MUDs (Multi-User Dimensions or Multi-User Dungeons, depending on who you ask) are Internet-based role-playing games that allow you to join players from around the world anytime. If that appeals to you, here's the book to get you started. While it concentrates primarily on adventure/action games, it also contains information on the growing number of socially-oriented games, where interaction among players is more important than slashing monsters. The authors show you where to find games, how to join them and share valuable strategies.