Dungeon Master's Guide

The Dungeon Master's Guide (DMG or DM's Guide; in some printings, the Dungeon Masters Guide or Dungeon Master Guide) is a book of rules for the fantasy role-playing game Dungeons & Dragons. The Dungeon Master's Guide contains rules concerning the arbitration and administration of a game, and is intended for use by the game's Dungeon Master.

The Dungeon Master's Guide is a companion book to the Player's Handbook, which contains all of the basic rules of gameplay, and the Monster Manual, which is a reference book of statistics for various animals and monsters. The Player's Handbook, Dungeon Master's Guide, and Monster Manual are collectively referred to as the "core rules" of the Dungeons & Dragons game. Both the Dungeon Master's Guide and the Player's Handbook give advice, tips, and suggestions for various styles of play.

While all players, including the Dungeon Master, are expected to have at their disposal a copy of the Player's Handbook, only the Dungeon Master is expected to refer to the Dungeon Master's Guide or Monster Manual during gameplay.