My setting cosmology brainstorm.

[RangerWickett]

I've got a long-running setting, and though I'm no longer running a game in it, all these new planar books have gotten me a'thinking, "What would my world's planar cosmology be like?"

I've never had much in the way of dimensional travel in my games. A lot of summoning, to be sure, and the elemental forces play a big role, but the closest thing to planar travel was when they tossed an immortal into a portable hole because they couldn't figure out how to kill him.

• Trema. This is the world where the game takes place, earthlike and normal.
• The Sun. Elves believe the sun, named Vona, was the first god to discover this world. There are many gods, and the universe is a big place, so not all of them can know about everything.
• Orbiting Plane(t)s. There are four primary planes in Trema's system, and they all orbit the sun. You can see them in the sky at night, and can teleport there with a high enough level spell. Closest to the sun is the plane of fire, then air. Then comes Trema, then the plane of water, then earth.
• Distant Plane(t)s. In this world, the gods aren't seen. People's beliefs clash, just like in the real world, and you can't know who's right.

There's probably a lot of planes out there, but people usually can't go there, and they have very little tangible presence on the world. I need some sort of hell place and some sort of heaven place from which demons and angels can come, because people have summoned them before, but I want something a little unique. Not an afterlife plane, just a place where really good and really bad things hang out.

I decided that long ago, in the prehistory of the world, a council was convened of those with power, and connections to all but 9 of the planes were sealed. It's still possible to travel from Trema to the plane of demons, and then from there to elsewhere, thus making long-distance interdimensional travel possible. But I wanted to mostly keep weird stuff off Trema.

I know it's not revolutionary, but I'd like some suggestions for things I can do. Of the 9 planes still available, I guess we'd have the four elemental planes, a 'good' plane, and an 'evil' plane. And the sun. That leaves two. What kind of things can I have, do you think? I don't really want alternate material planes, but rather places with weird physical laws. Maybe a huge ring of asteroids, stretching around the system? But most likely that would be one of the sealed planes, since you don't want to open a portal to vacuum.

I have a place called the Heart of History, where time acts funny. Maybe it's an open portal to the Plane of Time? All the other planes might be timeless, but Trema can have time because of this opening.

What else? Hmm. I've got a lot of weird psionics stuff in my world, and that only really showed up in the presence of extraplanar creatures, but then later became part of the world. The most powerful psionic creature in the world was a dragon (native to this world) who was infused with both angelic and demonic power, which allowed her to make her dreams become reality.

Maybe a plane of dreams. And this explains why those 9 planes were left open. Probably in ancient times, when the world was new, it was warred over by creatures of many planes. This happens time and again in the infinity of worlds in the universe, and only those that are able to sieze control of their own borders can survive. So some ancient heroes/villains sealed off the world to keep out unwanted visitors.

You need the elemental forces to keep the world together physically. They're probably the most natural planes to access. Then the plane of time they didn't want to get rid of because they had no idea what would happen without it. The sun you need for light. Dream is similar to time. They were afraid of not having it. Good and Evil, I'm not so sure why they'd have kept those. I don't want to use the 'afraid' idea too many times.

I'm starting to brainstorm up a framework here. Maybe you folks can help me come up with some more. Any help is appreciated, and thank you in advance.

 

[Stormborn]

How about an Etheal or Astral Plane? Not so much as a place where the dead go, but a plane of spirit and dreams. It could be consistant with your elemental planes idea, a Spirit Plane. It could be a kind of gas giant or comet on an excentric orbit around the primary. As it nears Trema there could be more prophecy and magical activity, more dreams and nightmares. It could even be inhabited by an Astral race that seek to enter the minds of the humanoids on Trema, or perhaps could hold the fragments of a sleeping god that inspires a cult on Trema.

 

[DaveStebbins]

Well for two additional planes you could do a plane of the Gods, where all the gods dwell, and maybe a plane of the dead. It's a fairly common cosmology historically, but I don't see it much in D&D/d20.


You could do a plane of shadow and a plane of faerie, which intertwine with the main plane. Recently, I've been thinking of combining the two; where you go depends upon the time of day when you cross over and the two planes are co-planar.

 

[RangerWickett]

Well for two additional planes you could do a plane of the Gods, where all the gods dwell, and maybe a plane of the dead. It's a fairly common cosmology historically, but I don't see it much in D&D/d20.


You could do a plane of shadow and a plane of faerie, which intertwine with the main plane. Recently, I've been thinking of combining the two; where you go depends upon the time of day when you cross over and the two planes are co-planar.

I don't want a realm for the gods, because there are several different religious worldviews in the setting, and they don't agree on how many or what types of gods there are. And instead of a plane of the dead, perhaps a plane that is the passage of the dead. Since there are so many beliefs, people go to many different places as they die, but because this little pocket of the multiverse is a little sealed off, all the dead funnel first through this one dimension. Thus, if someone dies, you can swing by there and try to find him before he passes on.

Basically, I was thinking more like a network of planes. Some are really close, but most are far far away.

The Shadow and Faerie idea are intriguing, but sadly they don't fit this setting. I'll think about it for future places, though.