In the Dungeons & Dragons fantasy role-playing game, Acheron, also known as The Infernal Battlefield of Acheron, is a lawful neutral/lawful 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, Greyhawk and some editions of the Forgotten Realms campaign settings.