The Third Edition Dungeon Master's Guide is an essential rulebook for the D&D game and is a must-have for every Dungeon Master. A Dungeon Master runs the Dungeons & Dragons(r) game-part storyteller, part actor, part referee. The Dungeon Master's Guide features 224 pages of beautifully rendered, intuitively presented rules and material designed to get a Third Edition D&D campaign up and running.