Abstract—We present a generic tool, Kartograph, that lifts the fog of war in online real-time strategy games by snooping on the memory used by the game. Kartograph is passive and cannot be detected remotely. Motivated by these passive attacks, we present secure protocols for distributing game state among players so that each client only has data it is allowed to see. Our system, OpenConflict, runs real-time games with distributed state. To support our claim that OpenConflict is sufficiently fast for real-time strategy games, we show the results of an extensive study of 1000 replays of Starcraft II games between expert players. At the peak of a typical game, OpenConflict needs only 22 milliseconds on one CPU core each time state is synchronized.