Canon:Inner Planes

Inner planes are manifestations of the basic building blocks of the universe. Each is generally made up of a single type of energy or element that overwhelms all others. The natives of a particular inner plane are well adapted to their environment, and do not generally need things from outside of the plane to survive. Elementals, elemental weirds, and various genies are common natives.

The actual inner planes present within a game, the details of their environments, as well as their cosmological orientation depend on the specific campaign setting.

In the Planescape campaign setting the inner planes are the four elemental planes of air, fire, earth and water, the paralemental planes between them - smoke, magma, ooze and ice - the positive and negative energy planes, and the quasielementel planes between the elemental and energy planes. The positive quasielemental planes are lightning, radiance, mineral and steam, the negative ones are vacuum, salt, dust and ash.

In the Dark Sun campaign setting, there exist next to the four elemental planes of air, fire, earth and water the paraelemental planes of sun, magma, silt and rain.