The planes of the Dungeons & Dragons roleplaying game constitute the multiverse in which the game takes place. Each plane is a universe with its own rules with regard to gravity, geography, magic and morality. There have been various official cosmologies over the course of the different editions of the game; these cosmologies describe the structure of the standard Dungeons & Dragons multiverse.
The concept of the Inner, Ethereal, Prime Material, Astral, and Outer Planes was introduced in the earliest versions of Dungeons & Dragons; at the time there were only four Inner Planes and no set number of Outer Planes. This later evolved into what became known as the Great Wheel cosmology. The 4th Edition of the game shifted to the World Axis cosmology. The 5th Edition brought back a new version of the Great Wheel cosmology which includes aspects of World Axis model.
In addition, some Dungeons & Dragons settings have cosmologies that are very different from the "standard" ones discussed here. For example, the Eberron setting has only thirteen planes, all of which are unique to Eberron.
Publication history
The cosmology of the planes was presented for the first time, as part of the Great Wheel of Planes, in Volume 1, Number 8 of The Dragon, released July 1977. In the article "Planes: The Concepts of Spatial, Temporal and Physical Relationships in D&D", Gary Gygax mentions that there are 16 Outer Planes. The "Basic edition" of D&D had a separate, though similar, cosmology from that of its contemporary AD&D game, which is a more open planar system that is less regulated than that of its counterpart.
The planes were further "refined in the Players Handbook (1978) and Deities & Demigods (1980)". The appendix of the Player's Handbook included an abstract diagram of the planes, and mentioned the same 16 Outer Planes. Shannon Appelcline, the author of Designers & Dragons, highlighted that throughout the early 1980s Dragon magazine would continue to detail "some of the planes in more depth", however, "there was no overarching plan for the planes of D&D other than a few increasingly old drawings". The multiverse of the Basic D&D game was expanded with the D&D Immortals Rules (1986) set. The Astral Plane runs through and links the rest of the Multiverse. Plane can range in size from the tiniest Attoplane (1/3 inch long), to the Standard Plane (.085 light-years long), up to the Terraplane (851 billion light years long), with stars and planets scaled to match the size of the plane.
Both Appelcline and Curtis D. Carbonell, in his book the Dread Trident: Tabletop Role-Playing Games and the Modern Fantastic, highlighted that information on the planes and the shared cosmology was codified in the Manual of the Planes (1987) and Tales of the Outer Planes (1988). Carbonell wrote that project leader and designer Jeff Grubb detailed "the schematization of the planes' requisite five area: the Prime Material, the Ethereal, the Astral, the Inner, and the Outer planes. This basic structure is still used in 5e, with some changes that provide minor rearrangements and clarifications [...]. Grubb's approach demonstrated a need to codify, while still remaining flexible, that has remained as a primary aim of the latest edition".
Carbonell also highlighted that the 1989 Spelljammer campaign setting added cosmology that "allowed travel between the different settings" such as Dragonlance, Greyhawk, and the Forgotten Realms. However, campaign settings such as Dark Sun and Ravenloft were inaccessible in this cosmology. Then in 1993, TSR wanted to do a series of books about the Outer Planes which Zeb Cook said led to the creation of the Planescape campaign setting released in 1994. This campaign setting provided a framework to create adventures across the planes with the city of Sigil acting as a hometown and starting point for players. Carbonell called this setting "the most complex example of the multiverse created during the varieties of 2e's AD&D settings" and wrote: "A more nuanced and sophisticated attempt at harmonization, Planescape provided an alternate way to travel between the planes than Spelljammer's science-fantasy-oriented approach".
The 3rd edition Manual of the Planes (2001) detailed both the inner and outer planes. Kevin Kulp, for DMs Guild, wrote that "the authors used an approach that said 'here's how it's been done in the past, and here are other ways you can do it,' which allowed the book to avoid setting planar mechanics in stone. Instead it gave DMs a modular approach by presenting Options, a flexible strategy that pleased both 1e and Planescape fans. Vast amounts of new ideas and new locations were presented, dovetailing nicely with canon from earlier editions".
The 4th edition shifted the locations of the various planes to fit the new World Axis cosmology and added the Parallel Planes of the Feywild and the Shadowfell to the game; many of the changes were detailed in that edition's Manual of the Planes (2008). However, the 5th edition Player's Handbook (2014) and Dungeon Master's Guide (2014) shifted most of the cosmology of the planes back to the Great Wheel model with some aspects of the World Axis model retained in the descriptions of the inner planes.
Great Wheel cosmology
The cosmology outlined in the Great Wheel model contains sixteen Outer Planes which are arranged in a ring of sixteen planes with the Good-aligned planes (or Upper Planes) at the top, and the Evil-aligned planes (or Lower Planes) at the bottom. Depictions usually display the Lawful planes (or Planes of Law) to the left, and the Chaotic planes (or Planes of Chaos) to the right. Between all of these sit the Neutral planes, or the Planes of Conflict. The center contains the Inner and Material Planes.
One further plane sits in the center of the ring, the Outlands, being neutral in alignment. At the center of the Outlands is a Spire of infinite height; the city of Sigil floats above the Spire's pinnacle.
Many Outer Planes were renamed in Advanced Dungeons & Dragons 2nd Edition in the Planescape campaign setting, released in 1994. In the 3rd Edition Manual of the Planes (2001), the old and new names were combined, the Demiplane of Shadow was promoted to the Plane of Shadow, the Prime Material Plane was shortened to the Material Plane, and it was stated that each Material Plane is connected to its own unique Ethereal Plane.
The cosmology is usually presented as a series of concentric circles, with alternating spatial and transitive planes; from the center outwards, they are ordered as follows: Inner, Ethereal, Material, Astral, Outer Planes, and the Far Realm. The Shadow Plane and the Dimension of Time, if they are included, are separate from the others, and usually represented as being connected to the Material Plane. Demiplanes, although most commonly connected to the Ethereal Plane, can be found attached to any plane. All planes, save the demiplanes, are infinite in extent.
Planes may border (be coterminous) or may be coexistent. In particular, the Ethereal and Shadow planes are coexistent with the Material Plane. In effect, the "boundary" between the two extends through all of space. Thus a ghost in Dungeons & Dragons, which is an ethereal creature, has a location on the Material Plane when it is near the border of the Material and Ethereal planes. It can "manifest" itself into the Material, and force attacks launched from the Material can hit it.
Inner Planes The Inner Planes are made up of elemental matter and forces. They consist of the Elemental Planes of air, earth, fire and water, and the Energy Planes. Some descriptions also contain the Para-elemental (magma, ice, etc.) and Quasi-elemental planes (lightning, dust, etc.) linking them. The energy planes are the Positive Material Plane and Negative Material Plane.
In his review of the Planescape Campaign Setting boxed set, Gene Alloway felt that the set would provide players with a good sense of "the sheer force of nature that drives all the Inner Planes. The Inner Planes don't have anything against you—they're hard on everyone." Backstab magazine reviewers Lord Winfield and Kaneda found the Inner Planes among the places in the Planescape setting least visited by player characters, which do not lend themselves to a prolonged stay.
While the 5th Edition returned to the Great Wheel model, the Inner Planes detailed in that edition "retain aspects" of the 4th Edition World Axis model: "The four elemental planes are back, but they remain tightly integrated with the material plane as its creative foundation. The paraelemental planes have also returned for the first time since Planescape, but they have more evocative names. The Plane of Ash is known as the Great Conflagration, the Plane of Ice is the Frostfell, the Plane of Magma is the Fountains of Creation, and the Plane of Ooze is the Swamp of Oblivion. Additionally, the Elemental Chaos is the churning realm within which the Inner Planes are held". Screen Rant highlighted that the parts of the Inner Planes closest to the Material Plane will seem the most familiar to adventurers with features such as humanoid inhabitants and cities. However, the further adventurers venture "out into the Inner Planes, things become less familiar. Each plane starts to resemble its purest form, making it harder to travel without powerful magical spells that protect the party from the environment. If a traveler goes far enough, they will reach the Elemental Chaos, where the boundaries of the Inner Planes start to break down – and where some truly alien monsters exist".
Material Planes The Material Planes are worlds that balance between the philosophical forces of the Outer Planes and the physical forces of the Inner Planes—these are the standard worlds of fantasy RPG campaigns. The Prime Material Plane is where the more 'normal' worlds exist, many of which resemble Earth. The 2nd edition Dungeon Master's Guide states there are several Prime Material Planes, but several other 2nd edition products say there is only one Prime Material Plane rather than several.
Introduced in the Spelljammer setting, the Phlogiston is a part of the Material plane. It is a highly flammable gaseous medium in which crystal spheres holding various Prime Material solar systems float, traversable by Spelljammer ships.
The Feywild and the Shadowfell, the Parallel Planes introduced in the 4th Edition World Axis model, were incorporated into the 5th Edition version of the Great Wheel model. In 2015, D&D Creative Director Chris Perkins stated that 4th Edition sourcebooks on these planes were the best source of information for the 5th Edition. The adventure module The Wild Beyond the Witchlight (2021) is the first in-depth 5th Edition exploration of the Feywild and builds on the description included in the 5th Edition Dungeon Master's Guide (2014).
Outer Planes
Alignment-based planes. The home of gods, dead souls, and raw philosophy and belief.
Transitive planes The transitive planes connect the other planes and generally contain little, if any, solid matter or native life.
Astral Plane The Astral Plane is the plane of thought, memory, and psychic energy; it is where gods go when they die or are forgotten (or, most likely, both). It is a barren place with only rare bits of solid matter. The Astral Plane is unique in that it is infinitesimal instead of infinite; there is no space or time here, though both catch up with beings when they leave. The souls of the newly dead from the Prime Material Plane pass through here on their way to the afterlife or Outer Planes.
The most common feature of the Astral Plane is the silver cords of travelers using an astral projection spell. These cords are the lifelines that keep travelers of the plane from becoming lost, stretching all the way back to the traveler's point of origin.