Blackmoor Multiverse

[Havard]

To what extent was there planar travel in the original Blackmoor campaign, and is there a definitive list of planes that existed in the setting before the D20 era version of the setting and MMRPG? Are there specific references we can find in the FFC or the DA modules? I haven't looked through them for planar references yet, but the necessity of planes described in the 5E DMG got me thinking about this.

Original Campaign/FFC
Cosmology seems vague. Different Worlds/Time travel is definitely a thing. Characters are able to travel to Blackmoor from Earth, Tekumel etc. Demons, Gods, Elementals likely have their own realms. Characters visit Earth to fight Nazis, WWII era Japanese etc.

TSR Era: I assume BECMI cosmology is in place.

D20 Era: Everything from the list above is assumed to be in place.


-Havard