Modeling traffic generated by Internet based multiplayer computer games has attracted a great deal of attention in the past few years. In part this has been driven by a need to simulate the network impact of highly interactive online games such as the first person shooter (FPS). Packet size distributions and autocorrelation models are important elements in the creation of realistic traffic generators for network simulators. In this paper we present a simple technique for constructing Markov chains that model autocorrelated packet length for N-player FPS games based on traffic traces of of 2-player games. This enables us to synthesize the time sequence of the length of server to client traffic as well as its probability distribution. We illustrate the likely generality of our approach using data from seven FPS games that have been popular over the past nine years: Half-Life, Half-Life Counterstrike, Half-Life 2, Half-Life 2 Counterstrike, Quake III Arena, Quake 4 and Wolfenstein Enemy Territory.