diff --git a/src/CommandHandlers/ChatMessageHandler.cs b/src/CommandHandlers/ChatMessageHandler.cs
index 4c03b53..cd61b84 100644
--- a/src/CommandHandlers/ChatMessageHandler.cs
+++ b/src/CommandHandlers/ChatMessageHandler.cs
@@ -35,11 +35,7 @@ class ChatMessageHandler : ICommandHandler {
         cmd.Add("p", data);
 
         NetworkPacket packet = NetworkObject.WrapObject(1, 13, cmd).Serialize();
-        foreach (var roomClient in client.Room.Clients) {
-            if (roomClient != client) {
-                roomClient.Send(packet);
-            }
-        }
+        client.Room.Send(packet, client);
 
         cmd = new();
         data = new();
diff --git a/src/CommandHandlers/ExitHandler.cs b/src/CommandHandlers/ExitHandler.cs
index c3be2c6..caee1f7 100644
--- a/src/CommandHandlers/ExitHandler.cs
+++ b/src/CommandHandlers/ExitHandler.cs
@@ -7,6 +7,6 @@ namespace sodoffmmo.CommandHandlers;
 [CommandHandler(26)]
 class ExitHandler : ICommandHandler {
     public void Handle(Client client, NetworkObject receivedObject) {
-        client.LeaveRoom();
+        client.SetRoom(null);
     }
 }
diff --git a/src/CommandHandlers/GauntletHandlers.cs b/src/CommandHandlers/GauntletHandlers.cs
index d337159..c90a583 100644
--- a/src/CommandHandlers/GauntletHandlers.cs
+++ b/src/CommandHandlers/GauntletHandlers.cs
@@ -39,10 +39,7 @@ class GauntletPlayAgainHandler : ICommandHandler
             client.PlayerData.Uid
         }, "msg", room.Id);
 
-        foreach (var roomClient in room.Clients) {
-            if (roomClient != client)
-                roomClient.Send(packet);
-        }
+        room.Send(packet, client);
         room.SendPA(client);
     }
 }
@@ -61,9 +58,7 @@ class GauntletLobbyUserReadyHandler : ICommandHandler
             client.PlayerData.Uid
         }, "msg", room.Id);
 
-        foreach (var roomClient in room.Clients) {
-            roomClient.Send(packet);
-        }
+        room.Send(packet);
 
         if (room.GetReadyCount() > 1) {
             packet = Utils.ArrNetworkPacket(new string[] {
@@ -72,9 +67,7 @@ class GauntletLobbyUserReadyHandler : ICommandHandler
                 client.PlayerData.Uid
             }, "msg", room.Id);
             
-            foreach (var roomClient in room.Clients) {
-                roomClient.Send(packet);
-            }
+            room.Send(packet);
         }
     }
 }
@@ -93,9 +86,7 @@ class GauntletLobbyUserNotReadyHandler : ICommandHandler
             client.PlayerData.Uid
         }, "msg", room.Id);
 
-        foreach (var roomClient in room.Clients) {
-            roomClient.Send(packet);
-        }
+        room.Send(packet);
     }
 }
 
@@ -114,10 +105,7 @@ class GauntletLevelLoadHandler : ICommandHandler
             p.Get<string>("1"),
             p.Get<string>("2") // TODO use size of p.fields - 1
         }, "msg", room.Id);
-        foreach (var roomClient in room.Clients) {
-                roomClient.Send(packet);
-        }
-
+        room.Send(packet);
     }
 }
 
@@ -139,9 +127,7 @@ class GauntletLevelLoadedHandler : ICommandHandler
             room.Id.ToString(),
             (--counter).ToString()
         }, "msg", room.Id);
-        foreach (var roomClient in room.Clients) {
-                roomClient.Send(packet);
-        }
+        room.Send(packet);
         
         timer = new System.Timers.Timer(1500);
         timer.AutoReset = true;
@@ -169,9 +155,7 @@ class GauntletLevelLoadedHandler : ICommandHandler
             timer!.Close();
             timer = null;
         }
-        foreach (var roomClient in room.Clients) {
-            roomClient.Send(packet);
-        }
+        room.Send(packet);
     }
 }
 
@@ -191,10 +175,7 @@ class GauntletRelayGameDataHandler : ICommandHandler
             p.Get<string>("0"),
             p.Get<string>("1")
         }, "msg", room.Id);
-        foreach (var roomClient in room.Clients) {
-            if (roomClient != client)
-                roomClient.Send(packet);
-        }
+        room.Send(packet, client);
     }
 }
 
diff --git a/src/CommandHandlers/GenericMessageHandler.cs b/src/CommandHandlers/GenericMessageHandler.cs
index 7257cde..bb6c41f 100644
--- a/src/CommandHandlers/GenericMessageHandler.cs
+++ b/src/CommandHandlers/GenericMessageHandler.cs
@@ -8,7 +8,6 @@ namespace sodoffmmo.CommandHandlers;
 class GenericMessageHandler : ICommandHandler {
     public void Handle(Client client, NetworkObject receivedObject) {
         NetworkPacket packet = NetworkObject.WrapObject(0, 7, receivedObject).Serialize();
-        foreach (var roomClient in client.Room.Clients)
-            roomClient.Send(packet);
+        client.Room.Send(packet);
     }
 }
diff --git a/src/CommandHandlers/JoinRoomHandler.cs b/src/CommandHandlers/JoinRoomHandler.cs
index 8f7c1d7..b9f7ab0 100644
--- a/src/CommandHandlers/JoinRoomHandler.cs
+++ b/src/CommandHandlers/JoinRoomHandler.cs
@@ -11,7 +11,6 @@ class JoinRoomHandler : ICommandHandler
     {
         string roomName = receivedObject.Get<NetworkObject>("p").Get<string>("rn");
         Room room = Room.GetOrAdd(roomName);
-        Console.WriteLine($"Join Room: {roomName} RoomID: {room.Id} IID: {client.ClientID}");
-        client.JoinRoom(room);
+        client.SetRoom(room);
     }
 }
diff --git a/src/CommandHandlers/PublicMessageHandlers.cs b/src/CommandHandlers/PublicMessageHandlers.cs
index c09133d..86f1257 100644
--- a/src/CommandHandlers/PublicMessageHandlers.cs
+++ b/src/CommandHandlers/PublicMessageHandlers.cs
@@ -24,8 +24,6 @@ class RacingPMHandler : ICommandHandler
         cmd.Add("p", p);
         NetworkPacket packet = NetworkObject.WrapObject(1, 13, cmd).Serialize();
 
-        foreach (var roomClient in client.Room.Clients) {
-            roomClient.Send(packet);
-        }
+        client.Room.Send(packet);
     }
 }
diff --git a/src/CommandHandlers/RacingHandlers.cs b/src/CommandHandlers/RacingHandlers.cs
index 5861d18..d0ee9e3 100644
--- a/src/CommandHandlers/RacingHandlers.cs
+++ b/src/CommandHandlers/RacingHandlers.cs
@@ -58,9 +58,7 @@ class RacingARACKHandler : ICommandHandler
 
         if (room.GetPlayersCount(RacingPlayerState.RaceReady2) == room.ClientsCount) {
             NetworkPacket packet = room.GetSTAPacket();
-            foreach (var roomClient in room.Clients) {
-                roomClient.Send(packet);
-            }
+            room.Send(packet);
             Console.WriteLine($"STA");
         }
     }
diff --git a/src/CommandHandlers/SetPositionVariablesHandler.cs b/src/CommandHandlers/SetPositionVariablesHandler.cs
index 17c3efe..446c385 100644
--- a/src/CommandHandlers/SetPositionVariablesHandler.cs
+++ b/src/CommandHandlers/SetPositionVariablesHandler.cs
@@ -59,11 +59,7 @@ class SetPositionVariablesHandler : ICommandHandler {
         cmd.Add("c", "SPV");
         cmd.Add("p", obj);
 
-
         NetworkPacket packet = NetworkObject.WrapObject(1, 13, cmd).Serialize();
-        foreach (var roomClient in client.Room.Clients) {
-            if (roomClient != client)
-                roomClient.Send(packet);
-        }
+        client.Room.Send(packet, client);
     }
 }
diff --git a/src/CommandHandlers/SetUserVariablesHandler.cs b/src/CommandHandlers/SetUserVariablesHandler.cs
index c745c99..15a35b2 100644
--- a/src/CommandHandlers/SetUserVariablesHandler.cs
+++ b/src/CommandHandlers/SetUserVariablesHandler.cs
@@ -11,6 +11,12 @@ class SetUserVariablesHandler : ICommandHandler {
     Client client;
     string? uid;
     public void Handle(Client client, NetworkObject receivedObject) {
+        if (client.Room == null) {
+            Console.WriteLine($"SUV Missing Room IID: {client.ClientID}");
+            client.Send(NetworkObject.WrapObject(0, 1006, new NetworkObject()).Serialize());
+            client.SheduleDisconnect();
+            return;
+        }
         this.client = client;
         suvData = receivedObject.Get<NetworkObject>("p");
         uid = suvData.Get<string>("UID");
@@ -90,8 +96,7 @@ class SetUserVariablesHandler : ICommandHandler {
         data.Add("vl", vl);
 
         NetworkPacket packet = NetworkObject.WrapObject(0, 12, data).Serialize();
-        foreach (var roomClient in client.Room.Clients)
-            roomClient.Send(packet);
+        client.Room.Send(packet);
 
         NetworkObject cmd = new();
         cmd.Add("c", "SUV");
@@ -105,10 +110,7 @@ class SetUserVariablesHandler : ICommandHandler {
         container.Add("arr", arr);
         cmd.Add("p", container);
         packet = NetworkObject.WrapObject(1, 13, cmd).Serialize();
-        foreach (var roomClient in client.Room.Clients) {
-            if (roomClient != client)
-                roomClient.Send(packet);
-        }
+        client.Room.Send(packet, client);
     }
 
     private void UpdatePlayersInRoom() {
@@ -129,10 +131,7 @@ class SetUserVariablesHandler : ICommandHandler {
         NetworkPacket packet = NetworkObject.WrapObject(0, 1000, data).Serialize();
         packet.Compress();
 
-        foreach (var roomClient in client.Room.Clients) {
-            if (roomClient != client)
-                roomClient.Send(packet);
-        }
+        client.Room.Send(packet, client);
     }
 
     private void SendSUVToPlayerInRoom() {
@@ -144,9 +143,6 @@ class SetUserVariablesHandler : ICommandHandler {
         cmd.Add("p", obj);
 
         NetworkPacket packet = NetworkObject.WrapObject(1, 13, cmd).Serialize();
-        foreach (var roomClient in client.Room.Clients) {
-            if (roomClient != client)
-                roomClient.Send(packet);
-        }
+        client.Room.Send(packet, client);
     }
 }
diff --git a/src/CommandHandlers/WorldEventHandlers.cs b/src/CommandHandlers/WorldEventHandlers.cs
index dd85db8..88fe73e 100644
--- a/src/CommandHandlers/WorldEventHandlers.cs
+++ b/src/CommandHandlers/WorldEventHandlers.cs
@@ -37,9 +37,7 @@ class WorldEventHealthHandler : ICommandHandler {
                 health.ToString("0.0#####", CultureInfo.GetCultureInfo("en-US")) + "," + DateTime.UtcNow.ToString("ddd MMM dd HH:mm:ss UTC yyyy", CultureInfo.GetCultureInfo("en-US")),
                 WorldEvent.Get().GetRoom().Id
             );
-            foreach (var roomClient in WorldEvent.Get().GetRoom().Clients) {
-                roomClient.Send(packet);
-            }
+            WorldEvent.Get().GetRoom().Send(packet);
         }
     }
 }
@@ -59,9 +57,7 @@ class WorldEventFlareHandler : ICommandHandler {
             p.Get<string>("oh") + "," + p.Get<string>("ts"),
             WorldEvent.Get().GetRoom().Id
         );
-        foreach (var roomClient in WorldEvent.Get().GetRoom().Clients) {
-            roomClient.Send(packet);
-        }
+        WorldEvent.Get().GetRoom().Send(packet);
     }
 }
 
@@ -82,9 +78,7 @@ class WorldEventMissileHandler : ICommandHandler {
             p.Get<string>("tID"),
             p.Get<string>("objID")
         });
-        foreach (var roomClient in WorldEvent.Get().GetRoom().Clients) {
-            roomClient.Send(packet);
-        }
+        WorldEvent.Get().GetRoom().Send(packet);
     }
 }
 
diff --git a/src/Core/Client.cs b/src/Core/Client.cs
index f736b91..357e497 100644
--- a/src/Core/Client.cs
+++ b/src/Core/Client.cs
@@ -1,6 +1,7 @@
 using sodoffmmo.Data;
 using System;
 using System.Net.Sockets;
+using System.Runtime.CompilerServices;
 
 namespace sodoffmmo.Core;
 public class Client {
@@ -9,12 +10,12 @@ public class Client {
 
     public int ClientID { get; private set; }
     public PlayerData PlayerData { get; set; } = new();
-    public Room Room { get; private set; }
+    public Room? Room { get; private set; }
 
     private readonly Socket socket;
     SocketBuffer socketBuffer = new();
     private volatile bool scheduledDisconnect = false;
-    private object ClientLock = new();
+    private readonly object clientLock = new();
 
     public Client(Socket clientSocket) {
         socket = clientSocket;
@@ -39,36 +40,36 @@ public class Client {
         try {
             socket.Send(packet.SendData);
         } catch (SocketException) {
-            LeaveRoom();
             SheduleDisconnect();
         }
     }
 
-    public void LeaveRoom() {
-        if (Room != null) {
-            Console.WriteLine($"Leave room {Room.Name} IID: {ClientID}");
-            Room.RemoveClient(this);
-            NetworkObject data = new();
-            data.Add("r", Room.Id);
-            data.Add("u", ClientID);
-
-            NetworkPacket packet = NetworkObject.WrapObject(0, 1004, data).Serialize();
-            foreach (var roomClient in Room.Clients) {
-                roomClient.Send(packet);
-            }
-            Room = null;
-        }
-    }
-    
-    public void JoinRoom(Room room) {
-        lock(ClientLock) {
-            LeaveRoom();
+    public void SetRoom(Room? room) {
+        lock(clientLock) {
+            // set variable player data as not valid, but do not reset all player data
             PlayerData.IsValid = false;
+
+            if (Room != null) {
+                Console.WriteLine($"Leave room: {Room.Name} (id={Room.Id}, size={Room.ClientsCount}) IID: {ClientID}");
+                Room.RemoveClient(this);
+
+                NetworkObject data = new();
+                data.Add("r", Room.Id);
+                data.Add("u", ClientID);
+                Room.Send(NetworkObject.WrapObject(0, 1004, data).Serialize());
+            }
+
+            // set new room (null when SetRoom is used as LeaveRoom)
             Room = room;
-            Room.AddClient(this);
+
+            if (Room != null) {
+                Console.WriteLine($"Join room: {Room.Name} RoomID (id={Room.Id}, size={Room.ClientsCount}) IID: {ClientID}");
+                Room.AddClient(this);
+
+                Send(Room.SubscribeRoom());
+                UpdatePlayerUserVariables();
+            }
         }
-        Send(Room.SubscribeRoom());
-        UpdatePlayerUserVariables();
     }
 
     private void UpdatePlayerUserVariables() {
@@ -91,6 +92,12 @@ public class Client {
     }
 
     public void SheduleDisconnect() {
+        if (Room != null) {
+            // quiet remove from room (to avoid issues in Room.Send)
+            //  - do not change Room value here
+            //  - full remove will be will take place Server.HandleClient (before real disconnected)
+            Room.RemoveClient(this);
+        }
         scheduledDisconnect = true;
     }
 
diff --git a/src/Core/GauntletRoom.cs b/src/Core/GauntletRoom.cs
index 19c6dfd..1f6fb4d 100644
--- a/src/Core/GauntletRoom.cs
+++ b/src/Core/GauntletRoom.cs
@@ -65,9 +65,7 @@ public class GauntletRoom : Room {
         }
         NetworkPacket packet = Utils.ArrNetworkPacket(info.ToArray(), "msg", base.Id);
 
-        foreach(var player in players) {
-            player.Key.Send(packet);
-        }
+        Send(packet);
     }
 
     public void SendPA(Client client) {
@@ -112,10 +110,7 @@ public class GauntletRoom : Room {
             }
             NetworkPacket packet = Utils.ArrNetworkPacket(info.ToArray(), "msg", base.Id);
 
-            foreach(var player in players) {
-                player.Key.Send(packet);
-            }
-
+            Send(packet);
             return true;
         }
     }
@@ -127,8 +122,8 @@ public class GauntletRoom : Room {
             if (room is null)
                 room = GauntletRoom.Get();
 
-            room.AddPlayer(client); // must be call before JoinRoom (before InvalidatePlayerData) - we need uid
-            client.JoinRoom(room);
+            client.SetRoom(room);
+            room.AddPlayer(client); // client will be not removed from GauntletRoom.players ... after remove all client from room whole GauntletRoom.players will be removed
             room.SendUJR();
         }
     }
diff --git a/src/Core/Racing.cs b/src/Core/Racing.cs
index c6057d5..843d784 100644
--- a/src/Core/Racing.cs
+++ b/src/Core/Racing.cs
@@ -94,9 +94,7 @@ public class RacingRoom : Room {
             }
 
             NetworkPacket packet = Utils.ArrNetworkPacket(info.ToArray(), "", Id);
-            foreach (var roomClient in Clients) {
-                roomClient.Send(packet);
-            }
+            Send(packet);
         }
     }
 
@@ -124,8 +122,7 @@ public class RacingRoom : Room {
 
     private void SendJoin(Object? source, ElapsedEventArgs e) {
         foreach(var player in players) {
-            Console.WriteLine($"Join Racing Room: {Name} RoomID: {Id} IID: {player.Key.ClientID}");
-            player.Key.JoinRoom(this);
+            player.Key.SetRoom(this);
         }
         SetTimer(1, CountDown, true);
     }
@@ -142,9 +139,7 @@ public class RacingRoom : Room {
                     "LT",
                     (--counter).ToString()
                 }, "", Id);
-                foreach (var roomClient in Clients) {
-                    roomClient.Send(packet);
-                }
+                Send(packet);
             }
         }
     }
@@ -167,9 +162,7 @@ public class RacingRoom : Room {
             "",
             "ST"
         }, "", Id);
-        foreach (var roomClient in Clients) {
-            roomClient.Send(packet);
-        }
+        Send(packet);
     }
 
     // TODO StratTimer → kick out to main lobby players without RacingPlayerState.RaceReady1 after timeout, next kick out players without RacingPlayerState.RaceReady2 after timeout2
diff --git a/src/Core/Room.cs b/src/Core/Room.cs
index 39748eb..741ff29 100644
--- a/src/Core/Room.cs
+++ b/src/Core/Room.cs
@@ -66,6 +66,14 @@ public class Room {
         }
     }
 
+    public void Send(NetworkPacket packet, Client? skip = null) {
+        foreach (var roomClient in clients) {
+            if (roomClient != skip) {
+                roomClient.Send(packet);
+            }
+        }
+    }
+
     public static bool Exists(string name) => rooms.ContainsKey(name);
 
     public static Room Get(string name) => rooms[name];
@@ -99,7 +107,7 @@ public class Room {
         roomInfo.Add((short)0); // max spectator count
 
         NetworkArray userList = new();
-        foreach (Client player in Clients) {
+        foreach (Client player in clients) {
             if (player.PlayerData.Uid != "")
                 userList.Add(player.PlayerData.GetNetworkData(player.ClientID, out _));
         }
diff --git a/src/Core/WorldEvent.cs b/src/Core/WorldEvent.cs
index 81c6da2..4640ce0 100644
--- a/src/Core/WorldEvent.cs
+++ b/src/Core/WorldEvent.cs
@@ -160,9 +160,7 @@ class WorldEvent {
                 lastResults,
                 room.Id
             );
-            foreach (var roomClient in room.Clients) {
-                roomClient.Send(packet);
-            }
+            room.Send(packet);
             
             NetworkArray vl = new();
             vl.Add(NetworkArray.VlElement("WE__AI", NetworkArray.NULL));
@@ -171,9 +169,7 @@ class WorldEvent {
                 vl.Add(NetworkArray.VlElement("WEF_" + t.Key, NetworkArray.NULL));
             }
             packet = Utils.VlNetworkPacket(vl, room.Id);
-            foreach (var roomClient in room.Clients) {
-                roomClient.Send(packet);
-            }
+            room.Send(packet);
             
             Console.WriteLine($"Event {uid} sent _End");
             
@@ -206,9 +202,7 @@ class WorldEvent {
         Console.WriteLine($"Event {uid} send event notification (WE_ = {(WE ? startTimeString : WE)}  WEN_ = {(WEN ? nextStartTimeString : WEN)}, room = {room.Id}) to all clients");
         NetworkPacket packet = Utils.VlNetworkPacket(EventInfoArray(WE, WEN), room.Id);
         foreach (var r in Room.AllRooms()) {
-            foreach (var roomClient in r.Clients) {
-                roomClient.Send(packet);
-            }
+            r.Send(packet);
         }
     }
     
diff --git a/src/Server.cs b/src/Server.cs
index 2001576..0d7a1dd 100644
--- a/src/Server.cs
+++ b/src/Server.cs
@@ -53,7 +53,7 @@ public class Server {
             }
         } finally {
             try {
-                client.LeaveRoom();
+                client.SetRoom(null);
             } catch (Exception) { }
             client.Disconnect();
             Console.WriteLine("Socket disconnected IID: " + client.ClientID);