diff --git a/src/EcsWorld.cs b/src/EcsWorld.cs
index cff42e2..311bf7e 100644
--- a/src/EcsWorld.cs
+++ b/src/EcsWorld.cs
@@ -101,21 +101,21 @@ namespace DCFApixels.DragonECS
             if (worldID < 0)
             {
                 worldID = (short)_worldIdDispenser.UseFree();
-                if (worldID >= Worlds.Length)
-                {
-                    Array.Resize(ref Worlds, Worlds.Length << 1);
-                }
             }
             else
             {
-                if (Worlds[worldID] != null)
+                if (worldID != _worldIdDispenser.NullID)
                 {
+                    _worldIdDispenser.Use(worldID);
+                }
+                if (_worlds[worldID] != null)
+                {
+                    _worldIdDispenser.Release(worldID);
                     Throw.UndefinedException();
                 }
-                _worldIdDispenser.Use(worldID);
             }
             id = worldID;
-            Worlds[worldID] = this;
+            _worlds[worldID] = this;
 
             _poolsMediator = new PoolsMediator(this);
 
@@ -133,7 +133,7 @@ namespace DCFApixels.DragonECS
             _gens = null;
             _pools = null;
             _nullPool = null;
-            Worlds[id] = null;
+            _worlds[id] = null;
             ReleaseData(id);
             _worldIdDispenser.Release(id);
             _isDestroyed = true;
@@ -393,14 +393,14 @@ namespace DCFApixels.DragonECS
         }
         private void Densify() //уплотнение свободных айдишников
         {
-            _entityDispenser.Sort(); 
+            _entityDispenser.Sort();
         }
         #endregion
 
         #region Upsize
         public void Upsize(int minSize)
         {
-            _entityDispenser.UpSize(minSize);
+            _entityDispenser.Upsize(minSize);
         }
         [MethodImpl(MethodImplOptions.NoInlining)]
         private void OnEntityDispenserResized(int newSize)
diff --git a/src/EcsWorld.static.cs b/src/EcsWorld.static.cs
index 882b3ed..baa3a89 100644
--- a/src/EcsWorld.static.cs
+++ b/src/EcsWorld.static.cs
@@ -21,15 +21,15 @@ namespace DCFApixels.DragonECS
         private const int DEL_ENT_BUFFER_SIZE_OFFSET = 5;
         private const int DEL_ENT_BUFFER_MIN_SIZE = 64;
 
-        private static EcsWorld[] Worlds = new EcsWorld[4];
-        private static IdDispenser _worldIdDispenser = new IdDispenser(4, 0);
+        private static EcsWorld[] _worlds = Array.Empty<EcsWorld>();
+        private static IdDispenser _worldIdDispenser = new IdDispenser(4, 0, OnWorldIdDispenser);
 
         private static List<DataReleaser> _dataReleaseres = new List<DataReleaser>();
         //public static int Copacity => Worlds.Length;
 
         static EcsWorld()
         {
-            Worlds[0] = new NullWorld();
+            _worlds[0] = new NullWorld();
         }
         private static void ReleaseData(int worldID)
         {
@@ -38,8 +38,12 @@ namespace DCFApixels.DragonECS
                 _dataReleaseres[i].Release(worldID);
             }
         }
+        public static void OnWorldIdDispenser(int newSize)
+        {
+            Array.Resize(ref _worlds, newSize);
+        }
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static EcsWorld GetWorld(int worldID) => Worlds[worldID];
+        public static EcsWorld GetWorld(int worldID) => _worlds[worldID];
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static ref T GetData<T>(int worldID) => ref WorldComponentPool<T>.GetForWorld(worldID);
@@ -81,9 +85,9 @@ namespace DCFApixels.DragonECS
             }
             public static int GetItemIndex(int worldID)
             {
-                if (_mapping.Length < Worlds.Length)
+                if (_mapping.Length < _worlds.Length)
                 {
-                    Array.Resize(ref _mapping, Worlds.Length);
+                    Array.Resize(ref _mapping, _worlds.Length);
                 }
                 ref short itemIndex = ref _mapping[worldID];
                 if (itemIndex <= 0)
@@ -101,7 +105,7 @@ namespace DCFApixels.DragonECS
                     {
                         Array.Resize(ref _items, _items.Length << 1);
                     }
-                    _interface.Init(ref _items[itemIndex], Worlds[worldID]);
+                    _interface.Init(ref _items[itemIndex], _worlds[worldID]);
                     _dataReleaseres.Add(new Releaser());
                 }
                 return itemIndex;
@@ -111,7 +115,7 @@ namespace DCFApixels.DragonECS
                 ref short itemIndex = ref _mapping[worldID];
                 if (itemIndex != 0)
                 {
-                    _interface.OnDestroy(ref _items[itemIndex], Worlds[worldID]);
+                    _interface.OnDestroy(ref _items[itemIndex], _worlds[worldID]);
                     _recycledItems[_recycledItemsCount++] = itemIndex;
                 }
             }
diff --git a/src/Internal/IdDispenser.cs b/src/Internal/IdDispenser.cs
index df19e0f..685e1cc 100644
--- a/src/Internal/IdDispenser.cs
+++ b/src/Internal/IdDispenser.cs
@@ -51,18 +51,18 @@ namespace DCFApixels.DragonECS.Internal
 
         #region Use/Reserve/Realese
         /// <summary>Marks as used and returns next free id.</summary>
-        public int UseFree()  //+
+        public int UseFree()
         {
             int ptr = _usedCount;
-            CheckOrResize(ptr);
+            CheckIDOrUpsize(ptr);
             int id = _dense[ptr];
             Move_FromFree_ToUsed(id);
             return id;
         }
         /// <summary>Marks as used a free or reserved id, after this id cannot be retrieved via UseFree.</summary>
-        public void Use(int id)  //+
+        public void Use(int id)
         {
-            CheckOrResize(id);
+            CheckIDOrUpsize(id);
 #if DEBUG
             if (IsUsed(id) || IsNullID(id))
             {
@@ -73,9 +73,9 @@ namespace DCFApixels.DragonECS.Internal
             Move_FromFree_ToUsed(id);
         }
 
-        public void Release(int id)  //+
+        public void Release(int id)
         {
-            CheckOrResize(id);
+            CheckIDOrUpsize(id);
 #if DEBUG
             if (IsFree(id) || IsNullID(id))
             {
@@ -172,13 +172,13 @@ namespace DCFApixels.DragonECS.Internal
         }
         #endregion
 
-        #region UpSize
+        #region Upsize
         [MethodImpl(MethodImplOptions.NoInlining)]
-        public void UpSize(int minSize)
+        public void Upsize(int minSize)
         {
             if (minSize > _size)
             {
-                UpSize_Internal(minSize);
+                Upsize_Internal(minSize);
             }
         }
         #endregion
@@ -189,7 +189,7 @@ namespace DCFApixels.DragonECS.Internal
             _nullID = nullID;
             if (nullID >= 0)
             {
-                CheckOrResize(nullID);
+                CheckIDOrUpsize(nullID);
                 Swap(nullID, _usedCount++);
             }
         }
@@ -205,11 +205,11 @@ namespace DCFApixels.DragonECS.Internal
             return true;
         }
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private void CheckOrResize(int id)
+        private void CheckIDOrUpsize(int id)
         {
             if (id >= _size)
             {
-                UpSize_Internal(id + 1);
+                Upsize_Internal(id + 1);
             }
         }
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -234,7 +234,7 @@ namespace DCFApixels.DragonECS.Internal
             _sparse[sparseIndex] = denseIndex;
         }
         [MethodImpl(MethodImplOptions.NoInlining)]
-        private void UpSize_Internal(int minSize)
+        private void Upsize_Internal(int minSize)
         {
             Resize(ArrayUtility.NormalizeSizeToPowerOfTwo_ClampOverflow(minSize));
         }