diff --git a/Assets/_Project/Scripts/Gameplay/BuilderUpgradeManager.cs b/Assets/_Project/Scripts/Gameplay/BuilderUpgradeManager.cs
index 0013ef9..5f07d31 100644
--- a/Assets/_Project/Scripts/Gameplay/BuilderUpgradeManager.cs
+++ b/Assets/_Project/Scripts/Gameplay/BuilderUpgradeManager.cs
@@ -13,10 +13,12 @@ namespace TD.Gameplay
     /// <see cref="PlayerBuffManager"/>.
     /// </summary>
     /// <remarks>
-    /// <para><b>Bitmask, not a list.</b> A builder effect carries no per-grant state (no level,
-    /// no enable/disable toggle) — it's either granted or it isn't — so the granted set is one
-    /// <see cref="NetworkVariable{T}"/> bitmask keyed by <see cref="BuilderEffectKind"/> rather
-    /// than a <c>NetworkList</c>. "Has effect" and "grant effect" are both O(1) bit ops.</para>
+    /// <para><b>List of granted kinds.</b> A builder effect carries no per-grant state (no
+    /// level, no enable/disable toggle) — it's either granted or it isn't — so the granted set
+    /// is a <see cref="NetworkList{T}"/> of <see cref="BuilderEffectKind"/> values. Stored as
+    /// <c>byte</c> because <c>NetworkList&lt;T&gt;</c> requires <c>T : IEquatable&lt;T&gt;</c>
+    /// and plain enums don't implement that (see <see cref="TD.Gameplay.BuildJob"/> for the
+    /// same constraint on a struct); <c>byte</c> already does, for free.</para>
     ///
     /// <para><b>Granted via draft.</b> <see cref="TD.Gameplay.Draft.BuilderEffectDraftOption"/>
     /// calls <see cref="ServerGrantEffect"/> when a player picks it. Effects are permanent for
@@ -60,13 +62,10 @@ namespace TD.Gameplay
 
         // ----- Networked state --------------------------------------------
 
-        // One bit per BuilderEffectKind. readPerm Everyone (consistent with the other
-        // per-player managers); writePerm Server.
-        private readonly NetworkVariable<uint> grantedMask = new NetworkVariable<uint>(
-            value: 0,
-            readPerm: NetworkVariableReadPermission.Everyone,
-            writePerm: NetworkVariableWritePermission.Server
-        );
+        // Granted effect kinds, stored as byte (see class remarks for why not the enum
+        // directly). readPerm Everyone (consistent with the other per-player managers);
+        // writePerm Server — both are NetworkList's defaults.
+        private readonly NetworkList<byte> grantedKinds = new NetworkList<byte>();
 
         /// <summary>Fired on every peer when a new effect is granted.</summary>
         public event System.Action OnUpgradesChanged;
@@ -76,23 +75,23 @@ namespace TD.Gameplay
         public override void OnNetworkSpawn()
         {
             s_byClientId[OwnerClientId] = this;
-            grantedMask.OnValueChanged += HandleMaskChanged;
+            grantedKinds.OnListChanged += HandleGrantedKindsChanged;
         }
 
         public override void OnNetworkDespawn()
         {
-            grantedMask.OnValueChanged -= HandleMaskChanged;
+            grantedKinds.OnListChanged -= HandleGrantedKindsChanged;
 
             if (s_byClientId.TryGetValue(OwnerClientId, out var registered) && registered == this)
                 s_byClientId.Remove(OwnerClientId);
         }
 
-        private void HandleMaskChanged(uint previous, uint current) => OnUpgradesChanged?.Invoke();
+        private void HandleGrantedKindsChanged(NetworkListEvent<byte> change) => OnUpgradesChanged?.Invoke();
 
         // ----- Read API -----------------------------------------------------
 
         /// <summary>True if this player has been granted the given effect.</summary>
-        public bool PlayerHasEffect(BuilderEffectKind kind) => (grantedMask.Value & BitFor(kind)) != 0;
+        public bool PlayerHasEffect(BuilderEffectKind kind) => grantedKinds.Contains((byte)kind);
 
         /// <summary>
         /// Returns this player's <see cref="BuilderEffectDefinition"/> for <paramref name="kind"/>
@@ -113,13 +112,11 @@ namespace TD.Gameplay
         {
             if (!IsServer) return false;
 
-            uint bit = BitFor(kind);
-            if ((grantedMask.Value & bit) != 0) return false;
+            byte value = (byte)kind;
+            if (grantedKinds.Contains(value)) return false;
 
-            grantedMask.Value |= bit;
+            grantedKinds.Add(value);
             return true;
         }
-
-        private static uint BitFor(BuilderEffectKind kind) => 1u << (int)kind;
     }
 }