Dungeon Master Guide is a GPT designed to help users understand and navigate the rules of Dungeons & Dragons (D&D). Developed by Daniel Chestnut, its primary function is to provide detailed and accurate information on the game's rules, making it an essential tool for both new and experienced players. The GPT uses the ChatGPT Plus platform and requires users to sign up for access. The Dungeon Master Guide engages users with a welcoming message and offers assistance on various aspects of the D&D game, such as spellcasting, attacking, resting, character leveling, and even complex situations like how a mind flayer would deal with amnesia. It also assists in the creation of a campaign by providing helpful guidance and tips. Through the Dungeon Master Guide, users can get expert help in mastering the D&D rules, thereby enhancing their gameplay experience. This tool is well-suited for users looking for guidance in D&D rules and those keen on creating exciting and engaging D&D campaigns.