We have our raw materials all sorted, so now we start with one end of the map (I’m going with the sun) and fill in everything that’s easy and obvious. Once the obvious stuff is filled in, we can see how much we have room for left over to try and save stuff from the chopping block.
We’re going to start with the sun. And the sun is the elemental chaos. Or maybe it’s not so chaotic anymore. What’s important is that the gods use this place as a reserve of raw materials with which to create the universe (or maybe one god – I’m actually importing this idea from another setting I made with one of my brothers, where it was just the one god who did the creation, but for the sake of syncretism I’m assuming no master creator deities and instead more of an Order of the Stick approach, where lots of different pantheons had to work together to make worlds). It is surrounded by a blindingly bright wall of pure radiant energy, not fire, and past that barrier are the standard earth, fire, air, and water planes as depicted by the 5e DMG (which is only a minor update on how they were depicted in most earlier editions).
Above the sun is the city of Sigil. It’s a torus, but the city is on the inside of the torus, so when you look up from Sigil, you see more Sigil above you. The exterior of Sigil is far too hot to sustain life, constantly bombarded by the heat and pure energy of that radiant shield encircling the elemental planes. It is, however, full of astral docks. The sun, you see, is goddamn enormous, which means that if you’re at the top of it, you are actually quite high above the orbital plane. From that perch, it is easy to see the rest of the solar system (if you have good telescopes – Sigil does) and plot a course to any orbit. Sometimes it’s easy to go from one planet straight to another because they happen to be at a similar point in their orbits, but other times the two are on opposite sides of the sun – and that means regardless of where your journey starts or ends, half the time it’s somewhere between a slight detour to right along the way to stop at Sigil.
Underneath Sigil is the spire that leads up to it. It is not infinitely tall – we’re going to make a lot of things previously called “infinite” merely “unimaginably large” – but it does reach from the center of the sun up to far above its surface where Sigil lies. In the center of that spire is a space elevator leading from Sigil down to the Outlands, which you might more properly call the Inlands, since they are the center of everything. The center of the elemental chaos, connected by teleportation gate to each of the outer planes, and directly below Sigil, the trade center of the solar system.
Next up, Mercury. As mentioned earlier, there is a bizarre paucity of volcano planets for us to use for not!Mercury. Mercury could also be used as a desert planet, but we’ve already got one of those in Mars, whose dusty red landscape is better known to the public than any other planet but Earth’s. Having a pale blue dot that’s all temperate and normal with a desert planet just beyond is the bare minimum for allowing people to import knowledge of our solar system to understand the super-setting faster (and I really don’t want to demand people learn a whole new solar system from scratch – if I can keep the number of sizable moons orbiting Jupiter and Saturn the same, I’d like to, even though most people don’t have the first idea how many large-ish moons Saturn has).
Complicating matters, the one volcanic world we do have is Phyrexia, which needs to be in close proximity to its targets of invasion in Mirrodin and Dominaria, which means it needs to be a moon orbiting a gas giant so that those two planes are also moons, thus explaining why Phyrexians have targeted those two. If Phyrexia is Mercury while Mirrodin and Dominaria are orbiting Saturn, it’s super weird that Phyrexia skipped over the entire inner solar system on their way to invade not one, but two worlds. It works much better if they’re all in the same planetary neighborhood.
I’ll get to the outer planes from planescape later on, but suffice to say that I wanted them all in one place and have what I think is a pretty cool idea for them, so I don’t want to use Mercury as the Lower Planes planet with Baator and the Abyss and so on (although it’s not a completely unworkable idea – if you consider the sun’s gravity well to be the “bottom” of the solar system, Mercury is the lowest reach of the system except for the sun itself, though this is complicated somewhat with this “sun is an elemental supply depot” concept). As a side note, I also don’t want to combine Phyrexia with Baator over on Io. There’s definitely some overlap between the two, with Phyrexia even being referred to as “the Nine Hells,” but scratch the surface and Phyrexia’s got a lot of differences. They could definitely be stitched together if we didn’t have enough real estate for both of them, but again: Bizarre lack of volcano worlds leaves almost nothing to put in the Mercury slot.
I’d like to give each of the four inner planets a noticeably different climate, though – no doubling up on desert worlds, especially since Amunkhet and Dark Sun are the only desert settings to go around and neither comes close to filling up Mars by themselves. so I’m leaving Mercury blank for now. It’s a problem I’ll have to come back to and solve in the second pass. It may end up being an uninhabitable wasteland or the blasted remains of a setting I dislike. Fans of whatever setting ends up melted probably won’t approve, but if I end up going that route it’ll be using a setting I had no room for anyway, so they weren’t going to be happy to begin with.
Next, Venus. There are two routes to go with this one: Venus as tropical world on the basis that it’s closer to the sun than Earth but further than Mercury and also is colored green in the sky, and Venus as smoggy world on the basis that it’s a burning toxic hellscape in real life because the actual solar system is just no fun. We’re going with smoggy world, because giving Venus three settings is a good use of real estate, and we only have two mutually exclusive options for a tropical world: Ixalan and (sort of) Zendikar, which are separate Magic: the Gathering planes and therefore should be located on separate worlds if possible, since it’s explicitly only possible to reach one from the other with magic superpowers. Using just one (underdeveloped!) MtG world is a waste of Venus, which is nearly as big as Earth and can perfectly well host multiple different small-ish settings. Eberron, Kaladesh, the Iron Kingdoms, and DragonMech are located on Venus, which we’re calling “Eberron” as a world name. DragonMech is puny, having significant landmarks so few in number that they come across as barely the size of France, and Kaladesh is barely more than a city-state, with its major landmarks being limited to the city of Ghirapur and a handful of villages located in the prerequisite mountains, plains, swamps, forests, and islands nearby. The Iron Kingdoms can fit into a single continent, and while Eberron nominally has several continents, it doesn’t really need them to be Asia-size continents – Australia size is more than enough for many of them.
The setting of Eberron proper really only needs Khorvaire to be at all significantly large, and even that has a total of five major nations. Look at Europe on the eve of WW1 (loosely politically comparable to Eberron in tech level and the way the continent is chopped up between large empires – Eberron places its WW1 equivalent in the recent past, but that doesn’t matter because we’re comparing size, not time). Major nations include Great Britain, France, Spain, Germany, Austro-Hungary, and we now have the five nations’ worth of land needed to cover all of Khorvaire with half of Europe left to go (there is landmass in Khorvaire not occupied by these five nations, so we can say Khorvaire is about the size of Europe – one of the smaller continents).
The other continents are all very one-note and don’t need to be comparable in size to Khorvaire – maybe there’s some Mercator-style distortion going on that makes them look bigger on the maps than they are, or it’s sort of like a 16th-century map of the Americas where they just kind of slap down a bunch of extra land there because they have no idea where the coast is. Xen’drik is just a jungle wilderness like Chult or Aztlan and doesn’t need to be bigger than that, Argonessen is just a place where dragons hang out and could be the size of Australia or even New Zealand, no problem, and Sarlona gets just enough detail to maybe be worth setting up as comparable to Khorvaire in size – which makes it roughly the other half of Europe in terms of landmass. Overall, all of Eberron, the Iron Kingdoms, and DragonMech put together struggle to contribute as much landmass as Eurasia. Venus being smaller than Earth can account for some of the missing land, but overall we’re still looking at a world with a lot more ocean than Earth.
Having established that Venus!Eberron is easily big enough to hold these three, how are they changed by their proximity to one another? Firstly, those twelve moons that Eberron had are right out. That number is dropping down to zero, although it did used to have one until recently (Venus has no moon, but this planet needs a broken one for DragonMech – conveniently, there is an unproven hypothesis that Venus may have once had a moon which, due to various shenanigans, collided with the planet rather than achieving stable orbit). Additionally, in keeping with the new theme of the smog world, the air of Eberron is poisonous and tends to tint everything green. Indoor locations are almost ubiquitously full of proper air, but out of doors gas masks are required to survive longer than a few minutes. Fortunately, the air is only poisonous to breathe and can’t be absorbed through the pores. The native flora and fauna of Eberron are undeterred by the atmosphere, and can breathe and grow just fine, as can certain magically potent creatures from off-world, including dragons and the dragonmarked. Far from devoid of life, in fact, Eberron is actually warmer and more vibrantly alive than planets further out. Think less “toxic wasteland” and more the unobtainium planet from James Cameron’s Avatar. Plenty of things can breathe here – it’s just that you can’t. And also everything is tinged green like it’s the Matrix.
The Iron Kingdoms and DragonMech are both settings struggling in the wake of recent near-apocalyptic disasters. DragonMech’s region of Highpoint got hit by the moon (presumably someone needed to kill a mockingbird) which brought a bunch of lunar dragons with it. The region is now divvied up primarily between various citymechs who each roam a certain territory. Massive and massively powerful, the citymechs have Tokusatsu fights with lunar dragon kaiju. The Highpoint region is also home to many smaller mechs, “smaller” only in the sense that they can’t have entire cities built into them, and it’s shockingly common for adventurers to get their hands on one. Perhaps not so shocking, considering a mech is basically just a dungeon that is also a giant magic item, and clearing out dungeons to get magic items is basically all that adventurers do.
The Iron Kingdoms continent of Immoren is split roughly in two. Western Immoren is still a thing. Eastern Immoren didn’t do so hot after the planet got hit by the moon. While Highpoint was the actual point of impact and got all the kaiju (mostly – Toruk and Everblight did end up in Immoren), eastern Immoren was hit by shockwaves badly enough to shift some plate tectonics, annihilate local civilization, and turn the whole half of the continent into a vast, toxic desert known as the Bloodstone Marches, which are uninhabitable except to insane barbarian empires. All of Immoren is mostly a wreck, and while the western region has pulled through mostly intact, it’s still beset by constant war.
Khorvaire and its neighboring “continents” (they’re pretty pint-sized compared to proper continents, but still large enough to host multiple nations) are currently mostly at peace, although Khorvaire did recently finish up with the Last War, a war so terrifyingly destructive that surely, surely no one will ever want to fight a war ever again. The war was ended when the nation of Cyre, one of the primary belligerents, was annihilated by a mysterious presumably-weapon. This definitely had nothing to do with the moon hitting the planet, like, actually definitely didn’t, not being sarcastic, because the effect halted at the borders of Cyre and apocalyptic meteor strikes are not generally that well behaved. In any case, Cyre wasn’t simply blown up, but rather consumed by a mist with all kinds of weird (and lethal) effects. The effect does appear to be weakening over time, but the region remains uninhabitable.
With the exception of Cyre, however, Khorvaire is doing fine – and avoiding the rest of Eberron like an English professor avoiding plague cliches. Immoren is in the middle of all-out war that’s basically the Last War but in a different place, Highpoint is fighting kaiju and also possiprobably on the brink of war as soon as they run out of kaiju to keep them busy, Sarlona is in the final stages of being conquered by the empire of Riedra run by a bunch of possessing spirits with mind control powers who came from the moon, have been making periodic attempts to conquer Eberron for millennia, and may or may not be responsible for ramming the moon into the planet. And also there’s Xen’Drik, which isn’t consumed by war, but is largely untamed wilderness. Various nations of Khorvaire occasionally give it a poke and that goes better than you might think.
Kaladesh is a large island (think New Zealand) that is the prime destination on Eberron today on account of using aether regulation technology to keep the nearby air constantly purified and breathable to all visitors and also on account of not having had any recent or ongoing apocalyptic wars. Kaladesh is the driver of much of the magepunk tech of the planet, being the innovation capital of the world, and this is doubly true now that Immoren, Sarlona, and Highpoint are all on fire. Kaladesh is not without troubles, as increasing tensions between aether pirates and region’s governing body the Consulate lead to ever harsher crackdowns and stricter regulation of inventions and artifacts, but compared to the earthshattering wars and roaming kaiju, a little bit of internal unrest barely even registers.
I’m leaving some loose ends for now (and may or may not ever come back to tie them up, depending on whether I get bored of this project), specifically, dragons. Dragons feature heavily in three of the four settings we’ve Frankensteined together here, in varying ways. How do these different approaches tie together? It’s something that needs to be cleaned up before the setting is usable, but right not going to bother with that and will instead move on to not bothering with Earth.
We’re not attaching anything to Earth right now. Earth could plausibly be home to the Forgotten Realms, Pathfinder, Dragonlance, Greyhawk, Mystara, Birthright, the Lone Lands, Midgard, or Dominaria. Several of these settings are multi-continent and redundant, and are thus doubly difficult to shove onto a single planet. The point right now is to try and clear the board as much as possible specifically so that hotly contested ground like Earth will have fewer settings fighting over it when we’re done.
The moon’s light side is the Feywild and its dark side is the Shadowfell. This helps us square away a few stray planes from the standard D&D cosmology. You can also toss Lorwyn/Shadowmoor on there if you like, although rather than a switchover occurring once every 300 days, there’s just going to be a light side that’s permanently Lorwyn and a dark side that’s permanently Shadowmoor. It’s not really clear how Eventide shook out, though, so maybe this geographically bisected balance was the ultimate result. Lorwyn/Shadowmoor wasn’t actually very popular and I don’t feel obligated to include it in the first place, but it fits here pretty well anyway.
Mars is Conan d20 and Dragonlords of Melniborne. The obvious desert world to pick would be Dark Sun, but Mars is simply not nearly remote enough to make that work. Dark Sun needs to be in the far solar system, a dwarf planet past the reach of the gods, while whatever’s actually in Mars has to deal with the fact that it is actually quite accessible. If you can go from Sigil in the center of the solar system to the gas giants of the outer system without much trouble, then getting to Mars is easy. Jupiter and Saturn’s many moons need to be fairly accessible for the setting to work, so Mars is easy to get to, so it’s Hyboria (and also the Young Kingdoms). A barren red planet initially, the ancient Atlanteans began to terraform the world by melting its polar ice caps. Their civilization ended before they could finish and now all manner of successor states have arisen, dividing the world between themselves. With no central governing power, the planet remains only partially terraformed. The polar ice caps of Nordheim remain intact, and while lands like Aquilonia, Cimmeria, and Khitai have been turned green by the project, places like Shem, Stygia, and Turan remain dusty red deserts. On the other side of the planet, surrounded by water, are the archipelago of the Young Kingdoms, at their heart Melnibourne, home of Elric, last outpost of fallen Atlantis.
The Asteroid Belt is no setting in particular, but instead contains scraps of Spelljammer and basically anything else you care to include. Spelljammer’s premise is multi-system and simply cannot fit into our setting, however elements of it – like the giff and neogi – can be squeezed into asteroid colonies in the Belt. And some of these asteroids get very large. Ceres, the largest asteroid in the Belt, is bigger than Australia and large enough to be squeezed into a sphere by its own gravity rather than being all asteroid shaped. Several other asteroids, like Vesta, Pallas, and Hygieia, are nearly big enough to be pulled spherical and have a weird sort of half-spherical half-regular-asteroid shape, and are definitely big enough to be home to large nations (they’re smaller than Australia but way bigger than respectably sized nations like France or Japan), and there are countless asteroids big enough to be home to small-ish nations (i.e. Switzerland), city states, and various trade outposts, smuggler’s coves, and space hamlets. An asteroid just a few miles across can’t support a whole nation, but if its land is arable (and we’re sailing to Mars in a space galleon, so why not?) it can support a small population. In addition to the neogi slaver fleets, dwarven citadels, and mind flayer enclaves, the asteroid belt contains unnumbered and innumerable asteroids big enough to support towns and cities which can be used for whatever. There’s literally a million asteroids, GMs can fill them in all day and we’ll never run out.