game state update structure and distribution in MMO? I'm developing an MMO, which has to maintain a global game state. Now I want to distribute the updates, which the players make to this state, to players which can see those updates (area of interest etc.) Is there a common structure format for these updates and for a global game state? Like, every action a player sends to the server has to include a type, the coordinates etc. And are the updates, which gets distributed from the server to the players in the same format or are they different? Also should I include timestamps or use the receive time from the server to check which action came first and which sencond etc.? And what should I send back to the player if he send an invalid action?