diff --git a/src/tool/Syroot.Worms.Worms2.GameServer/Server.cs b/src/tool/Syroot.Worms.Worms2.GameServer/Server.cs
index 73d6e03..e2ff127 100644
--- a/src/tool/Syroot.Worms.Worms2.GameServer/Server.cs
+++ b/src/tool/Syroot.Worms.Worms2.GameServer/Server.cs
@@ -128,55 +128,29 @@ namespace Syroot.Worms.Worms2.GameServer
             }
         }
 
-        private void LeaveGame(User fromUser)
-        {
-            // Close an abandoned game.
-            Game? game = _games.SingleOrDefault(x => x.Name == fromUser.Name);
-            if (game == null)
-                return;
-
-            _games.Remove(game);
-
-            // Notify other users.
-            foreach (User user in _users.Where(x => x != fromUser))
-            {
-                SendPacket(user.Connection, new Packet(PacketCode.Leave,
-                    value2: game.ID,
-                    value10: fromUser.ID));
-                SendPacket(user.Connection, new Packet(PacketCode.Close,
-                    value10: game.ID));
-            }
-        }
-
-        private void LeaveRoom(User fromUser)
+        private void LeaveRoom(Room? room, int leftID)
         {
             // Close an abandoned room.
-            bool roomClosed = fromUser.RoomID != 0
-                && !_users.Any(x => x != fromUser && x.RoomID == fromUser.RoomID)
-                && !_games.Any(x => x.RoomID == fromUser.RoomID);
+            bool roomClosed = room != null
+                && !_users.Any(x => x.ID != leftID && x.RoomID == room.ID)
+                && !_games.Any(x => x.ID != leftID && x.RoomID == room.ID);
             if (roomClosed)
-                _rooms.Remove(_rooms.Single(x => x.ID == fromUser.RoomID));
+                _rooms.Remove(room!);
 
             // Notify other users.
-            foreach (User user in _users.Where(x => x != fromUser))
+            foreach (User user in _users.Where(x => x.ID != leftID))
             {
                 // Notify room leave, if any.
-                if (fromUser.RoomID != 0)
+                if (room != null)
                 {
                     SendPacket(user.Connection, new Packet(PacketCode.Leave,
-                        value2: fromUser.RoomID,
-                        value10: fromUser.ID));
+                        value2: room.ID,
+                        value10: leftID));
                 }
                 // Notify room close, if any.
                 if (roomClosed)
-                {
-                    SendPacket(user.Connection, new Packet(PacketCode.Close,
-                        value10: fromUser.RoomID));
-                }
+                    SendPacket(user.Connection, new Packet(PacketCode.Close, value10: room!.ID));
             }
-
-            // Update user room.
-            fromUser.RoomID = 0;
         }
 
         // ---- Handlers ----
@@ -349,16 +323,16 @@ namespace Syroot.Worms.Worms2.GameServer
             // Require valid room ID (never sent for games, users disconnect if leaving a game).
             if (packet.Value2 == fromUser.RoomID)
             {
-                LeaveRoom(fromUser);
+                LeaveRoom(_rooms.FirstOrDefault(x => x.ID == fromUser.RoomID), fromUser.ID);
+                fromUser.RoomID = 0;
+
                 // Reply to leaver.
-                SendPacket(connection, new Packet(PacketCode.LeaveReply,
-                    error: 0));
+                SendPacket(connection, new Packet(PacketCode.LeaveReply, error: 0));
             }
             else
             {
                 // Reply to leaver.
-                SendPacket(connection, new Packet(PacketCode.LeaveReply,
-                    error: 1));
+                SendPacket(connection, new Packet(PacketCode.LeaveReply, error: 1));
             }
         }
 
@@ -368,10 +342,27 @@ namespace Syroot.Worms.Worms2.GameServer
             if (fromUser == null)
                 return;
 
+            int roomID = fromUser.RoomID;
+            int leftID = fromUser.ID;
             _users.Remove(fromUser);
 
-            LeaveGame(fromUser);
-            LeaveRoom(fromUser);
+            // Close an abandoned game.
+            Game? game = _games.SingleOrDefault(x => x.Name == fromUser.Name);
+            if (game != null)
+            {
+                roomID = game.RoomID;
+                leftID = game.ID;
+                _games.Remove(game);
+                // Notify other users.
+                foreach (User user in _users.Where(x => x != fromUser))
+                {
+                    SendPacket(user.Connection, new Packet(PacketCode.Leave, value2: game.ID, value10: fromUser.ID));
+                    SendPacket(user.Connection, new Packet(PacketCode.Close, value10: game.ID));
+                }
+            }
+
+            // Close any abandoned room.
+            LeaveRoom(_rooms.FirstOrDefault(x => x.ID == roomID), leftID);
 
             // Notify user disconnect.
             foreach (User user in _users)
@@ -395,12 +386,12 @@ namespace Syroot.Worms.Worms2.GameServer
         private void OnCreateGame(PacketConnection connection, Packet packet)
         {
             User? fromUser = GetUser(connection);
-            if (fromUser == null || packet.Value1 != 0 || packet.Value2 == null || packet.Value4 != 0x800
+            if (fromUser == null || packet.Value1 != 0 || packet.Value2 != fromUser.RoomID || packet.Value4 != 0x800
                 || packet.Data == null || packet.Name == null || packet.Session == null)
                 return;
 
-            // Require valid room ID.
-            if (packet.Value2 == fromUser.RoomID)
+            // Require valid room ID and IP.
+            if (connection.RemoteEndPoint.Address.Equals(IPAddress.Parse(packet.Data)))
             {
                 Game newGame = new Game(++_lastID, fromUser.Name, fromUser.Session.Nation, fromUser.RoomID,
                     connection.RemoteEndPoint.Address, // do not use bad NAT IP reported by users here
@@ -420,15 +411,11 @@ namespace Syroot.Worms.Worms2.GameServer
                 }
 
                 // Send reply to host.
-                SendPacket(connection, new Packet(PacketCode.CreateGameReply,
-                    value1: newGame.ID,
-                    error: 0));
+                SendPacket(connection, new Packet(PacketCode.CreateGameReply, value1: newGame.ID, error: 0));
             }
             else
             {
-                SendPacket(connection, new Packet(PacketCode.CreateGameReply,
-                    value1: 0,
-                    error: 1));
+                SendPacket(connection, new Packet(PacketCode.CreateGameReply, value1: 0, error: 2));
             }
         }