The Planes

In addition to the 16 Outer Planes, There are three Transitive planes, The elemental and quasi-elemental planes, and numerous demiplanes and divine realms.

The Outer Planes

The ultimate destinations of most petitioners and deceased souls, most divine realms can be found on the outer planes. Those that do not end up claimed by one god or another upon their passing still usually end up on the outer planes due to their outlook or alignment.

As the cycle of souls mainly flows to these planes, their rulers and denizens tend to be the most powerful entities vying for influence among the planes. From attempting to spread their faiths and outlook to claim more souls to claiming pieces of the Outlands to their respective layers, Celestials, Fiends, Modrons and the Slaad alike participate in this great game.

The Transitive Planes

The Astral Plane, the Shadow Plane, and the Ethereal Plane constitute transitive planes. Unlike the Inner and Outer Planes, or the various Prime Materials, the Transitive Planes are in-between places, overlaid in the spaces above, below, and between the other planes. As such, few souls make their final homes here, and few divine realms can be found on these planes.

However, fiends and undead often lair in the shadow plane, and the river of souls flows through the astral for much of its journey. In addition, the Boneyard of the final judge is generally considered to be a demiplane within or adjacent to the Astral.

The Inner Planes

The four primary elemental planes, the positive and negative energy planes, as well as various quasi and paraelemental planes comprise the Inner Planes. As they do not partake of the flow of souls, the elementals have generally less interest in the politics of the planes than the denizens of the Outer Planes. However, this does not make them unimportant as the elemental planes are in some sense the initial source of all power on the planes. From the endless fires of the fire plane to the unending masses of rock and stone on the earth plane, many even believe that the positive energy plane is the ultimate source of the souls that feed the cycle of the planes.