Interactivity is one of the most important and distinguishable features of a game. Designing effective interactivity, however, can be a challenge for even the most experienced game developer. This is especially true in the design process of multiplayer online games, so it is critical that developers have a solid understanding of game design and interactivity. Online Game Interactivity Theory is about online game design?its concepts, techniques, and tools. It guides you through the design process for multiplayer online games, beginning with discussions of online game history, the differences between single-player games and online games, and how the various categories of online games affect design. The emphasis throughout the process is on interactivity?how to define it, how to cope with its complexity, and how to integrate it into your designs. Online Game Interactivity Theory defines interactivity on three different levels: player-to-computer, player-to-player, and player-to-game. By understanding the key factors of the three types of interactivity, you will gain insights into how a game?s level of interactivity can influence its potential for success, and what you can do to improve it. Methods for applying interactivity to your online game designs are discussed, and techniques for "designing" it into your games are provided. Details on multiplayer game design issues are also discussed along with guidelines and suggestions for integrating these issues into your games. These guidelines range from community design to the unique importance of a player?s avatar. The book concludes with discussions of valuable tools and strategies that will help improve your workflow. Interviews with some of the most influential people in the computer game industry are also included, to provide insight into their thoughts on online games, the unique features of online game design, and various interpretations of interactivity.