight?: number | undefined
   readonly width?: number | undefined
   readonly height?: number | undefined
+  readonly identified?: boolean | undefined
+  readonly isGambleMystery?: boolean | undefined
+  readonly rawItem?: Item | undefined
 }
 
 /**
@@ -179,7 +184,28 @@ export function resolveItemSpriteRect(
   itemRects: Record<string, SpriteRect> = BAKED_UI_MANIFEST.itemRects,
 ): SpriteRect | null {
   const normalizedCode = normalizeItemCode(rawItem)
-  const item: ResolvableItem = normalizedCode === rawItem.code ? rawItem : { ...rawItem, code: normalizedCode }
+  const normalizedItem: ResolvableItem =
+    normalizedCode === rawItem.code ? rawItem : { ...rawItem, code: normalizedCode }
+  const isUnid = Boolean(
+    normalizedItem.identified === false ||
+      normalizedItem.isGambleMystery === true ||
+      normalizedItem.rawItem?.identified === false ||
+      normalizedItem.rawItem?.isGambleMystery === true ||
+      (normalizedItem.rawItem?.flags !== undefined && normalizedItem.rawItem.flags.identified === false),
+  )
+  // Per D2Client.dll, unidentified items render their base item graphic without unique/set invfile or dye transform
+  const item: ResolvableItem = isUnid
+    ? {
+        ...normalizedItem,
+        invFile:
+          normalizedItem.baseInvFile ??
+          (normalizedItem.code && BAKED_UI_MANIFEST.codeToInvFile[normalizedItem.code]
+            ? BAKED_UI_MANIFEST.codeToInvFile[normalizedItem.code]
+            : normalizedItem.invFile),
+        invtransform: undefined,
+        name: normalizedItem.rawItem?.base?.name ?? undefined,
+      }
+    : normalizedItem
   // Tier 0: Transformed dyed item lookup: `${invFile}_${invtransform}`
   const targetInv =
     item.invFile ||
@@ -1056,6 +1082,8 @@ export function identifyUiItem(item: UiInventoryItem): UiInventoryItem {
     }
     const rebuilt = itemToUiInventoryItem(item.rawItem)
     Object.assign(item, {
+      invFile: rebuilt.invFile,
+      ...(rebuilt.baseInvFile !== undefined ? { baseInvFile: rebuilt.baseInvFile } : {}),
       name: rebuilt.name,
       nameZh: rebuilt.nameZh,
       baseNameZh: rebuilt.baseNameZh,
@@ -1645,8 +1673,9 @@ export class InventoryPanel {
       const gw = placed.item.invWidth * INV_GRID_ORIGIN.cellPx
       const gh = placed.item.invHeight * INV_GRID_ORIGIN.cellPx
 
-      ctx.fillStyle =
-        placed.item.quality === 'unique'
+      ctx.fillStyle = isUiItemUnidentified(placed.item)
+        ? 'rgba(72, 18, 18, 0.50)'
+        : placed.item.quality === 'unique'
           ? 'rgba(58, 42, 16, 0.45)'
           : placed.item.quality === 'set'
             ? 'rgba(16, 52, 22, 0.45)'

src/ui/item-bridge.ts

@@ -383,6 +383,12 @@ export function itemToUiInventoryItem(
 
   // 3. invFile & Dye Resolution
   const { invFile, invtransform, chrtransform } = resolveItemInvFile(rawItem, quality, code, dropTables)
+  const { invFile: baseInvFile } = resolveItemInvFile(
+    { ...rawItem, name: baseEn, uniqueItemDef: undefined, setItemDef: undefined } as Item,
+    'normal',
+    code,
+    dropTables,
+  )
 
   // 4. Allowed Equipment Slots
   const allowedSlots = resolveAllowedSlots(
@@ -494,6 +500,7 @@ export function itemToUiInventoryItem(
     id,
     code,
     invFile,
+    baseInvFile,
     name: rawItem.name || baseEn,
     nameZh,
     baseNameZh,

src/ui/skill-tree-panel.ts

@@ -41,7 +41,22 @@ export interface SkillNodeDef {
 }
 
 export const SKILL_PANEL_ORIGIN = { x: 400, y: 60, width: 320, height: 432 } as const
-export const SKILL_CLOSE_BTN_BOUNDS = { x: 400 + 272, y: 60 + 388, w: 32, h: 32 } as const
+
+/**
+ * Authentic D2 v1.13c (`skltree_*_back.DC6` frames 6, 10, 14) 32x32 Close Button socket X offsets
+ * per class and tab `[tab0, tab1, tab2]` relative to `SKILL_PANEL_ORIGIN.x` (Y offset is always +385).
+ */
+export const SKILL_CLOSE_BTN_OFFSET_X: Record<CharacterClassCode, readonly [number, number, number]> = {
+  ama: [171, 101, 16],
+  sor: [16, 16, 171],
+  nec: [16, 171, 16],
+  pal: [16, 101, 16],
+  bar: [171, 16, 171],
+  dru: [171, 171, 171],
+  ass: [101, 171, 16],
+}
+
+export const SKILL_CLOSE_BTN_BOUNDS = { x: 400 + 171, y: 60 + 385, w: 32, h: 32 } as const
 
 /** Authentic D2Client.dll 1.13c ground truth grid offsets inside panel (ox=400, oy=60). */
 export const SKILL_TREE_COL_OFFSETS_X = [15, 84, 153] as const
@@ -287,6 +302,17 @@ export class SkillTreePanel {
     return { x, y, w: 48, h: 48 }
   }
 
+  getCloseButtonBounds(): { x: number; y: number; w: number; h: number } {
+    const offsets = SKILL_CLOSE_BTN_OFFSET_X[this.characterClass] ?? SKILL_CLOSE_BTN_OFFSET_X.sor
+    const offsetX = offsets[this.activeTab] ?? 171
+    return {
+      x: SKILL_PANEL_ORIGIN.x + offsetX,
+      y: SKILL_PANEL_ORIGIN.y + 385,
+      w: 32,
+      h: 32,
+    }
+  }
+
   handleMouseMove(logicalX: number, logicalY: number): void {
     this.hoveredSkill = null
     if (!this.visible) return
@@ -304,19 +330,20 @@ export class SkillTreePanel {
     if (!this.visible) return false
     if (logicalX < 400) return false
 
-    // Close button
+    // Close button (authentic per-class/per-tab 32x32 stone socket at y = oy + 385)
+    const closeBounds = this.getCloseButtonBounds()
     if (
-      logicalX >= SKILL_CLOSE_BTN_BOUNDS.x &&
-      logicalX <= SKILL_CLOSE_BTN_BOUNDS.x + SKILL_CLOSE_BTN_BOUNDS.w &&
-      logicalY >= SKILL_CLOSE_BTN_BOUNDS.y &&
-      logicalY <= SKILL_CLOSE_BTN_BOUNDS.y + SKILL_CLOSE_BTN_BOUNDS.h
+      logicalX >= closeBounds.x &&
+      logicalX <= closeBounds.x + closeBounds.w &&
+      logicalY >= closeBounds.y &&
+      logicalY <= closeBounds.y + closeBounds.h
     ) {
       this.visible = false
       return true
     }
 
-    // Right vertical tabs (`x = 656..720`)
-    if (logicalX >= 656 && logicalX <= 720) {
+    // Right vertical tabs (`x = 630..720`, full 90px tab column `ox + 230..320`)
+    if (logicalX >= SKILL_PANEL_ORIGIN.x + 230 && logicalX <= SKILL_PANEL_ORIGIN.x + 320) {
       const vTabs = this.getVerticalTabs()
       if (logicalY >= 60 + 95 && logicalY < 60 + 195 && vTabs[0]) {
         this.activeTab = vTabs[0].tab
@@ -326,7 +353,7 @@ export class SkillTreePanel {
         this.activeTab = vTabs[1].tab
         return true
       }
-      if (logicalY >= 60 + 295 && logicalY < 60 + 385 && vTabs[2]) {
+      if (logicalY >= 60 + 295 && logicalY <= 60 + 432 && vTabs[2]) {
         this.activeTab = vTabs[2].tab
         return true
       }
@@ -369,7 +396,8 @@ export class SkillTreePanel {
 
     // 2. Draw 256x432 Skill Tree Tab Background (`bg_sor_<tab>.png`)
     const bg = this.tabBgs.get(this.activeTab)
-    if (bg && bg.complete && bg.naturalWidth > 0) {
+    const hasBg = Boolean(bg && bg.complete && bg.naturalWidth > 0)
+    if (hasBg && bg) {
       ctx.drawImage(bg, ox, oy, 256, 432)
     } else {
       ctx.fillStyle = '#181410'
@@ -381,7 +409,10 @@ export class SkillTreePanel {
     const tabColIdx = verticalTabs.findIndex(vt => vt.tab === this.activeTab)
     const safeColIdx = tabColIdx >= 0 ? tabColIdx : 0
 
-    if (assets.skillTabsImg && assets.skillTabsImg.complete && assets.skillTabsImg.naturalWidth > 0) {
+    const hasTabsImg = Boolean(
+      assets.skillTabsImg && assets.skillTabsImg.complete && assets.skillTabsImg.naturalWidth > 0,
+    )
+    if (hasTabsImg && assets.skillTabsImg) {
       ctx.drawImage(assets.skillTabsImg, safeColIdx * 64, 0, 64, 432, ox + 256, oy, 64, 432)
     } else {
       ctx.fillStyle = '#14110d'
@@ -390,38 +421,28 @@ export class SkillTreePanel {
       ctx.strokeRect(ox + 256.5, oy + 0.5, 63, 431)
     }
 
-    // Remaining Skill Points Header Box
-    font.drawText(ctx, '剩余技能点', ox + 288, oy + 26, {
+    // Remaining Skill Points Header Plaque (built-in DC6 recessed stone box at x=255..297, y=61..83)
+    font.drawText(ctx, '剩余技能点', ox + 276, oy + 38, {
       font: 'font8',
       color: 'gold',
       align: 'center',
     })
-    ctx.fillStyle = '#080605'
-    ctx.fillRect(ox + 270, oy + 34, 36, 24)
-    ctx.strokeStyle = '#8c7244'
-    ctx.strokeRect(ox + 270.5, oy + 34.5, 35, 23)
-    font.drawText(ctx, String(this.unspentSkillPoints), ox + 288, oy + 52, {
+    if (!hasTabsImg) {
+      ctx.fillStyle = '#080605'
+      ctx.fillRect(ox + 255, oy + 61, 43, 23)
+      ctx.strokeStyle = '#8c7244'
+      ctx.strokeRect(ox + 255.5, oy + 61.5, 42, 22)
+    }
+    font.drawText(ctx, String(this.unspentSkillPoints), ox + 276, oy + 78, {
       font: 'font16',
       color: this.unspentSkillPoints > 0 ? 'red' : 'white',
       align: 'center',
     })
 
-    // Remaining Skill Points Banner (Authentic D2 skillpoints.dc6 banner at bottom of tree)
-    if (this.unspentSkillPoints > 0 && assets.skillPointsImg && assets.skillPointsImg.complete && assets.skillPointsImg.naturalWidth > 0) {
-      const spX = ox + Math.round((256 - 135) / 2)
-      const spY = oy + 395
-      ctx.drawImage(assets.skillPointsImg, spX, spY, 135, 23)
-      font.drawText(ctx, String(this.unspentSkillPoints), spX + 112, spY + 16, {
-        font: 'font16',
-        color: 'red',
-        align: 'center',
-      })
-    }
-
-    // 3 Vertical Tabs for Active Class
+    // 3 Vertical Tabs for Active Class (90px column x=230..319, center ox + 275)
     for (const vt of verticalTabs) {
       const active = this.activeTab === vt.tab
-      if (!assets.skillTabsImg || !assets.skillTabsImg.complete || assets.skillTabsImg.naturalWidth === 0) {
+      if (!hasTabsImg) {
         // Authentic stone-beveled fallback when texture atlas is unavailable
         ctx.fillStyle = active ? '#382e22' : '#1b1610'
         ctx.fillRect(ox + 258, oy + vt.y, 60, 96)
@@ -429,12 +450,12 @@ export class SkillTreePanel {
         ctx.lineWidth = active ? 2 : 1
         ctx.strokeRect(ox + 258.5, oy + vt.y + 0.5, 59, 95)
       }
-      font.drawText(ctx, vt.titleZh, ox + 288, oy + vt.y + 42, {
+      font.drawText(ctx, vt.titleZh, ox + 275, oy + vt.y + 52, {
         font: 'fontexocet10',
         color: active ? 'gold' : 'tan',
         align: 'center',
       })
-      font.drawText(ctx, vt.subZh, ox + 288, oy + vt.y + 62, {
+      font.drawText(ctx, vt.subZh, ox + 275, oy + vt.y + 72, {
         font: 'fontexocet10',
         color: active ? 'gold' : 'tan',
         align: 'center',
@@ -465,28 +486,31 @@ export class SkillTreePanel {
         ctx.strokeRect(pos.x + 0.5, pos.y + 0.5, 47, 47)
       }
 
-      // Level Badge in bottom-right corner of the 48x48 skill icon
-      ctx.fillStyle = '#090705'
-      ctx.fillRect(pos.x + 34, pos.y + 34, 20, 16)
-      ctx.strokeStyle = '#6c5838'
-      ctx.strokeRect(pos.x + 34.5, pos.y + 34.5, 19, 15)
-      font.drawText(ctx, String(eff), pos.x + 44, pos.y + 46, {
+      // Level socket: built-in DC6 stone socket has dark interior at pos.x + 42..60, pos.y + 50..60
+      if (!hasBg) {
+        ctx.fillStyle = '#090705'
+        ctx.fillRect(pos.x + 42, pos.y + 50, 19, 11)
+        ctx.strokeStyle = '#6c5838'
+        ctx.strokeRect(pos.x + 41.5, pos.y + 49.5, 20, 12)
+      }
+      font.drawText(ctx, String(eff), pos.x + 51, pos.y + 59, {
         font: 'font8',
         color: eff > hard ? 'blue' : hard > 0 ? 'white' : 'gray',
         align: 'center',
       })
     }
 
-    // 5. Close Button (`buysellbtn.dc6` frame 10)
+    // 5. Close Button (`buysellbtn.dc6` frame 10 in authentic per-tab 32x32 DC6 stone socket)
     if (assets.buySellBtnImg) {
+      const closeBounds = this.getCloseButtonBounds()
       ctx.drawImage(
         assets.buySellBtnImg,
         10 * 32,
         0,
         32,
         32,
-        SKILL_CLOSE_BTN_BOUNDS.x,
-        SKILL_CLOSE_BTN_BOUNDS.y,
+        closeBounds.x,
+        closeBounds.y,
         32,
         32,
       )

src/ui/world-panels.ts

@@ -47,6 +47,45 @@ export const STASH_CLOSE_BTN_BOUNDS = { x: 80 + 272, y: 60 + 388, w: 32, h: 32 }
 export const STASH_DEPOSIT_BTN_BOUNDS = { x: 80 + 68, y: 60 + 386, w: 76, h: 26 } as const
 export const STASH_WITHDRAW_BTN_BOUNDS = { x: 80 + 154, y: 60 + 386, w: 76, h: 26 } as const
 
+/**
+ * `Panel\TradeStash.dc6` (`public/ui/stash-bg.png`, 320x432 anchored at `ox = 80, oy = 60`)
+ * header recessed dark boxes (Issue #493):
+ * - Top box (`relY = 24..38`, height 15px) is divided by a vertical bar at `relX = 94..96` into:
+ *   - Left icon socket: `relX = 74..93, relY = 24..38` (20x15px)
+ *   - Right title text recess: `relX = 97..247, relY = 24..38` (151x15px, center `relX = 172, relY = 31`, alphabetic baseline `oy + 35`)
+ * - Bottom gold text recess: `relX = 75..246, relY = 49..65` (172x17px, center `relX = 160, relY = 57`, alphabetic baseline `oy + 61`)
+ */
+export const STASH_HEADER_ICON_SOCKET = {
+  x: 80 + 74,
+  y: 60 + 24,
+  relX: 74,
+  relY: 24,
+  w: 20,
+  h: 15,
+} as const
+
+export const STASH_HEADER_TOP_RECESS = {
+  x: 80 + 97,
+  y: 60 + 24,
+  relX: 97,
+  relY: 24,
+  w: 151,
+  h: 15,
+  textX: 80 + 172,
+  textY: 60 + 35,
+} as const
+
+export const STASH_HEADER_BOTTOM_RECESS = {
+  x: 80 + 75,
+  y: 60 + 49,
+  relX: 75,
+  relY: 49,
+  w: 172,
+  h: 17,
+  textX: 80 + 160,
+  textY: 60 + 61,
+} as const
+
 /** `Inventory.txt` `Transmogrify Box Page 1` / `Transmogrify Box2` (`supertransmogrifier.dc6` 3x4 grid) */
 export const CUBE_PANEL_ORIGIN = { x: 80, y: 60, width: 320, height: 432, w: 320, h: 432 } as const
 export const CUBE_GRID_ORIGIN = { x: 80 + 117, y: 60 + 139, cols: 3, rows: 4, cellPx: 29 } as const
@@ -2126,12 +2165,12 @@ export class WorldPanelsHud {
       }
     } else if (kind === 'stash') {
       if (assets.stashBgImg) ctx.drawImage(assets.stashBgImg, ox, oy)
-      font.drawText(ctx, '私人储物箱 (Private Stash)', ox + 160, oy + 26, {
-        font: 'fontexocet10',
+      font.drawText(ctx, '私人储物箱 (Private Stash)', ox + 172, oy + 35, {
+        font: 'font8',
         color: 'gold',
         align: 'center',
       })
-      font.drawText(ctx, `储物箱金币: ${this.stashGold.toLocaleString()}`, ox + 160, oy + 48, {
+      font.drawText(ctx, `储物箱金币: ${this.stashGold.toLocaleString()}`, ox + 160, oy + 61, {
         font: 'font8',
         color: 'white',
         align: 'center',
@@ -2612,12 +2651,19 @@ export class WorldPanelsHud {
                 : 'white'
 
     // Header: Title, Runeword Runes line, Base item name
-    lines.push({ text: item.nameZh, color: titleColor, font: 'fontexocet10' })
-    if (item.runewordRunes) {
-      lines.push({ text: item.runewordRunes, color: 'gold', font: 'font8' })
-    }
-    if (item.baseNameZh) {
-      lines.push({ text: item.baseNameZh, color: 'white', font: 'font8' })
+    const unid = isUiItemUnidentified(item)
+    if (unid) {
+      const maskedBaseHeader =
+        (item.baseNameZh ? item.baseNameZh.split(' · ')[0] : undefined) || item.nameZh
+      lines.push({ text: maskedBaseHeader, color: titleColor, font: 'fontexocet10' })
+    } else {
+      lines.push({ text: item.nameZh, color: titleColor, font: 'fontexocet10' })
+      if (item.runewordRunes) {
+        lines.push({ text: item.runewordRunes, color: 'gold', font: 'font8' })
+      }
+      if (item.baseNameZh) {
+        lines.push({ text: item.baseNameZh, color: 'white', font: 'font8' })
+      }
     }
 
     // Vendor Transaction Cost Line (`ITEMS_CalculateTransactionCost` at 0x6FD9B1C0)
@@ -2659,33 +2705,52 @@ export class WorldPanelsHud {
     if (item.reqStr !== undefined) {
       lines.push({ text: '需要力量: ' + item.reqStr, color: 'white', font: 'font8' })
     }
-    if (item.reqLevel !== undefined) {
-      lines.push({ text: '需要等级: ' + item.reqLevel, color: 'white', font: 'font8' })
+    const displayReqLevel = unid
+      ? item.rawItem?.base?.level && item.rawItem.base.level > 1
+        ? item.rawItem.base.level
+        : undefined
+      : item.reqLevel
+    if (displayReqLevel !== undefined) {
+      lines.push({ text: '需要等级: ' + displayReqLevel, color: 'white', font: 'font8' })
     }
 
-    // Magic Affixes
-    for (const st of item.stats) {
-      lines.push({ text: st.text, color: st.color ?? 'blue', font: 'font8' })
-    }
-
-    // Sockets Block
-    if (
-      item.sockets !== undefined &&
-      item.sockets > 0 &&
-      !item.stats.some(s => s.text.includes('凹槽') || s.text.includes('Socketed'))
-    ) {
-      lines.push({ text: '凹槽 (' + item.sockets + ')', color: 'blue', font: 'font8' })
-    }
-
-    // Set Pieces & Set Bonuses Block
-    if (item.setPieces) {
-      for (const piece of item.setPieces) {
-        lines.push({ text: piece, color: 'gray', font: 'font8' })
+    if (unid) {
+      if (item.isGambleMystery) {
+        lines.push({ text: '未鉴定 (Unidentified Gamble Item)', color: 'red', font: 'font8' })
+      } else {
+        lines.push({ text: '未辨识 (Unidentified)', color: 'red', font: 'font8' })
+        if (item.allowedSlots.length > 0) {
+          lines.push({ text: '无法使用 (Cannot be Equipped)', color: 'red', font: 'font8' })
+        }
+        if (item.ethereal) {
+          lines.push({ text: '无形的 (无法修复) (Ethereal)', color: 'blue', font: 'font8' })
+        }
       }
-    }
-    if (item.setBonuses) {
-      for (const bonus of item.setBonuses) {
-        lines.push({ text: bonus.text, color: bonus.color ?? 'green', font: 'font8' })
+    } else {
+      // Magic Affixes
+      for (const st of item.stats) {
+        lines.push({ text: st.text, color: st.color ?? 'blue', font: 'font8' })
+      }
+
+      // Sockets Block
+      if (
+        item.sockets !== undefined &&
+        item.sockets > 0 &&
+        !item.stats.some(s => s.text.includes('凹槽') || s.text.includes('Socketed'))
+      ) {
+        lines.push({ text: '凹槽 (' + item.sockets + ')', color: 'blue', font: 'font8' })
+      }
+
+      // Set Pieces & Set Bonuses Block
+      if (item.setPieces) {
+        for (const piece of item.setPieces) {
+          lines.push({ text: piece, color: 'gray', font: 'font8' })
+        }
+      }
+      if (item.setBonuses) {
+        for (const bonus of item.setBonuses) {
+          lines.push({ text: bonus.text, color: bonus.color ?? 'green', font: 'font8' })
+        }
       }
     }
 

tests/ground-items-reachability.test.ts

@@ -0,0 +1,324 @@
+import { describe, expect, it } from 'vitest'
+import {
+  COLLIDE_MASK_DROP_BLOCK,
+  findIsometricDropPosition,
+  findSafeDropPosition,
+  isDropPositionBlocked,
+  isTerrainPointBlocked,
+  isWithinPickupBounds,
+} from '../src/game/ground-items.ts'
+import {
+  COLLIDE_BLANK,
+  COLLIDE_DOOR,
+  COLLIDE_MASK_INVALID,
+  COLLIDE_NO_PATH,
+  COLLIDE_NONE,
+  COLLIDE_NOPLAYER,
+  COLLIDE_OBJECT,
+  COLLIDE_WALL,
+  COLLIDE_WATER,
+  ORTHO_CELL_HEIGHT,
+  ORTHO_CELL_WIDTH,
+  ORTHO_SUB_TILE_HEIGHT,
+  ORTHO_SUB_TILE_WIDTH,
+  getCollisionMaskAt,
+  isBlockedAt,
+  subTileAt,
+  subTileCentre,
+  type CollisionGrid,
+} from '../src/game/d2map.ts'
+import { createIsoTerrain } from '../src/game/iso-terrain.ts'
+import { GameEngine } from '../src/game/engine.ts'
+
+function createSubTileGrid(cellsX = 12, cellsY = 12): CollisionGrid {
+  const gridWidth = cellsX * 5
+  const gridHeight = cellsY * 5
+  return {
+    cellsX,
+    cellsY,
+    gridWidth,
+    originX: cellsY * ORTHO_CELL_WIDTH,
+    originY: 0,
+    blocked: new Uint8Array(gridWidth * gridHeight),
+    collisionMasks: new Uint16Array(gridWidth * gridHeight),
+  }
+}
+
+function setSubTileMask(grid: CollisionGrid, subX: number, subY: number, mask: number): void {
+  const idx = subY * grid.gridWidth + subX
+  if (grid.collisionMasks) {
+    grid.collisionMasks[idx] = mask
+  }
+  grid.blocked[idx] = (mask & (COLLIDE_WALL | COLLIDE_BLANK | COLLIDE_NOPLAYER | COLLIDE_WATER | COLLIDE_DOOR | COLLIDE_OBJECT)) !== 0 ? 1 : 0
+}
+
+describe('Issue #492: Prevent Ground Items & Gold from Dropping into Unreachable Locations', () => {
+  describe('1. Blocked Origin Escape (Monster Dying Inside Thick Walls / Void / Water)', () => {
+    it('escapes a 4x4 solid wall block instead of poisoning rayTraceScene and falling back to blocked origin', () => {
+      const grid = createSubTileGrid(12, 12)
+      // Block a 5x5 sub-tile block around sub-tile (25, 25)
+      for (let sy = 23; sy <= 27; sy += 1) {
+        for (let sx = 23; sx <= 27; sx += 1) {
+          setSubTileMask(grid, sx, sy, COLLIDE_WALL)
+        }
+      }
+
+      const origin = subTileCentre(grid, 25, 25)
+      expect(isTerrainPointBlocked(origin.x, origin.y, grid)).toBe(true)
+
+      const dropPos = findIsometricDropPosition(origin.x, origin.y, [], grid)
+      expect(isTerrainPointBlocked(dropPos.x, dropPos.y, grid)).toBe(false)
+      expect(getCollisionMaskAt(grid, dropPos.x, dropPos.y) & COLLIDE_MASK_DROP_BLOCK).toBe(0)
+      expect(isBlockedAt(grid, dropPos.x, dropPos.y)).toBe(false)
+    })
+
+    it('escapes deeply buried origin (> 10 rings inside void/water) to nearest walkable floor', () => {
+      const grid = createSubTileGrid(16, 16)
+      // Block sub-tiles [15..45, 15..45] (radius 15 > default maxRings=10 around (30, 30))
+      for (let sy = 15; sy <= 45; sy += 1) {
+        for (let sx = 15; sx <= 45; sx += 1) {
+          setSubTileMask(grid, sx, sy, COLLIDE_WATER)
+        }
+      }
+
+      const buriedOrigin = subTileCentre(grid, 30, 30)
+      expect(isTerrainPointBlocked(buriedOrigin.x, buriedOrigin.y, grid)).toBe(true)
+
+      const dropPos = findIsometricDropPosition(buriedOrigin.x, buriedOrigin.y, [], grid)
+      expect(isTerrainPointBlocked(dropPos.x, dropPos.y, grid)).toBe(false)
+      expect(getCollisionMaskAt(grid, dropPos.x, dropPos.y) & COLLIDE_MASK_DROP_BLOCK).toBe(0)
+    })
+  })
+
+  describe('2. Player Path-Connectivity (`reachableFrom`) Across Rivers, Moats & Sealed Rooms', () => {
+    it('snaps drops from a monster killed across an impassable river onto the player side of the river', () => {
+      const grid = createSubTileGrid(12, 12)
+      // Create a full north-south river at subX = 24..27 across the entire map height
+      for (let sy = 0; sy < 60; sy += 1) {
+        for (let sx = 24; sx <= 27; sx += 1) {
+          setSubTileMask(grid, sx, sy, COLLIDE_WATER | COLLIDE_WALL)
+        }
+      }
+
+      // Player is on the West bank (subX = 20, subY = 30)
+      const playerPos = subTileCentre(grid, 20, 30)
+      // Flying/ranged monster dies on the East bank (subX = 32, subY = 30) across the river
+      const monsterDeathPos = subTileCentre(grid, 32, 30)
+
+      expect(isTerrainPointBlocked(playerPos.x, playerPos.y, grid)).toBe(false)
+      expect(isTerrainPointBlocked(monsterDeathPos.x, monsterDeathPos.y, grid)).toBe(false)
+
+      const existing: { x: number; y: number }[] = []
+      for (let i = 0; i < 6; i += 1) {
+        const dropPos = findIsometricDropPosition(
+          monsterDeathPos.x,
+          monsterDeathPos.y,
+          existing,
+          grid,
+          ORTHO_SUB_TILE_WIDTH,
+          ORTHO_SUB_TILE_HEIGHT,
+          10,
+          16,
+          playerPos,
+        )
+        existing.push(dropPos)
+
+        const dropSub = subTileAt(grid, dropPos.x, dropPos.y)
+        // Every dropped item must land on the West bank (subX < 24) where the player can reach it
+        expect(dropSub.subX).toBeLessThan(24)
+        expect(isTerrainPointBlocked(dropPos.x, dropPos.y, grid)).toBe(false)
+      }
+    })
+
+    it('never leaks items through a thin 1-sub-tile wall into an adjacent sealed room during a 15-item burst drop', () => {
+      const grid = createSubTileGrid(12, 12)
+      // Seal a 3x3 sub-tile room at subX = 20..22, subY = 20..22 with a 1-sub-tile wall ring at 19..23
+      for (let sy = 19; sy <= 23; sy += 1) {
+        for (let sx = 19; sx <= 23; sx += 1) {
+          const isInterior = sx >= 20 && sx <= 22 && sy >= 20 && sy <= 22
+          if (!isInterior) {
+            setSubTileMask(grid, sx, sy, COLLIDE_WALL)
+          }
+        }
+      }
+
+      // Exterior floor (subX < 19 or > 23) is completely open, but separated by the wall ring
+      const roomCenter = subTileCentre(grid, 21, 21)
+      const existing: { x: number; y: number }[] = []
+
+      for (let i = 0; i < 15; i += 1) {
+        const pos = findIsometricDropPosition(
+          roomCenter.x,
+          roomCenter.y,
+          existing,
+          grid,
+          ORTHO_SUB_TILE_WIDTH,
+          ORTHO_SUB_TILE_HEIGHT,
+          10,
+          16,
+          roomCenter,
+        )
+        existing.push(pos)
+        const sub = subTileAt(grid, pos.x, pos.y)
+        expect(sub.subX).toBeGreaterThanOrEqual(20)
+        expect(sub.subX).toBeLessThanOrEqual(22)
+        expect(sub.subY).toBeGreaterThanOrEqual(20)
+        expect(sub.subY).toBeLessThanOrEqual(22)
+      }
+    })
+  })
+
+  describe('3. Diagonal Wall-Corner Pinch Prevention', () => {
+    it('rejects diagonal step when both shared orthogonal neighbors are wall sub-tiles', () => {
+      const grid = createSubTileGrid(10, 10)
+      // Origin at (25, 25). Block (26, 25) and (25, 26) so diagonal (26, 26) is pinched by orthogonal walls.
+      setSubTileMask(grid, 26, 25, COLLIDE_WALL)
+      setSubTileMask(grid, 25, 26, COLLIDE_WALL)
+
+      const origin = subTileCentre(grid, 25, 25)
+      const diagTarget = subTileCentre(grid, 26, 26)
+
+      expect(isTerrainPointBlocked(diagTarget.x, diagTarget.y, grid)).toBe(false)
+      expect(isDropPositionBlocked(diagTarget.x, diagTarget.y, origin.x, origin.y, grid)).toBe(true)
+    })
+
+    it('rejects diagonal cell in findSafeDropPosition when sealed by orthogonal wall cells', () => {
+      const width = 5
+      const height = 5
+      const collisionMasks = new Uint16Array(width * height).fill(COLLIDE_WALL)
+      // Open (2, 2) and (3, 3), but keep (3, 2) and (2, 3) as COLLIDE_WALL so (3, 3) is diagonally pinched
+      collisionMasks[2 * width + 2] = COLLIDE_NONE
+      collisionMasks[3 * width + 3] = COLLIDE_NONE
+      const grid = { width, height, collisionMasks }
+
+      // Occupy (2, 2) so findSafeDropPosition searches Ring 1
+      const pos = findSafeDropPosition(grid, 2, 2, 2, [{ cellX: 2, cellY: 2 }])
+      // Must NOT jump diagonally into the sealed (3, 3) pocket; instead stacks safely on (2, 2)
+      expect(pos.cellX).toBe(2)
+      expect(pos.cellY).toBe(2)
+    })
+  })
+
+  describe('4. Full Collision Mask & CountingTerrain Player Footprint Clearance', () => {
+    it('rejects COLLIDE_WATER, COLLIDE_NOPLAYER, COLLIDE_BLANK, COLLIDE_NO_PATH, and COLLIDE_MASK_INVALID', () => {
+      const forbiddenMasks = [
+        COLLIDE_WATER,
+        COLLIDE_NOPLAYER,
+        COLLIDE_BLANK,
+        COLLIDE_NO_PATH,
+        COLLIDE_MASK_INVALID,
+        COLLIDE_DOOR,
+        COLLIDE_OBJECT,
+      ]
+
+      for (const mask of forbiddenMasks) {
+        const grid = createSubTileGrid(8, 8)
+        setSubTileMask(grid, 20, 20, mask)
+        const pt = subTileCentre(grid, 20, 20)
+        expect(isTerrainPointBlocked(pt.x, pt.y, grid)).toBe(true)
+
+        const drop = findIsometricDropPosition(pt.x, pt.y, [], grid)
+        expect(drop).not.toEqual(pt)
+        expect(isTerrainPointBlocked(drop.x, drop.y, grid)).toBe(false)
+      }
+    })
+
+    it('enforces CountingTerrain.overlap(x, y) === 0 in both findIsometricDropPosition and findSafeDropPosition', () => {
+      const grid = createSubTileGrid(10, 10)
+      const terrain = createIsoTerrain(grid, 800, 800, { width: 20, height: 10 })
+
+      // Sub-tile (20, 20) itself is COLLIDE_NONE, but adjacent sub-tile (20, 21) is blocked so player 20x10 box overlaps
+      const center = subTileCentre(grid, 20, 20)
+      const neighbor = subTileAt(grid, center.x + 8, center.y + 4)
+      setSubTileMask(grid, neighbor.subX, neighbor.subY, COLLIDE_WALL)
+
+      expect(terrain.overlap(center.x, center.y)).toBeGreaterThan(0)
+      expect(isTerrainPointBlocked(center.x, center.y, terrain)).toBe(true)
+      const drop = findIsometricDropPosition(center.x, center.y, [], terrain)
+      expect(terrain.overlap(drop.x, drop.y)).toBe(0)
+    })
+  })
+
+  describe('5. End-to-End GameEngine Walk & Pickup Reachability Verification', () => {
+    it('guarantees player can physically walk to and pick up items/gold dropped when monster dies inside a wall', () => {
+      const grid = createSubTileGrid(12, 12)
+      // Create a solid wall on the right half of the map (subX >= 25)
+      for (let sy = 0; sy < 60; sy += 1) {
+        for (let sx = 25; sx < 60; sx += 1) {
+          setSubTileMask(grid, sx, sy, COLLIDE_WALL)
+        }
+      }
+
+      const terrain = createIsoTerrain(grid, 1600, 1600, { width: 20, height: 10 })
+      const playerSpawn = subTileCentre(grid, 20, 25)
+      expect(terrain.overlap(playerSpawn.x, playerSpawn.y)).toBe(0)
+
+      const engine = new GameEngine(terrain, {
+        spawn: playerSpawn,
+        stats: [],
+        xpTable: [0, 500, 1500],
+        skills: [],
+        npcDefs: [],
+        questDefs: [],
+        combatOptions: {
+          playerSpeed: 4,
+          playerReach: 50,
+          playerCooldownTicks: 10,
+          playerDamage: 5,
+          playerManaPerAttack: 1,
+          respawnTicks: 100,
+        },
+        talkRadius: 50,
+        pickupRadius: 30,
+        inventoryCols: 10,
+        inventoryRows: 4,
+      })
+
+      // Drop item and gold at a point deep inside the wall (subX = 30, subY = 25)
+      const insideWallPos = subTileCentre(grid, 30, 25)
+      expect(terrain.overlap(insideWallPos.x, insideWallPos.y)).toBeGreaterThan(0)
+
+      const itemEntity = engine.dropItem(
+        { code: 'ssd', name: 'Short Sword', invWidth: 1, invHeight: 3 } as any,
+        insideWallPos.x,
+        insideWallPos.y,
+      )
+      const goldEntity = engine.dropGold(250, insideWallPos.x, insideWallPos.y)!
+
+      expect(terrain.overlap(itemEntity.x, itemEntity.y)).toBe(0)
+      expect(terrain.overlap(goldEntity.x, goldEntity.y)).toBe(0)
+
+      // Physically walk the player toward the dropped item using axis-separated collision checks
+      for (let step = 0; step < 120; step += 1) {
+        const dx = itemEntity.x - engine.world.player.x
+        const dy = itemEntity.y - engine.world.player.y
+        const dist = Math.hypot(dx, dy)
+        if (dist <= 4) break
+        const vx = (dx / dist) * 4
+        const vy = (dy / dist) * 4
+        const cur = terrain.overlap(engine.world.player.x, engine.world.player.y)
+        if (terrain.overlap(engine.world.player.x + vx, engine.world.player.y) <= cur) {
+          engine.world.player.x += vx
+        }
+        if (terrain.overlap(engine.world.player.x, engine.world.player.y + vy) <= cur) {
+          engine.world.player.y += vy
+        }
+      }
+
+      expect(
+        isWithinPickupBounds(
+          engine.world.player.x,
+          engine.world.player.y,
+          itemEntity.x,
+          itemEntity.y,
+        ),
+      ).toBe(true)
+
+      const itemPickup = engine.pickupItem(itemEntity.id)
+      expect(itemPickup.success).toBe(true)
+      const goldPickup = engine.pickupGold(goldEntity.id)
+      expect(goldPickup.success).toBe(true)
+      expect(goldPickup.amount).toBe(250)
+    })
+  })
+})

tests/monster-drop-e2e.test.ts

@@ -35,6 +35,8 @@ import { itemToUiInventoryItem } from '../src/ui/item-bridge.ts'
 import {
   InventoryPanel,
   resolveItemSpriteRect,
+  identifyUiItem,
+  isUiItemUnidentified,
   PLAYER_GOLD_CAP,
   type UiInventoryItem,
   type EquipSlotId,
@@ -575,6 +577,14 @@ describe('Milestone M11.5 (Issue #408) — Monster Drop End-to-End Integration S
       expect(invPanel.equipped[invalidSlot]).toBeUndefined()
       expect(invPanel.cursorItem).toBe(placed!.item)
 
+      // Unidentified magic/rare/set/unique drops cannot be equipped until identified (D2 1.13c)
+      if (isUiItemUnidentified(placed!.item)) {
+        const unidEquip = invPanel.clickEquipSlot(equippableSlot!)
+        expect(unidEquip).toBe(false)
+        expect(invPanel.equipped[equippableSlot!]).toBeUndefined()
+        identifyUiItem(placed!.item)
+      }
+
       // Equip into valid matching slot
       const validEquip = invPanel.clickEquipSlot(equippableSlot!)
       expect(validEquip).toBe(true)

tests/skill-tree-panel.test.ts

@@ -1,11 +1,16 @@
 import { describe, it, expect, vi } from 'vitest'
 import { existsSync, readFileSync } from 'node:fs'
 import { join } from 'node:path'
-import { SkillTreePanel, SKILL_PANEL_ORIGIN } from '../src/ui/skill-tree-panel.ts'
+import {
+  SkillTreePanel,
+  SKILL_PANEL_ORIGIN,
+  SKILL_CLOSE_BTN_BOUNDS,
+  SKILL_CLOSE_BTN_OFFSET_X,
+} from '../src/ui/skill-tree-panel.ts'
 import { BAKED_UI_MANIFEST } from '../src/ui/baked-ui-meta.ts'
 import type { D2FontRenderer } from '../src/ui/font.ts'
 
-describe('Issue #377: Authentic D2 v1.13c Skill Tree Tabs & Skill Points Banner', () => {
+describe('Authentic D2 v1.13c Skill Tree Panel Layout & Alignment', () => {
   it('manifest contains skillTabs and skillPoints image references', () => {
     expect(BAKED_UI_MANIFEST.images.skillTabs).toBe('/ui/skill-tree-tabs.png')
     expect(BAKED_UI_MANIFEST.images.skillPoints).toBe('/ui/skillpoints.png')
@@ -27,15 +32,6 @@ describe('Issue #377: Authentic D2 v1.13c Skill Tree Tabs & Skill Points Banner'
     expect(height).toBe(432)
   })
 
-  it('skillpoints.png has authentic 135x23 dimensions', () => {
-    const spPath = join(process.cwd(), 'public', 'ui', 'skillpoints.png')
-    const buf = readFileSync(spPath)
-    const width = buf.readUInt32BE(16)
-    const height = buf.readUInt32BE(20)
-    expect(width).toBe(135)
-    expect(height).toBe(23)
-  })
-
   it('draws authentic 64x432 tab column slice according to activeTab', () => {
     const panel = new SkillTreePanel()
     panel.visible = true
@@ -135,10 +131,10 @@ describe('Issue #377: Authentic D2 v1.13c Skill Tree Tabs & Skill Points Banner'
     )
   })
 
-  it('draws authentic skillpoints.png banner when unspentSkillPoints > 0', () => {
+  it('aligns top-right remaining skill points inside built-in DC6 recessed box and omits redundant bottom skillpoints banner', () => {
     const panel = new SkillTreePanel()
     panel.visible = true
-    panel.unspentSkillPoints = 5
+    panel.unspentSkillPoints = 12
 
     const mockCtx = {
       save: vi.fn(),
@@ -157,6 +153,12 @@ describe('Issue #377: Authentic D2 v1.13c Skill Tree Tabs & Skill Points Banner'
       measureText: vi.fn(() => 50),
     } as unknown as D2FontRenderer
 
+    const mockTabsImg = {
+      complete: true,
+      naturalWidth: 192,
+      naturalHeight: 432,
+    } as unknown as HTMLImageElement
+
     const mockSpImg = {
       complete: true,
       naturalWidth: 135,
@@ -167,26 +169,26 @@ describe('Issue #377: Authentic D2 v1.13c Skill Tree Tabs & Skill Points Banner'
       borderRightImg: null,
       skillPointsImg: mockSpImg,
       buySellBtnImg: null,
+      skillTabsImg: mockTabsImg,
     }, mockFont)
 
-    // Verify skillpoints banner drawn at (ox + 60, oy + 395)
-    expect(mockCtx.drawImage).toHaveBeenCalledWith(
-      mockSpImg,
-      SKILL_PANEL_ORIGIN.x + Math.round((256 - 135) / 2),
-      SKILL_PANEL_ORIGIN.y + 395,
-      135,
-      23,
+    // Top-right remaining skill points label and number aligned to recessed stone box center (ox + 276, oy + 78)
+    expect(mockFont.drawText).toHaveBeenCalledWith(
+      mockCtx,
+      '剩余技能点',
+      SKILL_PANEL_ORIGIN.x + 276,
+      SKILL_PANEL_ORIGIN.y + 38,
+      expect.objectContaining({ font: 'font8', color: 'gold', align: 'center' }),
+    )
+    expect(mockFont.drawText).toHaveBeenCalledWith(
+      mockCtx,
+      '12',
+      SKILL_PANEL_ORIGIN.x + 276,
+      SKILL_PANEL_ORIGIN.y + 78,
+      expect.objectContaining({ font: 'font16', color: 'red', align: 'center' }),
     )
 
-    // Verify when unspentSkillPoints = 0, banner is NOT drawn
-    vi.clearAllMocks()
-    panel.unspentSkillPoints = 0
-    panel.draw(mockCtx, {
-      borderRightImg: null,
-      skillPointsImg: mockSpImg,
-      buySellBtnImg: null,
-    }, mockFont)
-
+    // Redundant bottom skillpoints.png banner is NOT drawn
     expect(mockCtx.drawImage).not.toHaveBeenCalledWith(
       mockSpImg,
       expect.anything(),
@@ -195,4 +197,81 @@ describe('Issue #377: Authentic D2 v1.13c Skill Tree Tabs & Skill Points Banner'
       expect.anything(),
     )
   })
+
+  it('places and hit-tests the 32x32 Close Button inside the authentic per-tab DC6 stone socket', () => {
+    const panel = new SkillTreePanel()
+    panel.visible = true
+
+    const mockCtx = {
+      save: vi.fn(),
+      restore: vi.fn(),
+      drawImage: vi.fn(),
+      fillRect: vi.fn(),
+      strokeRect: vi.fn(),
+      fillStyle: '',
+      strokeStyle: '',
+      lineWidth: 1,
+      globalAlpha: 1,
+    } as unknown as CanvasRenderingContext2D
+
+    const mockFont = {
+      drawText: vi.fn(),
+      measureText: vi.fn(() => 50),
+    } as unknown as D2FontRenderer
+
+    const mockBuySellImg = {
+      complete: true,
+      naturalWidth: 512,
+      naturalHeight: 32,
+    } as unknown as HTMLImageElement
+
+    // Default Sorceress Cold tab (tab 2): socket at ox + 171, oy + 385
+    expect(SKILL_CLOSE_BTN_BOUNDS).toEqual({
+      x: SKILL_PANEL_ORIGIN.x + 171,
+      y: SKILL_PANEL_ORIGIN.y + 385,
+      w: 32,
+      h: 32,
+    })
+    expect(panel.getCloseButtonBounds()).toEqual(SKILL_CLOSE_BTN_BOUNDS)
+
+    panel.draw(mockCtx, {
+      borderRightImg: null,
+      skillPointsImg: null,
+      buySellBtnImg: mockBuySellImg,
+    }, mockFont)
+
+    expect(mockCtx.drawImage).toHaveBeenCalledWith(
+      mockBuySellImg,
+      10 * 32,
+      0,
+      32,
+      32,
+      SKILL_PANEL_ORIGIN.x + 171,
+      SKILL_PANEL_ORIGIN.y + 385,
+      32,
+      32,
+    )
+
+    // Switch to Sorceress Fire tab (tab 0): socket at ox + 16, oy + 385
+    panel.activeTab = 0
+    expect(panel.getCloseButtonBounds()).toEqual({
+      x: SKILL_PANEL_ORIGIN.x + 16,
+      y: SKILL_PANEL_ORIGIN.y + 385,
+      w: 32,
+      h: 32,
+    })
+
+    // Clicking inside the active tab's close button socket closes the panel
+    expect(panel.handleClick(SKILL_PANEL_ORIGIN.x + 16 + 16, SKILL_PANEL_ORIGIN.y + 385 + 16)).toBe(true)
+    expect(panel.visible).toBe(false)
+
+    // Verify all 7 classes x 3 tabs have valid authentic socket X offsets (16, 101, or 171)
+    for (const offsets of Object.values(SKILL_CLOSE_BTN_OFFSET_X)) {
+      expect(offsets).toHaveLength(3)
+      for (const ox of offsets) {
+        expect([16, 101, 171]).toContain(ox)
+      }
+    }
+  })
 })
+

tests/stash.test.ts

@@ -15,8 +15,12 @@ import {
   PLAYER_GOLD_CAP,
   STASH_DEPOSIT_BTN_BOUNDS,
   STASH_WITHDRAW_BTN_BOUNDS,
+  STASH_HEADER_ICON_SOCKET,
+  STASH_HEADER_TOP_RECESS,
+  STASH_HEADER_BOTTOM_RECESS,
   WorldPanelsHud,
 } from '../src/ui/world-panels.ts'
+import type { D2FontRenderer } from '../src/ui/font.ts'
 import {
   InventoryPanel,
   type UiInventoryItem,
@@ -604,4 +608,123 @@ describe('Milestone M5 (Issue #150): Camp Town Stash Entities Across 5 Acts & 6x
       expect(hud.inventory.visible).toBe(false)
     })
   })
+
+  describe('8. Stash Header Recessed Boxes & Text Alignment Parity (Issue #493)', () => {
+    it('defines exact TradeStash.dc6 recessed box bounds and centered baselines', () => {
+      // Left square icon socket in top row: relX = 74..93, relY = 24..38 (20x15)
+      expect(STASH_HEADER_ICON_SOCKET).toEqual({
+        x: 80 + 74,
+        y: 60 + 24,
+        relX: 74,
+        relY: 24,
+        w: 20,
+        h: 15,
+      })
+
+      // Right title recess in top row (after relX = 94..96 divider): relX = 97..247, relY = 24..38 (151x15)
+      expect(STASH_HEADER_TOP_RECESS).toEqual({
+        x: 80 + 97,
+        y: 60 + 24,
+        relX: 97,
+        relY: 24,
+        w: 151,
+        h: 15,
+        textX: 80 + 172,
+        textY: 60 + 35,
+      })
+
+      // Full-width gold readout recess in bottom row: relX = 75..246, relY = 49..65 (172x17)
+      expect(STASH_HEADER_BOTTOM_RECESS).toEqual({
+        x: 80 + 75,
+        y: 60 + 49,
+        relX: 75,
+        relY: 49,
+        w: 172,
+        h: 17,
+        textX: 80 + 160,
+        textY: 60 + 61,
+      })
+    })
+
+    it('renders Private Stash title and gold readout centered inside their respective recessed boxes without crossing dividers', () => {
+      const panels = new WorldPanelsHud()
+      panels.stashGold = 2_500_000
+
+      const drawTextCalls: Array<{
+        text: string
+        x: number
+        y: number
+        opts?: { font?: string; color?: string; align?: string }
+      }> = []
+
+      const mockFont = {
+        drawText: (_ctx: CanvasRenderingContext2D, text: string, x: number, y: number, opts?: any) => {
+          drawTextCalls.push({ text, x, y, opts })
+        },
+        measureText: (text: string) => text.length * 6.5,
+      } as unknown as D2FontRenderer
+
+      const mockCtx = {
+        drawImage: () => {},
+        fillRect: () => {},
+        strokeRect: () => {},
+        fillStyle: '',
+        strokeStyle: '',
+      } as unknown as CanvasRenderingContext2D
+
+      panels.drawLeftDockPanel(
+        mockCtx,
+        'stash',
+        {
+          questBgImg: null,
+          waypointBgImg: null,
+          borderLeftImg: null,
+          stashBgImg: null,
+          cubeBgImg: null,
+          vendorBgImg: null,
+          buySellBtnImg: null,
+        },
+        mockFont,
+      )
+
+      const titleCall = drawTextCalls.find(c => c.text.includes('私人储物箱'))
+      const goldCall = drawTextCalls.find(c => c.text.includes('储物箱金币'))
+
+      expect(titleCall).toBeDefined()
+      expect(goldCall).toBeDefined()
+
+      // 1. Top title must be centered in the right compartment (relX = 97..247 -> center ox + 172 = 252)
+      // and vertically centered in relY = 24..38 (alphabetic baseline oy + 35 = 95)
+      expect(titleCall!.x).toBe(STASH_HEADER_TOP_RECESS.textX)
+      expect(titleCall!.y).toBe(STASH_HEADER_TOP_RECESS.textY)
+      expect(titleCall!.opts?.font).toBe('font8')
+      expect(titleCall!.opts?.color).toBe('gold')
+      expect(titleCall!.opts?.align).toBe('center')
+
+      // Verify title glyph vertical span [y - 9, y + 1] stays strictly inside top recess [oy + 24, oy + 38]
+      const topRecessTop = STASH_HEADER_TOP_RECESS.y
+      const topRecessBottom = STASH_HEADER_TOP_RECESS.y + STASH_HEADER_TOP_RECESS.h - 1
+      expect(titleCall!.y - 9).toBeGreaterThanOrEqual(topRecessTop)
+      expect(titleCall!.y + 1).toBeLessThanOrEqual(topRecessBottom)
+
+      // Verify title horizontal span (~130px in font8) stays strictly inside [ox + 97, ox + 247] (never crossing relX = 94..96 divider)
+      const approxTitleWidth = 130
+      expect(titleCall!.x - approxTitleWidth / 2).toBeGreaterThan(STASH_HEADER_TOP_RECESS.x)
+      expect(titleCall!.x + approxTitleWidth / 2).toBeLessThan(STASH_HEADER_TOP_RECESS.x + STASH_HEADER_TOP_RECESS.w)
+
+      // 2. Bottom gold text must be centered in the bottom recess (relX = 75..246 -> center ox + 160 = 240)
+      // and vertically centered in relY = 49..65 (alphabetic baseline oy + 61 = 121)
+      expect(goldCall!.x).toBe(STASH_HEADER_BOTTOM_RECESS.textX)
+      expect(goldCall!.y).toBe(STASH_HEADER_BOTTOM_RECESS.textY)
+      expect(goldCall!.opts?.font).toBe('font8')
+      expect(goldCall!.opts?.color).toBe('white')
+      expect(goldCall!.opts?.align).toBe('center')
+
+      // Verify gold glyph vertical span [y - 9, y + 1] stays strictly inside bottom recess [oy + 49, oy + 65]
+      const bottomRecessTop = STASH_HEADER_BOTTOM_RECESS.y
+      const bottomRecessBottom = STASH_HEADER_BOTTOM_RECESS.y + STASH_HEADER_BOTTOM_RECESS.h - 1
+      expect(goldCall!.y - 9).toBeGreaterThanOrEqual(bottomRecessTop)
+      expect(goldCall!.y + 1).toBeLessThanOrEqual(bottomRecessBottom)
+    })
+  })
 })

tests/unidentified-drops-identify.test.ts

@@ -0,0 +1,449 @@
+import { describe, expect, it, vi } from 'vitest'
+import { D2Rng } from '../src/game/d2-rng.ts'
+import {
+  createDroppedItem,
+  shouldSpawnIdentifiedByDefault,
+} from '../src/game/drop-pipeline.ts'
+import { getEmbeddedDropTables } from '../src/game/embedded-drop-tables.ts'
+import {
+  GroundItemManager,
+  isGroundSourceUnidentified,
+  resolveGroundItemMetadata,
+} from '../src/game/ground-items.ts'
+import {
+  calculateTransactionCost,
+  TransactionType,
+} from '../src/game/item-cost.ts'
+import { ItemFlag, ItemQuality, type Item } from '../src/game/items.ts'
+import { VendorNpcId } from '../src/game/npc-table.ts'
+import {
+  generateGambleInventory,
+  generateVendorStoreItem,
+  resolveGambledItem,
+} from '../src/game/vendor-generator.ts'
+import { BAKED_UI_MANIFEST } from '../src/ui/baked-ui-meta.ts'
+import type { D2ColorCode, D2FontName, D2FontRenderer } from '../src/ui/font.ts'
+import {
+  formatGroundItemLabelText,
+  getGroundItemQualityColor,
+  GROUND_LABEL_QUALITY_COLORS,
+} from '../src/ui/ground-labels.ts'
+import {
+  EQUIP_SLOTS_LAYOUT,
+  identifyUiItem,
+  INV_GRID_ORIGIN,
+  InventoryPanel,
+  isUiItemUnidentified,
+  itemToUiInventoryItem,
+  resolveItemSpriteRect,
+  type UiInventoryItem,
+} from '../src/ui/inventory.ts'
+import { WorldPanelsHud } from '../src/ui/world-panels.ts'
+
+function createMockTooltipCanvas() {
+  const fontCalls: Array<{ text: string; color?: D2ColorCode | undefined; font?: D2FontName | undefined }> = []
+  const fillStyles: string[] = []
+  const ctx = {
+    save: vi.fn(),
+    restore: vi.fn(),
+    drawImage: vi.fn(),
+    fillRect: vi.fn(function (this: { fillStyle: string }) {
+      fillStyles.push(this.fillStyle)
+    }),
+    strokeRect: vi.fn(),
+    beginPath: vi.fn(),
+    moveTo: vi.fn(),
+    lineTo: vi.fn(),
+    stroke: vi.fn(),
+    fillText: vi.fn(),
+    fillStyle: '',
+    strokeStyle: '',
+    lineWidth: 1,
+  } as unknown as CanvasRenderingContext2D
+
+  const font = {
+    loaded: true,
+    measureText: vi.fn((text: string) => text.length * 8),
+    drawText: vi.fn(
+      (
+        _ctx: CanvasRenderingContext2D,
+        text: string,
+        _x: number,
+        _y: number,
+        opts?: { font?: D2FontName; color?: D2ColorCode },
+      ) => {
+        fontCalls.push({ text, color: opts?.color, font: opts?.font })
+      },
+    ),
+  } as unknown as D2FontRenderer
+
+  return { ctx, font, fontCalls, fillStyles }
+}
+
+describe('Diablo II v1.13c Unidentified Equipment Drops & Identification System', () => {
+  const dropTables = getEmbeddedDropTables()
+  const shakoBase = dropTables.getBase('uap')!
+  const harlequinDef = dropTables.uniques.getEnabledByCode('uap')[0]!
+
+  function makeDroppedShako(qualityTier: 'normal' | 'magic' | 'rare' | 'unique', seed = 101): Item {
+    const rng = new D2Rng(seed)
+    return createDroppedItem(shakoBase, qualityTier, {
+      uniqueItem: qualityTier === 'unique' ? harlequinDef : undefined,
+      itemTypes: dropTables.itemTypes,
+      ilvl: 85,
+      dwInitSeed: seed,
+      itemRng: rng,
+    })
+  }
+
+  describe('1. Drop Pipeline Unidentified Spawn Rules (D2Game.dll / Items.cpp)', () => {
+    it('spawns low, normal, superior, and quest items as identified, and magic/rare/set/unique/crafted items as unidentified', () => {
+      expect(shakoBase).toBeDefined()
+      expect(harlequinDef).toBeDefined()
+
+      expect(shouldSpawnIdentifiedByDefault(shakoBase, 'low')).toBe(true)
+      expect(shouldSpawnIdentifiedByDefault(shakoBase, 'normal')).toBe(true)
+      expect(shouldSpawnIdentifiedByDefault(shakoBase, 'superior')).toBe(true)
+      expect(shouldSpawnIdentifiedByDefault(shakoBase, 'magic')).toBe(false)
+      expect(shouldSpawnIdentifiedByDefault(shakoBase, 'rare')).toBe(false)
+      expect(shouldSpawnIdentifiedByDefault(shakoBase, 'set')).toBe(false)
+      expect(shouldSpawnIdentifiedByDefault(shakoBase, 'unique')).toBe(false)
+      expect(shouldSpawnIdentifiedByDefault(shakoBase, 'crafted' as any)).toBe(false)
+
+      // Quest items (base.quest > 0) always spawn identified regardless of quality tier
+      const cubeBase = dropTables.getBase('box')!
+      expect(cubeBase.quest).toBeGreaterThan(0)
+      expect(shouldSpawnIdentifiedByDefault(cubeBase, 'unique')).toBe(true)
+
+      // Verify concrete createDroppedItem outputs
+      const normalItem = makeDroppedShako('normal', 1)
+      expect(normalItem.identified).toBe(true)
+      expect(normalItem.flags?.identified).toBe(true)
+      expect((normalItem.rawFlags! & ItemFlag.IDENTIFIED) !== 0).toBe(true)
+
+      const magicItem = makeDroppedShako('magic', 2)
+      expect(magicItem.identified).toBe(false)
+      expect(magicItem.flags?.identified).toBe(false)
+      expect((magicItem.rawFlags! & ItemFlag.IDENTIFIED) !== 0).toBe(false)
+
+      const rareItem = makeDroppedShako('rare', 3)
+      expect(rareItem.identified).toBe(false)
+      expect(rareItem.flags?.identified).toBe(false)
+      expect((rareItem.rawFlags! & ItemFlag.IDENTIFIED) !== 0).toBe(false)
+
+      const uniqueShako = makeDroppedShako('unique', 4)
+      expect(uniqueShako.quality).toBe(ItemQuality.UNIQUE)
+      expect(uniqueShako.name).toBe('Harlequin Crest')
+      expect(uniqueShako.identified).toBe(false)
+      expect(uniqueShako.flags?.identified).toBe(false)
+      expect((uniqueShako.rawFlags! & ItemFlag.IDENTIFIED) !== 0).toBe(false)
+    })
+  })
+
+  describe('2. Vendor Store, Gambling Reveal & Unidentified Transaction Cost', () => {
+    it('spawns vendor trade items and resolved gamble items as pre-identified', () => {
+      const rng = new D2Rng(42)
+      const capBase = dropTables.getBase('cap')!
+      const vendorMagic = generateVendorStoreItem({
+        base: capBase,
+        vendorId: VendorNpcId.CHARSI,
+        qualityTier: 'magic',
+        cLvl: 25,
+        nItemLevel: 30,
+        difficulty: 0,
+        permStore: false,
+        tables: dropTables,
+        rng,
+      })
+      expect(vendorMagic).not.toBeNull()
+      expect(vendorMagic!.identified).toBe(true)
+      expect(vendorMagic!.flags?.identified).toBe(true)
+      expect((vendorMagic!.rawFlags! & ItemFlag.IDENTIFIED) !== 0).toBe(true)
+
+      const gambleGrid = generateGambleInventory({
+        vendorId: VendorNpcId.GHEED,
+        cLvl: 30,
+        tables: dropTables,
+        rng,
+      })
+      const mystery = gambleGrid.list()[0]!.item
+      expect(mystery.isGambleMystery).toBe(true)
+      expect(mystery.identified).toBe(false)
+
+      const gambled = resolveGambledItem({
+        mysteryItem: mystery,
+        cLvl: 30,
+        tables: dropTables,
+        rng,
+      })
+      expect(gambled.identified).toBe(true)
+      expect(gambled.flags?.identified).toBe(true)
+      expect(gambled.isGambleMystery).toBe(false)
+    })
+
+    it('discounts sell price of unidentified magic/unique items until identified (0x6FD9B1C0)', () => {
+      const uniqueShako = makeDroppedShako('unique', 7)
+      expect(uniqueShako.identified).toBe(false)
+
+      const unidSellCost = calculateTransactionCost({
+        item: uniqueShako,
+        transactionType: TransactionType.SELL,
+        vendorId: VendorNpcId.CHARSI,
+        difficulty: 2,
+        tables: dropTables,
+      })
+      const idShako: Item = {
+        ...uniqueShako,
+        identified: true,
+        flags: { ...uniqueShako.flags!, identified: true },
+        rawFlags: uniqueShako.rawFlags! | ItemFlag.IDENTIFIED,
+      }
+      const idSellCost = calculateTransactionCost({
+        item: idShako,
+        transactionType: TransactionType.SELL,
+        vendorId: VendorNpcId.CHARSI,
+        difficulty: 2,
+        tables: dropTables,
+      })
+
+      expect(unidSellCost).toBeGreaterThan(0)
+      expect(idSellCost).toBeGreaterThan(unidSellCost)
+    })
+  })
+
+  describe('3. Ground Item Metadata & Alt Label Masking', () => {
+    it('masks unidentified ground item labels to base item name while preserving quality color and underlying secret name', () => {
+      const uniqueShako = makeDroppedShako('unique', 11)
+      expect(isGroundSourceUnidentified(uniqueShako)).toBe(true)
+
+      const meta = resolveGroundItemMetadata(uniqueShako)
+      expect(meta.quality).toBe('unique')
+      expect(meta.name).toBe('Shako')
+      expect(meta.nameZh).toContain('军帽')
+      expect(meta.nameZh).not.toContain('Harlequin Crest')
+      expect(meta.nameZh).not.toContain('谐角之冠')
+
+      const manager = new GroundItemManager()
+      const groundEntity = manager.add(uniqueShako, 10, 10, 320, 240)
+      expect(getGroundItemQualityColor(groundEntity)).toBe(GROUND_LABEL_QUALITY_COLORS.unique)
+
+      const labelText = formatGroundItemLabelText(groundEntity)
+      expect(labelText).toContain('军帽')
+      expect(labelText).not.toContain('Harlequin Crest')
+      expect(labelText).not.toContain('谐角之冠')
+
+      // Underlying item's secret identity is untouched so picking it up and identifying it works
+      expect(uniqueShako.name).toBe('Harlequin Crest')
+    })
+  })
+
+  describe('4. UI Item Bridge, Sprite/Dye Masking, Tooltip Masking & Equipping Gate', () => {
+    it('masks unique dye transform and custom unique invFile while unidentified and restores them upon identification', () => {
+      const uniqueShako = makeDroppedShako('unique', 19)
+      const uiShako = itemToUiInventoryItem(uniqueShako, dropTables)
+
+      expect(isUiItemUnidentified(uiShako)).toBe(true)
+      expect(uiShako.invtransform).toBeTruthy()
+      expect(uiShako.baseInvFile).toBe('invcap')
+
+      const unidSprite = resolveItemSpriteRect(uiShako)
+      const baseCapSprite = BAKED_UI_MANIFEST.itemRects['invcap']
+      const dyedCapSprite = BAKED_UI_MANIFEST.itemRects[`invcap_${uiShako.invtransform}`]
+      expect(unidSprite).toEqual(baseCapSprite)
+      if (dyedCapSprite) {
+        expect(unidSprite).not.toEqual(dyedCapSprite)
+      }
+
+      // Identify and verify dyed sprite is now resolved
+      identifyUiItem(uiShako)
+      expect(isUiItemUnidentified(uiShako)).toBe(false)
+      if (dyedCapSprite) {
+        expect(resolveItemSpriteRect(uiShako)).toEqual(dyedCapSprite)
+      }
+    })
+
+    it('renders red cell backdrop in InventoryPanel.draw and hides secret name/affixes in drawItemTooltip while unidentified', () => {
+      const uniqueShako = makeDroppedShako('unique', 23)
+      const uiShako = itemToUiInventoryItem(uniqueShako, dropTables)
+
+      const inv = new InventoryPanel()
+      inv.visible = true
+      inv.gridItems = [{ item: uiShako, col: 0, row: 0 }]
+
+      const { ctx, font, fontCalls, fillStyles } = createMockTooltipCanvas()
+      inv.draw(
+        ctx,
+        {
+          borderRightImg: null,
+          invSheetImg: null,
+          invTab0Img: null,
+          invTab1Img: null,
+          buySellBtnImg: null,
+          itemsAtlasImg: null,
+          itemRects: BAKED_UI_MANIFEST.itemRects,
+        },
+        font,
+      )
+      expect(fillStyles).toContain('rgba(72, 18, 18, 0.50)')
+
+      // Hover tooltip while unidentified
+      const wp = new WorldPanelsHud()
+      fontCalls.length = 0
+      wp.drawItemTooltip(ctx, { item: uiShako, x: 450, y: 300 }, font, false)
+
+      const texts = fontCalls.map(c => c.text)
+      expect(texts[0]).toContain('军帽')
+      expect(texts.some(t => t.includes('Harlequin Crest') || t.includes('谐角之冠'))).toBe(false)
+      expect(texts).toContain('未辨识 (Unidentified)')
+      expect(texts).toContain('无法使用 (Cannot be Equipped)')
+
+      // Hover tooltip after identification
+      identifyUiItem(uiShako)
+      fontCalls.length = 0
+      wp.drawItemTooltip(ctx, { item: uiShako, x: 450, y: 300 }, font, false)
+      const identifiedTexts = fontCalls.map(c => c.text)
+      expect(identifiedTexts[0]).toContain('Harlequin Crest')
+      expect(identifiedTexts).not.toContain('未辨识 (Unidentified)')
+      expect(identifiedTexts).not.toContain('无法使用 (Cannot be Equipped)')
+      expect(identifiedTexts.length).toBeGreaterThan(texts.length)
+    })
+  })
+
+  describe('5. End-to-End Identification Flows: Scroll (isc), Tome (ibk), and Deckard Cain', () => {
+    it('identifies an item using a Scroll of Identify (isc), consumes the scroll, and unlocks equipping', () => {
+      const inv = new InventoryPanel()
+      inv.visible = true
+      delete inv.equipped.helm
+
+      const uniqueShako = itemToUiInventoryItem(makeDroppedShako('unique', 31), dropTables)
+      const iscBase = dropTables.getBase('isc')!
+      const scrollItem = itemToUiInventoryItem(
+        createDroppedItem(iscBase, 'normal', {
+          itemTypes: dropTables.itemTypes,
+          ilvl: 1,
+          dwInitSeed: 32,
+          itemRng: new D2Rng(32),
+        }),
+        dropTables,
+      )
+
+      inv.gridItems = [
+        { item: uniqueShako, col: 0, row: 0 },
+        { item: scrollItem, col: 2, row: 0 },
+      ]
+
+      // Right-click Scroll of Identify at (2, 0) via handleClick(button=2) to enter Identify Cursor Mode
+      const scrollX = INV_GRID_ORIGIN.x + 2 * INV_GRID_ORIGIN.cellPx + 5
+      const scrollY = INV_GRID_ORIGIN.y + 5
+      expect(inv.handleClick(scrollX, scrollY, undefined, 2)).toBe(true)
+      expect(inv.isIdentifyMode()).toBe(true)
+
+      // Left-click the unidentified Shako at (0, 0) via handleClick(button=0) to identify it
+      const shakoX = INV_GRID_ORIGIN.x + 5
+      const shakoY = INV_GRID_ORIGIN.y + 5
+      expect(inv.handleClick(shakoX, shakoY, undefined, 0)).toBe(true)
+      expect(inv.isIdentifyMode()).toBe(false)
+      expect(isUiItemUnidentified(uniqueShako)).toBe(false)
+      expect((uniqueShako.rawItem!.rawFlags! & ItemFlag.IDENTIFIED) !== 0).toBe(true)
+
+      // Scroll was consumed and removed from inventory
+      expect(inv.gridItems.some(p => p.item.id === scrollItem.id)).toBe(false)
+
+      // Now pick up the identified Shako and equip it into the helm slot
+      expect(inv.clickGridCell(0, 0)).toBe(true)
+      expect(inv.cursorItem?.id).toBe(uniqueShako.id)
+      expect(inv.clickEquipSlot('helm')).toBe(true)
+      expect((inv.equipped.helm as UiInventoryItem | undefined)?.id).toBe(uniqueShako.id)
+      expect(inv.cursorItem).toBeNull()
+    })
+
+    it('identifies an item using a Tome of Identify (ibk) and decrements tome quantity', () => {
+      const inv = new InventoryPanel()
+      inv.visible = true
+      const rinBase = dropTables.getBase('rin')!
+      const ibkBase = dropTables.getBase('ibk')!
+
+      const rareRing = itemToUiInventoryItem(
+        createDroppedItem(rinBase, 'rare', {
+          itemTypes: dropTables.itemTypes,
+          ilvl: 60,
+          dwInitSeed: 41,
+          itemRng: new D2Rng(41),
+        }),
+        dropTables,
+      )
+      const tomeItem = itemToUiInventoryItem(
+        {
+          ...createDroppedItem(ibkBase, 'normal', {
+            itemTypes: dropTables.itemTypes,
+            ilvl: 1,
+            dwInitSeed: 42,
+            itemRng: new D2Rng(42),
+          }),
+          quantity: 5,
+          stack: 5,
+        },
+        dropTables,
+      )
+
+      inv.gridItems = [
+        { item: rareRing, col: 0, row: 0 },
+        { item: tomeItem, col: 1, row: 0 },
+      ]
+
+      const tomeX = INV_GRID_ORIGIN.x + 1 * INV_GRID_ORIGIN.cellPx + 5
+      const tomeY = INV_GRID_ORIGIN.y + 5
+      expect(inv.handleClick(tomeX, tomeY, undefined, 2)).toBe(true)
+      expect(inv.isIdentifyMode()).toBe(true)
+
+      const ringX = INV_GRID_ORIGIN.x + 5
+      const ringY = INV_GRID_ORIGIN.y + 5
+      expect(inv.handleClick(ringX, ringY, undefined, 0)).toBe(true)
+      expect(isUiItemUnidentified(rareRing)).toBe(false)
+      expect(tomeItem.quantity).toBe(4)
+      expect(inv.gridItems.some(p => p.item.id === tomeItem.id)).toBe(true)
+    })
+
+    it('identifies all unidentified items across Inventory, Stash, and Horadric Cube via Deckard Cain', () => {
+      const inv = new InventoryPanel()
+      const wp = new WorldPanelsHud()
+      const rinBase = dropTables.getBase('rin')!
+      const amuBase = dropTables.getBase('amu')!
+
+      const bagUnid = itemToUiInventoryItem(makeDroppedShako('unique', 51), dropTables)
+      const stashUnid = itemToUiInventoryItem(
+        createDroppedItem(rinBase, 'rare', {
+          itemTypes: dropTables.itemTypes,
+          ilvl: 60,
+          dwInitSeed: 52,
+          itemRng: new D2Rng(52),
+        }),
+        dropTables,
+      )
+      const cubeUnid = itemToUiInventoryItem(
+        createDroppedItem(amuBase, 'magic', {
+          itemTypes: dropTables.itemTypes,
+          ilvl: 50,
+          dwInitSeed: 53,
+          itemRng: new D2Rng(53),
+        }),
+        dropTables,
+      )
+
+      inv.gridItems = [{ item: bagUnid, col: 0, row: 0 }]
+      wp.stashItems = [{ item: stashUnid, col: 0, row: 0 }]
+      wp.cubeItems = [{ item: cubeUnid, col: 0, row: 0 }]
+
+      expect(isUiItemUnidentified(bagUnid)).toBe(true)
+      expect(isUiItemUnidentified(stashUnid)).toBe(true)
+      expect(isUiItemUnidentified(cubeUnid)).toBe(true)
+
+      const count = wp.identifyAllUiItems(inv)
+      expect(count).toBe(3)
+      expect(isUiItemUnidentified(bagUnid)).toBe(false)
+      expect(isUiItemUnidentified(stashUnid)).toBe(false)
+      expect(isUiItemUnidentified(cubeUnid)).toBe(false)
+      expect(wp.identifyAllUiItems(inv)).toBe(0)
+    })
+  })
+})

tests/vendor-panel-ui.test.ts

@@ -10,7 +10,11 @@ import { MpqArchive } from '../src/mpq/archive.ts'
 import { fileSource } from '../src/mpq/file-source.ts'
 import { MountedArchives } from '../src/mpq/mount.ts'
 import { BAKED_UI_MANIFEST } from '../src/ui/baked-ui-meta.ts'
+<<<<<<< HEAD
+import type { D2ColorCode, D2FontName as FontSizeName, D2FontRenderer } from '../src/ui/font.ts'
+=======
 import type { D2ColorCode, D2FontRenderer, D2FontName } from '../src/ui/font.ts'
+>>>>>>> ce00574 (fix(ui): restore authentic D2 v1.13c NPC dialog popup menu (Fixes #489))
 import { InventoryPanel, type UiInventoryItem } from '../src/ui/inventory.ts'
 import {
   BLACKSMITH_CLASS_IDS,
@@ -454,7 +458,7 @@ describe('Diablo II 1.13c Vendor / BuySell Panel UI Parity', () => {
     expect(wp.activeVendorTab).toBe('armor')
 
     // Leave only 1 non-permStore item on the armor tab and buy it
-    const nonPerm = wp.vendorTabPlacements.armor.find(p => !p.item.rawItem?.permStore)
+    const nonPerm = wp.vendorTabPlacements.armor.find(p => !p.item.permStore && !p.item.rawItem?.permStore)
     expect(nonPerm).toBeDefined()
     wp.vendorTabPlacements.armor = [nonPerm!]