Goodman Games

Do the Dungeon Crawl Classic World have a set cosmology?

I read reference to the Inner Planes (Elemental)
I read reference to the infernal Planes (specifically the Abyss was mentioned)

What other planes are people using?

Hey, Mike.

No new planes were developed for Áereth. Intentionally, so that the gods and various planes could be adapted to the standard D&D cosmology or your own. It's safe to say that the world does incorporate the allowable planes in the SRD.

As for the Abyss or the Hells, well, those words have been around long before D&D, so they're pretty fair game. But that doesn't mean they have to be the same as the standard D&D equivalents.