Snarf Zagyg
Notorious Liquefactionist
Good artists borrow, great artists steal.
I was looking at the following conversations in these two threads about the multiverse in D&D, and how that certain Card Game's setting can be incorporated into the D&D multiverse, and, for that matter, how the multiple D&D settings that we are seeing now (and have been used in the past) can be reconciled with each other.
All of which made me think about the origins of the D&D multiverse; specifically, why a return to the old Gygaxian multiverse should solve all of the problems. First, a history lesson.
A. The Proto-history of the Gygaxian Multiverse.
D&D's multiverse first started in the campaigns being run by Gary Gygax, but the first print version that I am aware of is Dragon #8 (July, 1977), which gave us the first glimpse of the extra-planar nature of the D&D multiverse. It's the beginning of D&D cosmology that we later see expanded on. But the most important things to note are these brief notes:
For game purposes the DM is to assume the existence of an infinite number of co-existing planes. The normal plane for human-type life forms is the Prime Material Plane.
There are seven inner planes. The first (no. 1) is the Prime Material. The planet Earth and everything on it, all of the solar systems and the whole universe are of the Prime Material. The Fantasy worlds you create belong to the Prime Material.
The reason this is important is that it is, as far as I know, the first written acknowledgement that the Prime Material Plane is legion; it contains not just an infinite set of planes, but a really big infinite set (something something aleph). While most histories of the D&D multiverse then concentrate on the evolution of the various inner and outer planes, it is really this idea of the Prime Material used by Gygax that is so intriguing and worth developing, IMO.
EDIT- also, please see this post by @Alzrius.
B. The Core Rule Rule Books.
The Gygaxian multiverse was then slightly expanded and codified in the AD&D Player's Handbook (1978). Of importance we see the following:
There exist an infinite number of parallel universes and planes of existence in the fantastic "multiverse" of ADVANCED DUNGEONS & DRAGONS. ... The Prime Material Plane (or Physical Plane) houses the universe and all of its parallels. It is the plane of Terra, and your campaign, in all likelihood. ... The Ethereal Plane is that which surrounds and touches all of the other Inner Planes, the endless parallel worlds of the universe, without being a part of any of them. (PHB 120).
Later, the Dungeon Master's Guide (1979) was more explicit. The section "TRAVEL IN THE KNOWN PLANES OF EXISTENCE" states the following:
The Known Planes of Existence, as depicted in APPENDIX IV of the PLAYERS HANDBOOK, offer nearly endless possibilities for ADBD play, although some of these new realms will no longer be fantasy as found in swords & sorcery or myth but verge an that of science fiction, horror, or lust about anything else desired. How so? The known planes are a part of the "multiverse". In the Prime Material Plane are countless suns, planets, galaxies, universes. So too there are endless parallel worlds. (DMG 57).
Later, the DMG explicitly states that alternate planes in the Primae Material do exist, and states that the use of other game systems (such as Boot Hill & Gamma World) can be used. There is even the concept that some planes would allow for breathable atmospheres between the "main planet" and the other planets and moons - shades of Spelljammer!
Later on, the DMG makes it explicit, with conversion tables to allow characters to go back and forth between D&D, Boot Hill, and Gamma World, and explicitly states that all possibilities of adventure are contained within the planes of the Prime Material.
Similarly, there are places where adventurers can journey to a land of pure Greek mythology, into the future where the island of King Kong awaits their pleasure, or through the multiverse to different planets, including Jack Vance’s “Planet of Adventure”, where they hunt sequins in the Carabas while Dirdir and Dirdirmen hunt them. (DMG 112).
C. The Modules & Early Play.
Of course, there was also a rich history of these alternate planes existing in the modules. The go-to example for most people is Q1 (previewed in D3); who can forget that Web Level 4 has teleportation devices to multiple alternate worlds on the prime material plane! The Pharisee - evil elves of Caer Sidi. The Nightmare World of Vald Tolenkov (the proto-Strahd). The last kingdom of the mountain dwarves. And so on.
But they exist in so many modules! Castle Amber has a large proto-plane. EX1 and EX2 (Alice). Simply put, there was a general and acknowledged existence of many planes of existence, of many realities, that were considered standard in earlier D&D. All campaigns, all games, from this Earth to Greyhawk to Star Frontiers to all possible home campaigns exist within the Prime Material plane. And this is in accord with what we know from early play in Gygax's campaign. While the examples are multitudinous, we can look at an example from this website:
www.enworld.org
D. Where did the Infinite Planes of the Prime Material Come From?
There is obviously a general 60s and early 70s gestalt that would seem to permeate the idea of infinite planes. But the idea of infinite, slightly different planes on the prime material, and the specific way that you travel between them using the ethereal plane .... while it borrows a little from all sorts of sources, and while it certainly is in line with the general gestalt, I think you can trace the idea to one very specific source.
June, 1970, was the publication date of Nine Princes in Amber by Roger Zelazny (the author is, of course, name-checked in Appendix N). The primary conceit of the series is that there are an infinite number of "shadow worlds" that the protagonist, Corwin, and certain others can move through, and each is slightly different than the other. There are an infinite number of alternate histories, of worlds, of possibilities, of creatures. While this may not have been the sole source (and certainly not for the outer planes) it certainly seems that it played on outsize role in crystallizing some of the concepts for the Prime Material.
....and why does this matter?
Sometime between the publication of the Manual of the Planes (1987) and Planescape (1994), we were seeing a seismic shift in the focus of the D&D multiverse. This is my general belief; outer planes ... well, they seem cool, right? Why not futz about with the outer planes? Why not populate them, and make them interesting? Why not try and make them focal points of adventure? They are weird, and exotic, and an interesting design space.
But in my opinion, that missed the original brilliance of the Prime Material. The Prime Material is, quite literally, everything you could ever imagine. It is all worlds. Ever. It is your friend, Bob's, OD&D Monty Haul campaign. It is the d20 modern world. It is the 4e Gamma World. It is the homebrew Rakshasa world. It is Star Frontiers, but with Kender instead of Sathar. It is our planet, right now, as well as both versions of Battlestar Galactica.
It is Greyhawk with a breathable space, a Greyhawk with a not-breathable space, and a Greyhawk in a Spelljammer space. All the campaign settings that have been printed, or can be printed, or can even be imagined, are already within the Prime Material.
So, in a certain sense, there is never a need to worry about how something "fits into" the D&D multiverse.
Because everything is already in the D&D multiverse and always has been.
I was looking at the following conversations in these two threads about the multiverse in D&D, and how that certain Card Game's setting can be incorporated into the D&D multiverse, and, for that matter, how the multiple D&D settings that we are seeing now (and have been used in the past) can be reconciled with each other.
All of which made me think about the origins of the D&D multiverse; specifically, why a return to the old Gygaxian multiverse should solve all of the problems. First, a history lesson.
A. The Proto-history of the Gygaxian Multiverse.
D&D's multiverse first started in the campaigns being run by Gary Gygax, but the first print version that I am aware of is Dragon #8 (July, 1977), which gave us the first glimpse of the extra-planar nature of the D&D multiverse. It's the beginning of D&D cosmology that we later see expanded on. But the most important things to note are these brief notes:
For game purposes the DM is to assume the existence of an infinite number of co-existing planes. The normal plane for human-type life forms is the Prime Material Plane.
There are seven inner planes. The first (no. 1) is the Prime Material. The planet Earth and everything on it, all of the solar systems and the whole universe are of the Prime Material. The Fantasy worlds you create belong to the Prime Material.
The reason this is important is that it is, as far as I know, the first written acknowledgement that the Prime Material Plane is legion; it contains not just an infinite set of planes, but a really big infinite set (something something aleph). While most histories of the D&D multiverse then concentrate on the evolution of the various inner and outer planes, it is really this idea of the Prime Material used by Gygax that is so intriguing and worth developing, IMO.
EDIT- also, please see this post by @Alzrius.
B. The Core Rule Rule Books.
The Gygaxian multiverse was then slightly expanded and codified in the AD&D Player's Handbook (1978). Of importance we see the following:
There exist an infinite number of parallel universes and planes of existence in the fantastic "multiverse" of ADVANCED DUNGEONS & DRAGONS. ... The Prime Material Plane (or Physical Plane) houses the universe and all of its parallels. It is the plane of Terra, and your campaign, in all likelihood. ... The Ethereal Plane is that which surrounds and touches all of the other Inner Planes, the endless parallel worlds of the universe, without being a part of any of them. (PHB 120).
Later, the Dungeon Master's Guide (1979) was more explicit. The section "TRAVEL IN THE KNOWN PLANES OF EXISTENCE" states the following:
The Known Planes of Existence, as depicted in APPENDIX IV of the PLAYERS HANDBOOK, offer nearly endless possibilities for ADBD play, although some of these new realms will no longer be fantasy as found in swords & sorcery or myth but verge an that of science fiction, horror, or lust about anything else desired. How so? The known planes are a part of the "multiverse". In the Prime Material Plane are countless suns, planets, galaxies, universes. So too there are endless parallel worlds. (DMG 57).
Later, the DMG explicitly states that alternate planes in the Primae Material do exist, and states that the use of other game systems (such as Boot Hill & Gamma World) can be used. There is even the concept that some planes would allow for breathable atmospheres between the "main planet" and the other planets and moons - shades of Spelljammer!
Later on, the DMG makes it explicit, with conversion tables to allow characters to go back and forth between D&D, Boot Hill, and Gamma World, and explicitly states that all possibilities of adventure are contained within the planes of the Prime Material.
Similarly, there are places where adventurers can journey to a land of pure Greek mythology, into the future where the island of King Kong awaits their pleasure, or through the multiverse to different planets, including Jack Vance’s “Planet of Adventure”, where they hunt sequins in the Carabas while Dirdir and Dirdirmen hunt them. (DMG 112).
C. The Modules & Early Play.
Of course, there was also a rich history of these alternate planes existing in the modules. The go-to example for most people is Q1 (previewed in D3); who can forget that Web Level 4 has teleportation devices to multiple alternate worlds on the prime material plane! The Pharisee - evil elves of Caer Sidi. The Nightmare World of Vald Tolenkov (the proto-Strahd). The last kingdom of the mountain dwarves. And so on.
But they exist in so many modules! Castle Amber has a large proto-plane. EX1 and EX2 (Alice). Simply put, there was a general and acknowledged existence of many planes of existence, of many realities, that were considered standard in earlier D&D. All campaigns, all games, from this Earth to Greyhawk to Star Frontiers to all possible home campaigns exist within the Prime Material plane. And this is in accord with what we know from early play in Gygax's campaign. While the examples are multitudinous, we can look at an example from this website:
James M Ward: Meeting Gary Gygax and Learning D&D
Thank you all for the very kind welcome onto the EN World pages. A writer always glories in the kind words of his readers. Also I want you to know I will be very responsive to the interests of the EN World group. From the notes already left for me [in the first article, Who In The World is James...

Isle of the Ape, Alice in Wonderland, Boot Hill. The borders of the planes were porous indeed, in 1974.Into the dungeon we boldly walked. The others were old hands and had hand drawn maps of several levels. Mapping looked like a lot of fun. Brian Blume taught me how to trail map so I was recording our turnings as Gary called out the distances. We went into a new section of the dungeon and suddenly everyone in the group was tense and I had no idea why.
“You come upon three doors and each one is a bit strange,” Gary described. “The left one has the picture of an island in the middle of the door (it was the Isle of the Ape in playtest). The middle door has the picture of a walrus on a beach. The right one has a picture of an odd looking humanoid with a strange cap and in its hand is a strange crossbow pistol.”
I wasn't about to say anything. The group chose the door with the island image. We walked through and found ourselves at night with an ocean breeze coming from the west. We moved by moon light and decided not to mark our presence with a torch or lantern. Gary perfectly described the hilly area. We came to a village with no one moving about. I couldn't see anything in the window of the large hut I was looking at so I cast my light spell into the hut. BIG MISTAKE! It seems I woke up ten warrior natives. The magic spooked them and they grabbed their spears and ran for the door.
D. Where did the Infinite Planes of the Prime Material Come From?
There is obviously a general 60s and early 70s gestalt that would seem to permeate the idea of infinite planes. But the idea of infinite, slightly different planes on the prime material, and the specific way that you travel between them using the ethereal plane .... while it borrows a little from all sorts of sources, and while it certainly is in line with the general gestalt, I think you can trace the idea to one very specific source.
June, 1970, was the publication date of Nine Princes in Amber by Roger Zelazny (the author is, of course, name-checked in Appendix N). The primary conceit of the series is that there are an infinite number of "shadow worlds" that the protagonist, Corwin, and certain others can move through, and each is slightly different than the other. There are an infinite number of alternate histories, of worlds, of possibilities, of creatures. While this may not have been the sole source (and certainly not for the outer planes) it certainly seems that it played on outsize role in crystallizing some of the concepts for the Prime Material.
....and why does this matter?
Sometime between the publication of the Manual of the Planes (1987) and Planescape (1994), we were seeing a seismic shift in the focus of the D&D multiverse. This is my general belief; outer planes ... well, they seem cool, right? Why not futz about with the outer planes? Why not populate them, and make them interesting? Why not try and make them focal points of adventure? They are weird, and exotic, and an interesting design space.
But in my opinion, that missed the original brilliance of the Prime Material. The Prime Material is, quite literally, everything you could ever imagine. It is all worlds. Ever. It is your friend, Bob's, OD&D Monty Haul campaign. It is the d20 modern world. It is the 4e Gamma World. It is the homebrew Rakshasa world. It is Star Frontiers, but with Kender instead of Sathar. It is our planet, right now, as well as both versions of Battlestar Galactica.
It is Greyhawk with a breathable space, a Greyhawk with a not-breathable space, and a Greyhawk in a Spelljammer space. All the campaign settings that have been printed, or can be printed, or can even be imagined, are already within the Prime Material.
So, in a certain sense, there is never a need to worry about how something "fits into" the D&D multiverse.
Because everything is already in the D&D multiverse and always has been.
Last edited: