Every medium has a unique voice with which it can speak, and it is the responsibility of the user of a medium to find that voice. Computer games have a voice that I firmly believe to be as strong as that available in any other media. Computer games are a relatively young form when compared with the likes of the printed word, music, the visual arts, or the theater, and I think this currently works against the likelihood of computer games truly finding their most powerful voice. This book is an attempt to help readers find that voice in their own projects. This can come in both the more theoretical form of questioning why it is that players play games , but also in the entirely more practical form of how to most effectively work with playtesters . To have any chance of producing a great game, the game designer must understand both the theoretical aspects and the practical necessities of game design.