Imagine that you have a Spelljammer-like fantasy universe with all kinds of exotic worlds, suns, gas giants...

Gonna dump a brief overview of the core elemental planes I'm dropping in this "planescape rebuild" I'm working on, wanna know if this makes them a bit more interesting sounding than usual and is worded in a way that makes it easy to visualise the general "landscape" of the planes. It's about 2000 words so far and I haven't finished writing up the paraplanes yet:
>Central to the multiverse in the sense that they are the font from which all physical matter in the universe ultimately derives its essence from, are the inner planes. Here lie the 4 elemental planes of earth, water, air and fire, the twin and apposite energy planes of negativity and positivity, the four para-elemental planes of Ooze, Ice, Magma and Smoke, which separate the elemental planes from each other (or intermingle and connect the elemental planes, depending on how you want to think of it). Finally the eight quasi-elemental planes of Ash, Dust, Salt, Vacuum, Mineral, Radiance, Lightning and Steam, that represent the positive and negative evolutions of the elemental planes.
Each of these planes is by definition completely alien and different in its material nature from each other, but there are a few commonality amongst the planes:
>Many of these planes are internally separated into layers often referred to as the "Elemental Seas", the "lower" or "bottom" layer will often be more substantial or more opaque in nature than the planes' "top" or "upper" layer. Less common are the consistent planes, where the plane is almost entire made of their fundamental material in all directions, with generally finite and variously shaped areas where the form of the fundamental material often changes or an element closely related to the element predominates in place of the usual material of the plane. Finally are the Energetic planes that are utterly immaterial in nature and filled diffusely with the elemental or para-elemental or quasi-elemental "substance" (or their absence in the case of the plane of Vacuum).

>The Elemental Planes
> As the archetypical example of an "elemental sea", the Plane of Water is divided into the Great Blue Ocean and the Vaporous Sky, with a clear and sharp boundary akin to the surface of any ocean. On this infinite surface the great ship-cities of the elemental courts sail both above and below the surface of the Ocean (as does the afterlives of sailors who die to the water's whims in the Prime and outer planes), plying their trades or defending themselves from evil elemental pirates and occasional planar kraken and leviathans. As is common with almost all of these elemental "seas", the seeming "air" above the Great Blue is however not truly air despite seeming clear and lacking the omnipresent blue glow found even at the deepest depths of the Great Blue, but is actually water vapour and so still requires extra-planar visitors to retain some means of breathing suitable for the ocean itself.

Goddamn. Just use the Basic line's default inner planes.

> Similarly there is the Great Lake of Fire in the Plane of Fire, above which the Heated Reaches extend indefinitely. This "lake of fire" is more notional than Water's, and its surface is merely where the licking tongues of the great flames from the depths of the fire plane come to an end in a dancing, roiling sea that extends down and across for infinite distance. The apparent empty space above this ocean shimmers and bends the image of anything viewed through it and is made up of the pure and largely invisible convective heat that surrounds any flame (and is disturbingly not made up of the hot air that usually conveys this heat in mundane flames). Anything that would crisp and blacken inside the ocean of fire instead roasts and bakes dryly above it. Unlike the plane of water, it is in the "skies" above the ocean of fire that the majority of the denizens reside. In those skies float the vast evil "hot air" balloon-cities that stay aloft above the ocean of fire via the slow and agonising torture of air elemental slaves captured in interplanar raids, which provides ample boyancy for entire cities of elementals. The kinder denizens of Fire distinguish themselves from their evil denizens in vast winged ships that soar and glide atop the thermals of the plane's sky, or dive and dip into the lake of fire to power their elemental engines.

No! The weird lack of shit to do combined with being hard to fucking grok is a known problem with the innerplanes' usual forms. So I'm fucking with them.

> Earth is often taken as the archetypical "consistent" plane, for the plane of earth lacks any such "seas" or even "lakes". Instead the plane is one vast and crushing block of earth, rock and soil. Here there is no "top" nor "bottom", now easy travel or movement "through" the endless material that actively strives to resist anyone who tries to actively dig or move through its material. But even on this seemingly monotonous plane are strewn the "Earth Cracks", each seemingly vast as the plane itself and where there is space enough for extra-planar life to struggle and live. These normally unlit interior spaces have been cause for lost or ignorant plane-walkers to mistake the plane for the caverns of Pandemonium or even, when viewing from afar the more heavily populated "cavern cities" that sometimes line the sides of these cracks, Bytopia. Theories as to the origins of these cracks are wild and varied - and largely don't matter. No crack has yet to observed appearing in the plane, nor has anyone lived to tell the tale of experiencing any crack closing again.
>A question an observant reader might now be wondering, given the examples of the other elemental planes, "what fills the gaps in the cracks, if not air?" Well, much like the plane of fire, the space between the cracks is one filled with the pure essence of incredible high and crushing pressures. Not, to be clear, high pressure air, dirt or even fine dust, but rather pressure itself is the medium filling the cracks of the plane of earth, and any entity not attuned to the plane or otherwise protected from the plane's nature by some means will find their body flattened and collapsed in upon itself as though it had fallen to the very bottom of the prime's farthest ocean depths and then carefully dried out.

> The Plane of Air is another example of a consistent plane, lacking any single ocean in place of so called immense but finite "cloud lakes" which float endlessly through the clean fresh air of the rest of the plane. These absently wander in no notable directions and with no consistent alignment to each other or anything else in the plane. Though the term "cloud" is misleading for the cloud lakes are not made up of the water vapour a cloud on the prime would be, but rather seems to contain the essence of what a cloud looks like, though not its planar substance (which can be found within the vaporous sky of the plane of water, and sometimes descends in cloying fogs upon the surface of the Great Blue). Here it is the "inside" of the "lakes" that are the busiest and most bustling sites of elemental civilisations, for inside the clouds those who wish to remain or move unseen in the otherwise boundless clarity of the plane of Air find cover and solitude. Air Elementals often maintain courts within the clouds and near them, taking pride in their ability to collectively steer their vast "cloud islands" whose substance is allegedly formed out of the usually insubstantial stuff of the plane's "Clouds".

wait, is that some skypeia shit? of course not, nobody liked that weird setting...

(skipping the energy planes because they're unchanged from standard presentation)
>The Quasi-Elemental Planes

> Separating the Elemental Planes from the Energy Planes are the four quasi-planes. Radiance and Lightning both have a similar energy based nature to the energy planes and lack physicality, though it is in the plane of lightning that the Entish hells reside, and in the plane of radiance that the Prismatic Cities are found, places where dying angels visit to blind themselves in preparations for their move beyond their current form. Steam is notable not for having seas so much as streams, vast columns of more energetic and opaque steam separate from the ambient heated water that makes up the rest of the plane. These areas of heavier steam form tubules of various sizes and widths that twist and curl throughout the plane, of which the most amazing is the Grand Curl, a tubule vaster than any other so far found or recorded, that curls up like the tail of a pig to form a vast tunnel down its center, in which the Steam Courts and Great Brass Ships of the plane's major inhabitants are found.
> Finally for the positive aligned quasi-planes there is the plane of minerals, that is a plane much like that of elemental earth, with fewer and smaller cracks lined with vicious and jagged jewelled protrusions as tall as buildings, and where everything is lit with a light that shines from within the depths of the minerals that make up the substance of the plane and walls of the cracks.

>Most of the negative aligned quasi-planes differ again from the other planes in their formation by being separated into vast barren deserts and empty blackened skies, sometimes mockingly referred to as the "sea"s of Ash, Dust and Salt.
> Vacuum is again a plane of undifferentiated nothingness, like the energy planes, and aside from some planar groups and entities that have adopted the plane, little of note exists inside of its unending and unrelenting nothingness. The desert seas of the other three planes are unique though in that upon their surface, when the dust, salt and ashen storms are not blinding or stripping the skins off of any visitor, it is possible to glimpse like a distant moon the eye watering negative glare of the negative energy plane itself, which hangs in the sky with seemingly finite size. This is said to be a mirage caused by seeing another infinite plane from within another infinite plane, and the dual infinites causing the skies to falter and lie (whatever that means) in a fashion which even the most dry witted of scholars would admit is a fitting trait for these hellish planes.

> The Desert of Ash furthermore has unique features upon its surface in the form of piles and plains of still warm embers, so called Ash-Tree Forests (not to be confused with a forest made up of Ash trees) can even be found where the blackened barks and ashy leaves of these strange protrusions seem to be constantly in the process of shedding, as though locked eternally in a state of autumn.
> The Desert of Salt has its occasional crystalline mesa protruding out of the ground, as well as vast plains of mirror smooth salt flats, both of which are often fortified and built upon by the planes' few denizens to take advantage of the defensive benefits of such places.
> Dust is famous amongst the negative quasi-elemental planes for it's great dune filled desert, whose surface is always shifting and winding in great sinuous hills shaped by the ever present dissolving winds, which make the buildings and outposts of planar visitors and elements invariably temporary and short lived, as the effort required to keep the dust from overcoming walls or to push back the frequent assaults by Dust Bunnies could easily consume even an elven lifetime with little to show for it. With the exception of the lands of death gods, the planar fortresses, observatories and monasteries of the Doomguard and Dustmen, these deserts are inhabited almost entirely by wraiths and elemental creatures.

My issue with such elemental planes is that there is still little to differentiate the Plane of Air from an exotic* gas giant, the Plane of Earth from an exotic* crust and mantle of a terrestrial world, the Plane of Fire from an exotic* sun, and the Plane of Water from an exotic* fire planet.

After all, a sun or a planet would indeed have a well-defined boundary separating the "earth" and the "air."

There are infinite crystal spheres as per the back of the 2e Inner Planes book, so there are infinite gas giants, terrestrial worlds, suns, and water worlds as well.

*Full of elementals, elemental genies, portals, and impossible terrain, such as the great cool lakes populated by water elementals in Greyhawk's sun, Liga.

What's hard about the Basic line's planes?

The "main" plane of the setting is the ethereal plane.
It helps to think of all the inner planes as the same, with the elemental planes as different "layers".
The ethereal plane is filled with sticky compressible fog.
Movement in the ethereal plane is impossible without magic.
You can *sort of* see the prime material (et al.) from the ethereal plane.
But otherwise there's fuck all to do there.

Everything in an elemental plane is mad of that element.
The environment, the loot, the natives. Everything, even the visitors.
Turning into the elemental *does not* inherently protect the visitors from the element.
Beyond being made of less types of substances, the elemental planes essentially operate like normal diverse worlds.
>Air beats Water beats Fire beats Earth beats Air, for whatever reason.
>Air and Fire are enemies and Water and Earth are enemies. (not "Air and Earth" and "Water and Fire")
There are planets and moons and stars an everything else, spanned by vast tracts of empty space.

Special "layers" exist separately from the elemental planes where they have overlapping celestial bodies.
Natural of artificial "vortexes" lead from these "layers" to the *inside* of "wormholes" (tubes) running across the ethereal.
The tubes gradually meet up with yet more tubes and after ~10 miles the come out at one of the elemental planes.
The prime material plane is a "layer" that exists at the complete overlap of four planets (one on each elemental plane).
(2396/2000)

(cont.)
The ethereal plane is very large, but has finite size.
The outer edge can be crossed with most planar travel magic to reach the astral plane.
Everything that isn't a god or a direct act of god operates in one less dimension in the astral plane, a la. Flatland: A Romance of Many Dimensions.
Travel in the astral behaves "normally", but getting anywhere is a hassle with only two-dimensional structures. Also there's a shit ton of empty space.
Magic is usually the easiest way to cross the empty space. But with one less dimension of effect even magical travel is a pain in the ass.
"Outer planes" are any other planes (and their layers) that are connected to the astral plane. Each outer plane has it's own unique metaphysics.
The ethereal plane is essentially just another outer plane, but you call it and it's layers "inner planes" because you happen to come from there.

The neccesity for them is that if you just have "prime elemental" planes for the elements, then all the various Elemental casters get a little bit fucked, as their powers are locked into the prime as per a cleric of a god whose domain is limited exclusively to a prime world - which is a bit weird given that like Nature Casters it'd be a really primal and ubiquitous type of magic, so some planar location for the elemental casters to draw power from is needed like Arborea or the beastlands is for Nature casters to represent that fundamental aspect of elemental magic.

Now obviously you can just drop the Elemental Chaos in the place of the innerplanes, but I had some ideas rattling around my brain box for the inner planes so wrote them down so they could be used if a GM wanted.

(Note that when I type out the rules for random rolling prime worlds I'm planning of including "prime elemental" worlds in that that function like you describe, so that can be used instead too if a GM wants.)

That's what I've got up to - once I'm happy with the physical landscape of the inner planes I'll start coming up with (or mod one of the ORE random roll civilisation generators to come up with them for me) to produce a mess load of civilisation and organisations to link or cross over bits of the inner planes like the blood war, modron shenanigans, gate towns and factions do for the outerplanes, which are in many ways more important, and writing all that out has sparked a few ideas in that direction (like the plane of Ooze being a living creature in its own right and worshipped as a god by slimy prime creatures, or the fire elements kidnapping air elements for use in their torture-blimps, for example)

>Beyond being made of less types of substances, the elemental planes essentially operate like normal diverse worlds.

Huh, missed that part of that page honestly - thought it worked like in planescape where it's this hard to visualise surfaceless infinite volume - one thing they do correctly imho with most of the weirder planes like the astral is keep consistent with "the PCs experience a down and an up and can walk and aren't floating or falling or stuck inside a rock and nobody knowswhat's going on and how would you even describe this using a battlemat exactly?

Earth Plane is a planet made of earth, fire plane is planet made of fire, water plane is planet made of water, air plane... is made of air? solid air? how do?

"what does a PC see if they go to the quasi-plane of lightning with enough protection to survive there?" is a question that any "elemental planes" stuff need to answer, as well as "how am handle combat in plane?"

The second page has a (really shit) table on whats what. 3959x1733 so open it in it's own tab and zoom in if you need to
The atmosphere (where applicable) is air, the liquids are liquid forms of various gasses found in air, the solids are clouds for whatever reason.
The elemental plane of fire somehow has much more as an ass-pull write-up than that in it's column.

>then all the various Elemental casters get a little bit fucked, as their powers are locked into the prime as per a cleric of a god whose domain is limited exclusively to a prime world

This has never been the case for arcane *or* divine casters in 2e, 3.X, 4e, or 5e, so I have no idea what you are speaking of here.

Arcane casters have a crap ton of restrictions placed on them in the outer and inner planes, divine casters have problems only IF their god is one of those weird "god only of this one prime world" gods, in which case they often lose their spell slots - the rest of them get the usual "cast and use spell slots as though one effective level less for every plane between the cleric and their god's planar domain, to a maximum of -3"

>divine casters have problems only IF their god is one of those weird "god only of this one prime world" gods

I have never heard of this in AD&D 2e. Could you please cite a source?

Additionally, I fail to see why casting the elemental "planes" as all of the exotic celestial bodies spread throughout the Prime would limit elemental power to the Prime.

I'll just repost my reply to this post in /wbg/.

Well here's how I conceive of the planets, planes and universe fitting together in my D&D-based setting. It's more influenced by sourcebooks and old theories about the structure of the universe than modern science.

First, there's the Earth and it's atmosphere. Surrounding it is a void with the sun, moon and planets rotating around it. The sun provides light and warmth; the moon is the sun's opposite. They're both lifeless and they're both roughly the same size as the Earth. The planets are smaller balls of light that influence earthly affairs. Perhaps they're portals to other planes or worlds? Beyond the planets is the crystal shell of the heavens, which is covered on the inside by stars.

Once you get outside the crystal shell, you're in the elemental chaos. This is a infinite plane of the primordial protomatter like you described. Water, earth, fire, air and void all blend together here. But there are areas where one or two forms of matter clump together and create a huge, nebulous elemental plane. These elemental planes are vastly larger than any planet and are 99% homogeneous.

Floating around in the elemental chaos are other crystal spheres with other worlds inside.

>Spelljammer-esque crystal spheres
>no Phlogiston

Spelljammer misuses phlogiston in a way that makes me autistic (seriously, the phlogiston should be aether, and the plane of fire should be the plane of phlogiston if you're gonna include 18th century alchemy into shit)

A. Crystal sphere theory goes back to ancient times. That's where I stole it from, not Spelljammer.

B. Spelljammer uses phlostigon incorrectly. See: en.wikipedia.org/wiki/Phlogiston_theory

C. The Elemental Chaos works better than phlostigon in my unified theory of the planes.

Phlogiston is also several centuries too advanced a concept for the neo-platonic set up of the D&D multiverse, generally going hand in hand with sulphur and mercury and alchohol as elements on par with water and air.

So why not just use an elemental chaos?

It reads like the elemental planes are barren and boring.
What do people even do there?

>Would all suns, water worlds, and ice worlds not already be fire-, water-, or ice-attuned?
Well, yeah. Why wouldn't they be?

I don't understand how the thing you've described isn't an elemental affinity.

Among other things, an elemental affinity would influence how some spells work.

Conceptually, I mean. I know there's mechanical details, but "this place has a lot of this element and things found in it" doesn't seem that different from "this place is heavily influenced by this element".

> "this place has a lot of this element and things found in it" doesn't seem that different from "this place is heavily influenced by this element"
Saying locations have affinities to specific planes is saying "the metaphysical barriers between the planes are noticeably thinner/weaker there".
"This place has a lot of this element and things found in it" is a common side effect of that.

Perhaps we disagree on the order of cause and effect.

But if the "Elemental Plane of Fire" is not so much a new plane as it is the totality of all suns/stars and fiery areas all across the Prime (there are infinite crystal spheres and thus infinite suns/stars), then there would be no need for a specific "affinity."

Perhaps the plane is a plane but suns are actually holes in the fabric of space-time where the two planes are one?

That would mean that the Elemental Plane of Fire itself is far more dull to actually adventure in due to it being a homogenous mass of flame, as opposed to something with a "surface" like a sun.

True, but it's more of a cosmology thing than a real adventure location, and you can put pockets in it where it overlaps with other places, particularly prime, to be more habitable.

I do not think there is much of a point to a plane if it is not particularly interesting to adventure in.

>you can put pockets in it where it overlaps with other places, particularly prime, to be more habitable.
This would be called "a magical [sun/volcano/desert]," which already exists in the Prime in abundance.

Spelljammer already has various examples of fantastical suns with unusual features.

>I do not think there is much of a point to a plane if it is not particularly interesting to adventure in.

>Plane of [generic uniform quality] isn't interesting to adventure in

Well, yeah. Planes of X have always been a shit idea tbqh fampai.

>elemental chaos
That's just limbo.