Demiplane

Demiplanes

Demiplanes are minor planes, most of which are artificial. They are commonly created by demigods and extremely powerful wizards and psions. Naturally occurring demiplanes are rare; most such demiplanes are actually fragments of other planes that have somehow split off from their parent plane. Demiplanes are often constructed to resemble the Material Plane, though a few—mostly those created by non-humans—are quite alien. Genesis, a 9th level arcane spell or psionic power, and the 9th-level arcane spell Demiplane Seed are among the few printed methods for a player character to create a demiplane.