When playing online, the following rules apply to communication between the KubiTarock client and the KubiTarock server:

• A client can only send a game state change to the server if all active clients are in sync. Only if a client wants to join or leave the session, it must not be in sync itself. If these conditions do not apply, the client automatically repeats the request at 0.5 second intervals. Only if none succeeds after more than 20 attempts, the client is removed from the session.
   
• All changes to the game state sent from the server to a client must be automatically confirmed by the client so that the server can determine the state of synchronization.
   
• If a synchronization failure is detected by the server, a client user can request the server to remove all out-of-sync clients from the session.
   
• If the connection between a client and the server is broken for a long time (about 60 sec), the client is removed from the session.
   
• If a client has been removed from a session by the server. The affected client user can try to log in again.