DragonsArena is a simple game where players fight against static dragons and win as soon as all dragons are dead. It was a demo game and part of a subject on distributed systems. The objective was to implement the game in a fail-safe manner. We used the mirrored game architecture were the game commands are sent to all servers. Each server implements the Trailing State Synchronization (TSS) ¹ algorithm to have a common game state. In TSS the game state is computed multiple times with delayed time windows to update the game state in case of late incoming messages. The main part of my contribution was the server to server communication which was implemented via ZeroMQ as well as the fail-safe features.