The planes of existence are realms of myth and mystery. They’re not simply other worlds, but dimensions formed and governed by spiritual and elemental principles. They fall into the following categories:
Material Realms. Most D&D worlds are located on the Material Plane, which has two planar echoes: the Feywild and the Shadowfell.
Transitive Planes. The Ethereal Plane and the Astral Plane are boundless realms that provide passage between other planes of existence.
Inner Planes. The four Elemental Planes (Air, Earth, Fire, and Water), plus the Para-elemental Planes between them, are the Inner Planes.
Outer Planes. Seventeen Outer Planes correspond to the nine alignments and shades of philosophical difference between them.
Positive and Negative Planes. These two planes enfold the rest of the cosmology, providing the raw forces of life and death that underlie all existence in the multiverse.
The default D&D cosmology includes more than two dozen planes, detailed in this chapter. The most common understanding of these planes visualizes them as a group of concentric wheels, with the material realms at the center. The Inner Planes form a wheel around the Material Plane, enveloped in the Ethereal Plane. Then the Outer Planes form another wheel around and behind (or above or below) that one, arranged according to alignment, with the Outlands linking them all.
Since the primary way of traveling from plane to plane is through magical portals, the spatial relationship between different planes is largely theoretical. No being in the multiverse can look down and see the planes arranged like a diagram in a book. No mortal can verify whether Mount Celestia is sandwiched between Bytopia and Arcadia; rather, this theoretical positioning is based on the philosophical shading among the three planes and the relative importance they give to law and good.
For your campaign, you can use a different model of the planes. Here are several examples:
The Material Plane is where the philosophical and elemental forces of the other planes of existence collide in the jumbled existence of mortal life and matter. It is a thoroughly magical place, reflected in the two planes that share its central place in the multiverse.
The Feywild and the Shadowfell are parallel dimensions occupying the same cosmological space as the Material Plane. The landscapes of these three planes are similar, but those of the Feywild are more marvelous and whimsical, while those of the Shadowfell are more bleak and ominous. Passage between the Material Plane and these other realms is sometimes effortless, even accidental. Adventurers might enter a grove of trees on the Material Plane and suddenly find themselves in a lush, colorful forest on the Feywild or a grim wood of dead trees on the Shadowfell.
The Inner Planes surround the Material Plane and its echoes, providing the raw elemental substance from which all worlds were made. The four Elemental Planes—Air, Earth, Fire, and Water—form a ring around the Material Plane. The border regions between these planes are sometimes described as distinct planes in their own right: the Para-elemental Planes.
These realms exemplify the physical essence and elemental nature of air, earth, fire, and water. The entire substance of the Elemental Plane of Fire, for example, is suffused with the fundamental nature of fire: energy, passion, transformation, and destruction. Even objects of solid brass or basalt seem to dance with flame in a manifestation of the vibrancy of fire’s dominion.
At their innermost edges, where they are conceptually closest to the Material Plane, the four Elemental Planes and the four Para-elemental Planes resemble places on the Material Plane. The four elements mingle together as they do on the Material Plane, forming land, sea, and sky. But the dominant element strongly influences the environment, altering those locations’ fundamental qualities.
The inhabitants of this inner ring include aarakocra, azers, dragon turtles, gargoyles, genies, lizardfolk, mephits, salamanders, and xorn. Some originated on the Material Plane, and all can travel to the Material Plane (if they have access to the magic required) and survive there.
As the Elemental Planes extend farther from the Material Plane, they become increasingly unstable and hostile. In the outer regions, the elements exist in their purest form: great expanses of solid earth, blazing fire, crystal-clear water, and unsullied air. Any foreign substance is extremely rare; little air can be found in the outer reaches of the Plane of Earth, and earth is all but impossible to find in the outer reaches of the Plane of Fire. These areas are much less hospitable to travelers from the Material Plane than the border regions are. Such regions are little known, so one who mentions the Plane of Fire, for example, usually means the border region.
The outer regions are the domains of creatures formed of the pure elements, including air, earth, fire, and water elementals. These are also the domains of the Elemental Princes of Evil—primordial beings of pure elemental fury.
At the outermost extents of the Elemental Planes, the pure elements dissolve and bleed together into an unending tumult of clashing energies and colliding substance called the Elemental Chaos. Elementals can be found here as well, but they usually don’t stay long, preferring the comfort of their native planes.
If the Inner Planes are the raw matter and energy that make up the multiverse, the Outer Planes provide the direction, thought, and purpose for its construction. These are realms of spirituality and thought, the spheres where Celestials, Fiends, and deities dwell. The plane of Elysium, for example, isn’t merely a home for good creatures or where spirits of good creatures go when they die. It is the embodiment of goodness, a spiritual realm where evil can’t abide. It is as much a state of being and of mind as it is a physical location.
When discussing anything to do with deities and their realms, the language used must be highly metaphorical. Their actual homes aren’t literally places at all but exemplify the idea that the Outer Planes are realms of thought and spirit.
The planes with an element of good in their nature are called the Upper Planes, while those with an element of evil are the Lower Planes. A plane’s alignment (as shown in the Outer Planes table) is its essence, and a creature whose alignment doesn’t match the plane’s alignment experiences a sense of dissonance there. When a good creature visits Elysium, for example, it feels in tune with the plane, but an evil creature feels uncomfortable.
| Outer Plane | Alignment |
|---|---|
| Abyss |
Chaotic Evil |
| Acheron |
Lawful Evil, Lawful Neutral |
| Arborea |
Chaotic Good |
| Arcadia |
Lawful Good, Lawful Neutral |
| Beastlands |
Chaotic Good, Neutral Good |
| Bytopia |
Lawful Good, Neutral Good |
| Carceri |
Chaotic Evil, Neutral Evil |
| Elysium |
Neutral Good |
| Gehenna |
Lawful Evil, Neutral Evil |
| Hades |
Neutral Evil |
| Limbo |
Chaotic Neutral |
| Mechanus |
Lawful Neutral |
| Mount Celestia |
Lawful Good |
| Nine Hells |
Lawful Evil |
| Outlands |
Neutral |
| Pandemonium |
Chaotic Evil, Chaotic Neutral |
| Ysgard |
Chaotic Good, Chaotic Neutral |
The Upper Planes are the home of Celestials. The Lower Planes are the home of Fiends. The planes in between host their own unique denizens: for example, modrons are Constructs that inhabit Mechanus, and slaadi are Aberrations that thrive in Limbo.
As with the Elemental Planes, one can imagine the perceptible part of the Outer Planes as a border region, while extensive spiritual regions lie beyond ordinary sensory experience. Even in perceptible regions, appearances can be deceptive. Initially, an Outer Plane might appear hospitable and familiar to natives of the Material Plane. But the landscape can change at the whim of a deity or other powerful forces that dwell on the plane, which can remake the realm completely, erasing and rebuilding existence to better fulfill those forces’ needs.
Distance is a virtually meaningless concept on the Outer Planes. A perceptible region of a plane might seem quite small on one visit, and on another trip it can stretch on to what seems like infinity. Adventurers could take a guided tour of the Nine Hells, from the first layer to the ninth, in a single day—if the powers of the Nine Hells desire it. Or it could take weeks for travelers to make a grueling trek across a single layer.
Most Outer Planes include a number of distinct realms. These environments are often imagined as a stack of related parts of the same plane, so travelers refer to them as layers. For example, Mount Celestia resembles a sacred mountain with seven great plateaus along its ascent, the Nine Hells is like a pit where the River Styx plunges down through nine tiers, and the Abyss has a seemingly endless number of layers.
Like the planes themselves, the description of layers is highly metaphorical and subject to varying interpretations. The plane of Carceri, for example, has been described as a long series of spherical worlds arranged like beads on a string, with each sphere consisting of six nested spheres—the layers of the plane. This fanciful description is but one attempt to make sense of the distorted geography of a place that isn’t even a place in the ordinary sense of the word, but an alternate state of reality.
Most portals from elsewhere reach the first layer of a multilayered plane. This layer is depicted as the top or bottom layer, depending on the plane. As the arrival point for most visitors, the first layer functions like an antechamber for that plane.
The Outer Planes are realms of thought and morality more than merely physical reality, and they can affect visitors on a deeply personal level as well as a physical one.
At your discretion, a creature that spends a long time on an Outer Plane that is not its home plan can begin to take on aspects of that plane’s ethos. Visitors to the Upper Planes might feel strange urges to perform deeds of kindness or compassion, while visitors to the Lower Planes might find themselves drawn to acts of cruelty or betrayal. Those who spend time on Mechanus and other lawful planes might feel their ties of loyalty to each other growing stronger, while those who visit Limbo and other chaotic planes might become temporarily more independent or self-absorbed. These tendencies are best handled as DM suggestions and then roleplayed by the players, but you might award Heroic Inspiration to characters who bring these characteristics to life in their characters.
Planar Dissonance. Celestials who visit the Lower Planes and Fiends who visit the Upper Planes experience significant discomfort if their visits last more than a few hours. After finishing a Long Rest on a plane that is alien to its nature, a Celestial or Fiend makes a DC 10 Constitution saving throw. On a failed save, whenever the creature makes a D20 Test, the creature must subtract 1d4 from the roll. The effect is cumulative with each failed save and ends when the creature finishes a Long Rest on a plane that isn’t opposed to its nature.