Systems and methods are provided for the close coupling of Session Initiation Protocol (SIP) based Voice over Internet Protocol (VoIP) with multiplayer network games. Game state dependent voice communications are used as another method of player interaction in the game environment. The system uses SIP enhanced game servers and conference servers with audio mixing capabilities, and the game server controls the creation, maintenance and changing of the voice conferences. Participation in a voice conference is determined by the game state features associated with each player including distance and direction to determine how the voices are mixed in a voice conference.