The Outer Planes is a term from Dungeons & Dragons introduced in the Planescape setting. It is a way of collectively referring to the various alignment-based afterlife planes that are the backbone of the Planescape setting, as these planes exist "outside" of the Inner Planes and are subsequently seen as the most important parts of the multiverse, at least by the residents of Sigil. The Outer Planes can be divided by general alignment category into the Upper Planes (Good), Middle Planes (Neutral) and Lower Planes.
|The Cosmology of Planescape|
|Inner Planes||Ethereal Plane||Prime Material||Astral Plane||Outer Planes|
|Elemental Planes||Energy Planes||Demiplane of Dread||Plane of Shadow||Plane of Mirrors|
|World Serpent Inn||Tu'narath||Sigil||Demiplanes||Ordial Plane?|