Material Plane

The Prime Material plane was the plane in which Primatis and the surrounding cosmos existed. The phrase "Prime Material plane," or simply the "Prime," was generally used by beings from other planes in the multiverse, and "primes" was used by the same beings to refer to the inhabitants of the Material Plane.

The Prime Material plane consisted of an infinite expanse filled with a fluid known as phlogiston, within which floated immense crystal spheres, each enclosing an entire system of one or more worlds. Specific conditions varied greatly from one crystal sphere to another, but they were all considered to be part of the same plane.

Being the only plane that intersected both the Ethereal and the Astral, the Prime Material plane occupied an important position as a crossroads of the multiverse, and all other planes were defined in relation to the Prime. The Material Plane in this campaign refers to the world of Primatis, meaning the world between the Inner Planes, the Astral Sea, and the Ethereal Plane.