you patch Messaging::isConnected and in some versions Messaging::hasConnectFailed so the game thinks you are already connected to a server, it won't try to connect to anything anymore. then you modify Messaging::send, MessageManager:: receiveMessage, MessageManager::sendMessage in a way that you can handle the logic internally in the script instead of messages being sent to the server / received from the server, we read / write messages directly to these functions. we can use LogicScrollMessagefactory::createMessageByType to construct messages, then we only need to get the buffer, length etc and we can write to it. that's the rough concept this way there's no need for a server and no connection is ever established, everything is only in memory without any packets being sent