Mordenkainen's Magnificent Mansion is a spell in the Dungeons & Dragons role-playing game that allows a caster to create a luxurious, temporary dwelling. The mansion appears in an extra-dimensional space, providing a safe haven for the caster and their companions. It features lavish furnishings, a fully stocked kitchen, and ample room for guests, making it an ideal retreat during adventures. The spell lasts for 24 hours and can be summoned once per day. It is named after the powerful wizard Mordenkainen, a prominent character in the game's lore. The mansion is accessible through a magical door that vanishes after the spell ends.