Impact of Network Loss/Delay Characteristics on Consistency Control in Real-Time Multi-Player Games

In this paper, we study the impact of network-level message loss/delays on the performance experienced by the players in a real-time multi-player game. The study is conducted through the prism of consistency models of the game state (logically) shared among the players. We employ a weaker notion of consistency that encompasses: (i) the real-time persistence effects of player actions in the physical game world; and (ii) the state obsolescence caused by the loss/delay of player and game server messages in the network. Both (i) and (ii) impact the realism and cohesiveness of the game being played. The user-level performance measure, namely, the player-level lag, is studied for multi-player games under realistic settings of network communications and human participation. Towards this end, the paper formulated a formal model of multiplayer games and then studied the effects of network delays and human persistence on the player-level lags experienced. Sample games studied are the Soldier of Fortune and the RogueSpear. The methodology can be employed for studying the the effectiveness of human elements participating in the collaborative simulation of a physical world (such as war games).