In the Dungeons & Dragons fantasy role-playing game, the Abyss, or more fully, the Infinite Layers of the Abyss, is a chaotic evil-aligned plane of existence. It is one of a number of alignment-based Outer Planes that form part of the standard Dungeons & Dragons (D&D) cosmology, used in the Planescape and Greyhawk campaign settings. The Abyss is also the name of one of the faith-based outer planes that form part of the Forgotten Realms cosmology.