The Campaign Sourcebook and Catacomb Guide is a supplement to the Dungeon Master's Guide for the Advanced Dungeons & Dragons 2nd edition rules.
The first section of the book contains general guidelines to help Dungeon Masters (DMs) run campaigns, covering different styles of play, pacing and theatrics, creating campaigns and worlds, enacting believable non-player characters, and make useful maps.
The second part of the book covers running games in dungeons, with rules for underground conditions and instructions for drawing maps in perspective; included are samples of six different styles of dungeon environment.