diff --git a/src/AcDream.Core/Items/ClientObject.cs b/src/AcDream.Core/Items/ClientObject.cs
index 2ec5d309..cc3695b6 100644
--- a/src/AcDream.Core/Items/ClientObject.cs
+++ b/src/AcDream.Core/Items/ClientObject.cs
@@ -57,46 +57,46 @@ public enum ItemType : uint
 }
 
 /// <summary>
-/// Equipment slot bitmask. 31 slots from head to Aetheria. Paperdoll
-/// widget offsets <c>+0x604..+0x660</c> in the retail panel correspond
-/// to these bits 1:1 (see r06 §2 and UI slice 05 paperdoll section).
+/// Equipment slot bitmask — the verbatim retail <c>INVENTORY_LOC</c> enum
+/// (docs/research/named-retail/acclient.h:3193; identical to ACE's EquipMask).
+/// The wire (ValidLocations / CurrentWieldedLocation / WieldObject EquipLoc) delivers
+/// these exact bits. Pinned by EquipMaskTests — do NOT renumber.
 /// </summary>
 [Flags]
 public enum EquipMask : uint
 {
-    None          = 0,
-    HeadWear      = 0x00000001,
-    ChestWear     = 0x00000002,
-    AbdomenWear   = 0x00000004,
-    UpperArmWear  = 0x00000008,
-    LowerArmWear  = 0x00000010,
-    HandWear      = 0x00000020,
-    UpperLegWear  = 0x00000040,
-    LowerLegWear  = 0x00000080,
-    FootWear      = 0x00000100,
-    ChestArmor    = 0x00000200,
-    AbdomenArmor  = 0x00000400,
-    UpperArmArmor = 0x00000800,
-    LowerArmArmor = 0x00001000,
-    HandArmor     = 0x00002000,
-    UpperLegArmor = 0x00004000,
-    LowerLegArmor = 0x00008000,
-    FootArmor     = 0x00010000,
-    Necklace      = 0x00020000,
-    LeftBracelet  = 0x00040000,
-    RightBracelet = 0x00080000,
-    LeftRing      = 0x00100000,
-    RightRing     = 0x00200000,
-    MeleeWeapon   = 0x00400000,
-    Shield        = 0x00800000,
-    MissileWeapon = 0x01000000,
-    Held          = 0x02000000,       // lit torch, book in hand
-    MissileAmmo   = 0x04000000,
-    Cloak         = 0x08000000,
-    TrinketOne    = 0x10000000,
-    AetheriaRed   = 0x20000000,
-    AetheriaYellow= 0x40000000,
-    AetheriaBlue  = 0x80000000u,
+    None           = 0x00000000,
+    HeadWear       = 0x00000001,
+    ChestWear      = 0x00000002,
+    AbdomenWear    = 0x00000004,
+    UpperArmWear   = 0x00000008,
+    LowerArmWear   = 0x00000010,
+    HandWear       = 0x00000020,
+    UpperLegWear   = 0x00000040,
+    LowerLegWear   = 0x00000080,
+    FootWear       = 0x00000100,
+    ChestArmor     = 0x00000200,
+    AbdomenArmor   = 0x00000400,
+    UpperArmArmor  = 0x00000800,
+    LowerArmArmor  = 0x00001000,
+    UpperLegArmor  = 0x00002000,
+    LowerLegArmor  = 0x00004000,
+    NeckWear       = 0x00008000,
+    WristWearLeft  = 0x00010000,
+    WristWearRight = 0x00020000,
+    FingerWearLeft = 0x00040000,
+    FingerWearRight= 0x00080000,
+    MeleeWeapon    = 0x00100000,
+    Shield         = 0x00200000,
+    MissileWeapon  = 0x00400000,
+    MissileAmmo    = 0x00800000,
+    Held           = 0x01000000,
+    TwoHanded      = 0x02000000,
+    TrinketOne     = 0x04000000,
+    Cloak          = 0x08000000,
+    SigilOne       = 0x10000000,
+    SigilTwo       = 0x20000000,
+    SigilThree     = 0x40000000,
 }
 
 /// <summary>
diff --git a/tests/AcDream.Core.Tests/Items/EquipMaskTests.cs b/tests/AcDream.Core.Tests/Items/EquipMaskTests.cs
new file mode 100644
index 00000000..d3576603
--- /dev/null
+++ b/tests/AcDream.Core.Tests/Items/EquipMaskTests.cs
@@ -0,0 +1,54 @@
+using AcDream.Core.Items;
+using Xunit;
+
+namespace AcDream.Core.Tests.Items;
+
+/// <summary>
+/// Pins every EquipMask member to the verbatim retail INVENTORY_LOC value
+/// (docs/research/named-retail/acclient.h:3193). The wire delivers these exact bits
+/// (ACE EquipMask == retail INVENTORY_LOC); any drift desyncs the paperdoll element-id→mask
+/// map and the GetAndWieldItem wire. This test is the anti-regression lock.
+/// </summary>
+public sealed class EquipMaskTests
+{
+    [Theory]
+    [InlineData(0x00000000u, EquipMask.None)]
+    [InlineData(0x00000001u, EquipMask.HeadWear)]
+    [InlineData(0x00000002u, EquipMask.ChestWear)]
+    [InlineData(0x00000004u, EquipMask.AbdomenWear)]
+    [InlineData(0x00000008u, EquipMask.UpperArmWear)]
+    [InlineData(0x00000010u, EquipMask.LowerArmWear)]
+    [InlineData(0x00000020u, EquipMask.HandWear)]
+    [InlineData(0x00000040u, EquipMask.UpperLegWear)]
+    [InlineData(0x00000080u, EquipMask.LowerLegWear)]
+    [InlineData(0x00000100u, EquipMask.FootWear)]
+    [InlineData(0x00000200u, EquipMask.ChestArmor)]
+    [InlineData(0x00000400u, EquipMask.AbdomenArmor)]
+    [InlineData(0x00000800u, EquipMask.UpperArmArmor)]
+    [InlineData(0x00001000u, EquipMask.LowerArmArmor)]
+    [InlineData(0x00002000u, EquipMask.UpperLegArmor)]
+    [InlineData(0x00004000u, EquipMask.LowerLegArmor)]
+    [InlineData(0x00008000u, EquipMask.NeckWear)]
+    [InlineData(0x00010000u, EquipMask.WristWearLeft)]
+    [InlineData(0x00020000u, EquipMask.WristWearRight)]
+    [InlineData(0x00040000u, EquipMask.FingerWearLeft)]
+    [InlineData(0x00080000u, EquipMask.FingerWearRight)]
+    [InlineData(0x00100000u, EquipMask.MeleeWeapon)]
+    [InlineData(0x00200000u, EquipMask.Shield)]
+    [InlineData(0x00400000u, EquipMask.MissileWeapon)]
+    [InlineData(0x00800000u, EquipMask.MissileAmmo)]
+    [InlineData(0x01000000u, EquipMask.Held)]
+    [InlineData(0x02000000u, EquipMask.TwoHanded)]
+    [InlineData(0x04000000u, EquipMask.TrinketOne)]
+    [InlineData(0x08000000u, EquipMask.Cloak)]
+    [InlineData(0x10000000u, EquipMask.SigilOne)]
+    [InlineData(0x20000000u, EquipMask.SigilTwo)]
+    [InlineData(0x40000000u, EquipMask.SigilThree)]
+    public void Member_has_canonical_retail_value(uint expected, EquipMask member)
+        => Assert.Equal(expected, (uint)member);
+
+    [Fact]
+    public void Weapon_ready_slot_composite_is_0x3500000() // acclient.h:3235 WEAPON_READY_SLOT_LOC
+        => Assert.Equal(0x3500000u,
+            (uint)(EquipMask.MeleeWeapon | EquipMask.MissileWeapon | EquipMask.Held | EquipMask.TwoHanded));
+}