World

A world is a unique planet or other solid mass on which complex ecosystems and sapient life flourish. Each universe has exactly one plane unaffiliated with any alignment or element -- called a "World Plane," "Material Plane," or "Prime Materials Plane," among other names -- which contains exactly one world. Although planes may contain any number of planets or other independent land masses, each universe can have only one world. This world is usually home to the universe's mortal races, and is generally the central setting for most of the universe's stories. A universe and its world are often conflated; a universe's name is usually assigned by scholars from the name its inhabitants give its world.

Corvus
The universe of Corvus is the solitary exception to the rules outlined above -- Corvus is the only universe to have, in fact, three worlds on its World Plane: Parthoris, Cronos, and Thyrion. Because of this, Corvus is also the only universe to have its own name, rather than being assigned the same name as one of its worlds.