Simulacra

Simulacra is a unique plane in the sense that's origin comes from mortal discovery and creation. Many ages ago, the legendary artificer Mooray designed spells to create pocket dimensions and other extradimensional spaces. As he refined his work, he made sure that each casting of his spells were all linked to the same neutral plane of existence. As his spells were cast among the ages, the spaces grew and grew into the plane of Simulacra.

Following the design of Mooray’s spells, the plane began to form its own new spaces, expanding over time. Eventually, creatures began to form within vacant rooms and spaces created by Mooray's spells. These creatures came to be known as the Modrons. Today, Simulacra is a plane thriving with Modrons with their own societal structure, rules for planar travel, and organization of extradimensional spaces.