Need help with tricky cosmology

[Ry]

I wanted a cosmology that gave me a kind of cross between Spelljammer and Planescape.

Imagine this: There is one transitive plane, which is coextensive with the demiplanes. You can call the transitive the Astral if you want - basically, it's fantasy space with breathable atmosphere. From this space, you can have portals to the demiplanes, which make up most of the campaign setting.

The demiplanes are basically Beyond Countless Doorways-style worlds, complete with Heaven, Hell, Elemental, and all manners of Prime Material worlds.

The trick is this: I want non-euclidean portal geography (i.e. a faster way between two points in plane a than a straight line, by porting to plane b, travelling a shorter distance, and porting back at your destination at plane a) and some kind of relationship between the stars visible in a demiplane and stars in the Astral.

Is there anyone out there who groks to cosmologies that can help me out?

 

[Nyeshet]

One idea that occurred to me during the start of your post is that the stars themselves are portals to other planes - or that the portals exist between sets of stars (perhaps the stars within a constellation, perhaps not).

If the stars themselves are portals, then merely having the stars closer together in some planes will allow for travel such as you suggest. Perhaps, depending on the plane, some stars are closer together while others are further apart - a warping of the plane due to it being only similar - not exact - to the prime. So in the realm of fire stars associated with fire might be nearer each other, while those associated with water or other non-fire related planes could be further apart. This might lead to different night skies in each plane, but if you are very very familiar with the Prime plane's sky and know what to look for, you might be able to determine which plane you are in by how the stars differ from the Prime plane star positions.

Similarly, it would be faster to travel between points in the prime plane that are congruous with other plane themes. A star in the phoenix constellation and a star in the pyrohydra constellation might - in the prime plane sky - be very far apart, maybe even on opposite sides of the night sky, but should you travel though one of the stars you would find yourself in the realm of fire - where these constellations (or at least some of the stars in each) are nearer each other, cutting the travel distance notably compared to journeys entirely through the prime night sky. This slight but notable rearrangement of the stars could actually result in differing constellations in each realm. You may need a new knowledge skill (Knowledge [stellar navigation]) to deal with knowing of this phenomenon and making use of it to find out both which plane you are in and where in the plane you happen to be.

 

[Vraille Darkfang]

I've been working on my cosmology.

It's pretty detailed, & a good part of it is in my head & an AutoCAD File.

But here it is in a Nutshell (Or Crystal Sphere).

Only 1 Planet in the Crystal Sphere is an Actual Planet (the Campaign World, 4th Planet Out).

All other Celestial Bodies are Planar Intrusions.

The 'Sun' is the Positive Energy Plane, orbited by a "Binary" Negative Energy Dwarf Comapnion.

The 'Moons' are Intrusions from the Elemental, Astral, & Ethereal Planes.

Planets are really Outer Planar Intrusions.

This gives me a barrier between Planescape & my Campaign World.

All Planar Travel has to go through the corresponding Planet/Moon first.

 

[Yalius]

OK, visualize this. Your prime plane is 3 dimensions, L, W, H, all orthogonal to each other. Same for the local cosmology; Heaven, hell, various elemental planes are aspects of that plane, just overlayed on top of it, intersecting every point at a 1:1 correspondence; heaven, hell, all the elemental planes share a geography, just in different aspects. Movement between the "local planes" involves whatever method of Plane Shifting or Greater Teleport you prefer.

Orthogonal to those 3 standard directions, you have your transitive plane. You get there by turning at a "right angle" to L, W, and H; for such a transition, you need a special means, a special way of moving; you can travel within that transitive plane, as if you were in arcane space. The further you get into the transitive plane, the further afield you have traveled from your starting plane. As you travel, you see the stars actually swimming, moving, so you can navigate which plane you're traveling to by watching how the stars are arranged. ("Oh, you're looking for the Plane of Burnt Cinders? Watch the constellation of the Ewe, halfway before she becomes the Ogre, you're at the Cinder.") You can have some fun with "transitive plane" storms that make navigation harder, or "burn out" your transition gear, leaving you stranded at the plane you're closest to, for as long as the DM decides.

From the transitive plane, you see the bordering planes as worlds, but to enter and exit them, you have to transit a doorway which could be a physical portal, a tenuous barrier, or just another way of turning. The portals can have any relationship to the local geography you want. You can also take a shortcut by just assuming that the reason you see the different planes and aspects as spheres is because one of the dimensions (L, W, H), in order to make way for the alternate dimension, has to curl up into a ball, changing the perspective that you see of the local planes.

 

[Ry]

These are amazing suggestions... my brain is still crunching away on them to figure out what would be best. I love Nyeshet's constellatoin ideas and Yarius' navigational concept. Brain still crunching...

Definitely I will have this, though: On any given demiplane, when you phase to the transitive you will see all the matter of your demiplane disappear, but the stars will remain.

 

[Andor]

The transitive plain, the field of stars, is linked to the stars and can be reached only from a place directly underneath a star. This give you both your means of faster travel and gives you a multi-planar navigational instrument...

The Astroglobe: Picture three clear plastic spheres of different sizes, nested from smallest to largest. The outermost globe shows the stars in the sky. The middle globe shows the prime material plane (or whatever the PC homeworld is called). The center globe shows the transitive plane. The transitive plane has a point to point correspndence to the material plane (If not neccesarily similar geography) but it is smaller, so travel from point to point moves faster than on the material plane.

So to plot a course from point A to point B you extend a line from the center of the globe out to the sky (Picture a handy laser pointer) Whichever star is closest to being directly overhead is where you go to enter the transitive plane, the star closest to your goal is where you exit the transitive. Assuming the geography of both planes allows it of course.

The actual magical Astroglobe is presumably enchanted cystal rather than clear plastic, but you get the idea.

Now if you really want to screw with your players the stars have colors (some of which may change over time) and these colors show which plane the star is linked to. Most are white which links to the transitive plane, red for the plane of fire, blue for air, etc.. Some stars are multi-colored and link to multiple planes. So now you have several globes of different colors nested one inside the next.

So for example: The PCs need to get to the island of McGuffin. The only star directly over the island is the Dexter Ruby a red star. So the PCs need to travel through the plane of fire to where they can use the dexter ruby portal to travel to the island of McGuffin.

If you really want to screw with them, the skies of the various planes might not be the same, or relate to one another oddly. This could be anything from distortion to reversals or even scrambling. The Astroglobe might have a series of crystal viewing lenses to allow one to see the different skies, or it may be as complex as Olgra's orrey from the Dark Crystal.

Possible plot points:

The bad guys may control the portal spots near their stronghold.

Different planar geographies may cause strange detours. The portal of Ogrivid's Eye may be convenient on your plane but on the transitive plane it's in the middle of a void ocean so you travel to the fairy realm and from there to Ogrivid's Eye and to your destination. (Obviously in this case Ogrivid's Eye links to multiple planes.) If you feel evil you can make some treks a real multiplanar wandering.

The Life Gate portal is a variable star. For 3 days every ten years it turns black and links to a terrible plane. No one has survived journeying there, but an evil wizard plans to cast a spell drawing on the link to that plane. The PCs have to keep him from reaching the portal zone for those three days.

The fallen kingdom of Whatever hid an enormous treasure in a vault on a distant plane. The trouble is no one knows how to get to that plane. But rumour has it that a low level party has found an unknown crystal lens that may reveal the route to the lost plane.

 

[Ry]

Hmm... that helps a lot actually...

How about this:

There are 2 kinds of - the Transitive (stars) and the demiplanes.

From a demiplane, you have two sets of stars. These are the lower and upper firmament.

The lower firmament is your demiplane's sun, sky and any places in the sky that that you could actually physically travel to (planets, asteroids, moons, whatever).

The upper firmament is the stars that form a kind of sphere around your world. In addition to these stars, you can also see some other demiplanes' spheres of stars / upper firmaments. Since they are so far away, they usually appear as single stars.

When you travel from your demiplane to the transitive plane, all of the matter of your plane (and the lower firmament) disappears. All you can see are the upper firmaments. The upper firmament of your local demiplane is of course the closest, but you can still see the distant stars that are actually the upper firmaments of other planes. If you took enough time, you could go directly to the other plane via "sailing" in the transitive. Other objects are in the transitive too (shipwrecks, asteroids, etc.), but were originally brought here from the demiplanes.

Now the question is ... which explanation of what portals are is best? I'm leaning to a combination of the ideas above, where you have to be under a star (that star is actually the distant demiplane) but that star must be passing through a constellation, and that alignment determines where you end up on the destination demiplane depending on that constellation's position in the upper firmament of the destination demiplane. The only problem with this is that it makes constant portals impossible, I think. Can someone show me the way to make these work?

 

[Nyeshet]

Regarding the portals and your words on stars, I should point out that while stars do move and constellations do change in appearance, such occurs over geologic time. From star maps made in ancient times, it is evident that some stars have slightly moved from their former positions. Thus a star could not pass through a constellation - not unless the "star" is in fact a planet or moon.

So perhaps each 'planet' is in fact a distant demiplane, or maybe it is a portal, and where it leads is based upon which constellation it is passing "through." Or, if maybe the constellation determines where in the demiplane the traveler appears if the planet is in fact the demiplane itself.

Hmm, somehow I like the idea of massive wandering variable portals, whose destination (whether to the same demiplane but varying location by portal location, or whether to differing demiplanes - varying based on portal location) can be different in different seasons and different years.

 

[Andor]

While it's true that stars shift over geologic time, and planets move quickly, it's also true that the ancient definition of planets was 'Star the moves' and that's all that was known about them. In any event this is a magical world and you can define things to work however you want them to work.

So if I understand what you want, the sky contains 3 different types of objects.

First the stuff of the lower firmament. This is moons, planets, asteroids, gods, shipwrecks, glowey star krakens, what have you. These objects probably seem to move.

Second the stuff of the Upper Firmament. These are the white stars of the local transative plane and remain fixed in the sky, or at least have a fixed pattern.

Third the stuff of the Outer Dark. These are the distant firmaments of the demiplanes and appear as twinkling multicolored stars. These move, each at their own speed and in it's own direction. (Yes, to move at visible speed a distant star would have to be travelling at ludicrous speed, but this is fantasy and the gods have never heard of einstein, so screw it.)

So for local navigation we have our handy Astroglobe. It has two spheres, and possibly some represention for the lower firmament too. Each plane has it's own astroglobe showing it's local geography and star field. For planar navigation we're back to Olgra's orrey with each globe actually being an astroglobe of a different demi-plane.

So now where a Demi-star is in the sky also shows where you are in it's sky thus allowing you to know where in that plane your portal will reach. (Assuming your Planar Orrey is calibrated correctly of course.)

How's that?

Incidently, for more imagery appropriate to this sort of thing you should read Tomlinson by Kipling. You can find it here.

 

[Ry]

Wow... sometimes I forget how amazing ENWorld can be for creativity.

Demiplane-constellation alignment sounds perfect for determining portals.

One thing I like about this idea is that it makes actual harbour towns still viable - since you don't ever have to escape gravity (just plane shift), harbours make a lot of sense, since if you're a few feet off when you portal back to the Local Demiplane you don't smash your craft on the rocks. There's no onus on spelljamming craft to be able to fly off the surface of the demiplane.

Anyway, I like the idea of the Astroglobe allowing you to figure out where your portal's going to go. I think I'll also use "worlds within" - pocket dimensions, really - which can have a set "orbit" within the rest of the plane in order to keep a particular distant demiplane in alignment through a constellation. These can be seen as a few stars (always defining a sphere, but not obviously so from one angle) that seem like part of the upper firmament but are actually within the sphere (so white, immaterial lights that you can go up to with your spelljamming craft).