Created as part of the latest D&D Next Blog Carnival by Rich Green.

So, the question is, how would I design the Multiverse if I were writing D&D Next?

I’d start by mashing up the Astral Sea and Spelljammer Space. They’re both great ideas, and there seems to be enough overlap between the two that I could see combining them without a big problem. Plus I love Spelljammer (Rhinomen! Guinea Pigs! Hadozee!), and would love to see it make a comeback.

So you have this massive sea-like space between worlds. Giant spaceship/galleys traverse across it, engaging in sci-fi pirate shenanigans. Maybe tie Illithids in here, add a dash of H. P. Lovecraft’s Dreamlands in for good measure. This is where Cthulhu sleeps.

I’d bring in Sigil as a central point (thematically, not literally—more on that later) in the multiverse. I think it works great for two reasons:

• It provides a contrast to the Astral Sea (a bastion of law, surrounded by the epitome of chaos)
• The City of Doors provides a faster (if no less dangerous) way to move between worlds.

All that said, I don’t think I’d lay out the Great Wheel as definitively as Planescape. The Astral Sea should be unknown, never working the same way twice, constantly changing in terms of position, orientation, distances—navigating it should require as much madness as nautical skill. You can try to master it, but it will forever attempt to devour you.

From there, I’d take an idea Greywulf pitched in a somewhat related article—Why D&D Should Be More Like Warhammer 40K. Greywulf describes creating a massive shared setting for D&D:

Let’s call such a mythical D&D setting….. oh, I dunno….. Forgotten Realms….. but it’s unlike any Forgotten Realms setting you’ve seen before. Firstly, the emphasis is on the plural. This isn’t just one Realm (populated with Dark Elf Rangers of whirling death, Elminster-dust, etc), but a whole multitude of them all linked by arcane portals and the like. One of them takes you to a cellar underneath a tavern in the city of Greyhawk. Another dumps you near an oasis in Athas, etc. The portals may indeed be forgotten and awaiting discovery, be savagely contested or open for use by all. The whole of D&D’s history is laid bare as a shared setting with your PCs able to move from one game world to another with relative ease. The Feywild and realm of Shadow may be other Realms, or something entirely different, almost portals in themselves.

I love this idea because, to put it simply, I’m a superhero nerd. I love the idea of a comic-style shared universe, and I love the idea of a proper, comic-style Multiverse even more. That’s the big reason the D&D Cosmology always bugged me—if the “Prime Material Plane” is where my campaign takes place… where does yours take place? Where does Dark Sun take place? Can I visit? This way, everything happens at once, which is awesome.

You don’t have to make it explicit, of course. Honestly, I’d probably limit “crazy portals” to Sigil. But just the idea that it’s all out there opens up possibilities. You could have the legions of Greyhawk on the hunt for a supposed strange, metal man known for his martial prowess. Maybe Athas burned because its magic isn’t the same as our magic; maybe it hails from the Illithids of the Astral Sea. Perhaps after conquering Nerath, your PCs set their sights on Sigil.

I’d take it even further. I’d take a cue from comics—and from Amazing Engine—and give PCs options for building parallel world versions of themselves, or noteworthy NPCs.

Basically, I’d want my Multiverse to feel like a Multiverse, and for PCs to feel like they’re always a part of it.

What about you? How would you build the Multiverse?