Creating a Multiverse

When Adventurers reach higher levels their path extends to other dimensions of reality: the planes of existence that form the multiverse. The characters might be called on to rescue a friend from the horrific depths of the Abyss or to sail the shining waters of the River Oceanus. They can hoist a tankard with the friendly giants of Ysgard or face the chaos of Limbo to contact a wizened githzerai sage.

Planes of existence define the extremes of strange and often dangerous environments. The most bizarre locations present settings undreamed of in the natural world. Planar adventures offer unprecedented dangers and wonders. Adventurers walk on streets made of solid fire, or test their mettle on a battlefield where the fallen are resurrected with each dawn.

The Planes

The various 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.

The Outer Planes are realms of spirituality and thought. They are the spheres where celestials, fiends, and deities exist. The plane of Elysium, for example, isn’t merely a place where good creatures dwell, and not even simply the place where spirits of good creatures go when they die. It is the plane of goodness, a spiritual realm where evil can’t flourish. It is as much a state of being and of mind as it is a physical location.

The Inner Planes exemplify the physical essence and elemental nature of air, earth, fire, and water. The Elemental Plane of Fire, for example, embodies the essence of fire. The plane’s entire substance 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 visible and palpable manifestation of the vibrancy of fire’s dominion.

In this context, the Material Plane is the nexus where all these philosophical and elemental forces collide in the jumbled existence of mortal life and matter. The worlds of D&D exist within the Material Plane, making it the starting point for most campaigns and adventures.

The rest of the multiverse is defined in relation to the Material Plane.

Planar Categories

The planes of the default D&D cosmology are grouped in the following categories:

The Material Plane and Its Echoes. The Feywild and the Shadowfell are reflections of the Material Plane.

The Transitive Planes. The Ethereal Plane and the Astral Plane are mostly featureless planes that serve primarily as pathways to travel from one plane to another.

The Inner Planes. The four Elemental Planes (Air, Earth, Fire, and Water), plus the Elemental Chaos that surrounds them, are the Inner Planes.

The Outer Planes. Sixteen Outer Planes correspond to the eight non-neutral alignments and shades of philosophical difference between them.

The Positive and Negative Planes. These two planes enfold the rest of the cosmology, providing the raw forces of life and death that underlie the rest of existence in the multiverse.

Putting the Planes Together

As described in the Player’s Handbook, the assumed D&D cosmology includes more than two dozen planes. For your campaign, you decide what planes to include, inspired by the standard planes, drawn from Earth’s myths, or created by your own imagination.

At minimum, most D&D campaigns require these elements:

• A plane of origin for fiends
• A plane of origin for celestials
• A plane of origin for elementals
• A place for deities, which might include any or all of the previous three
• The place where mortal spirits go after death, which might include any or all of the first three
• A way of getting from one plane to another
• A way for spells and monsters that use the Astral Plane and the Ethereal Plane to function

Once you’ve decided on the planes you want to use in your campaign, putting them into a coherent cosmology is an optional step. Since the primary way of traveling from plane to plane, even using the Transitive Planes, is through magical portals that link planes together, the exact relationship of different planes to one another is largely a theoretical concern. No being in the multiverse can look down and see the planes in their arrangement the same way as we look at a diagram in a book. No mortal can verify whether Mount Celestia is sandwiched between Bytopia and Arcadia, but it’s a convenient theoretical construct based on the philosophical shading among the three planes and the relative importance they give to law and good.

Sages have constructed a few such theoretical models to make sense of the jumble of planes, particularly the Outer Planes. The three most common are the Great Wheel, the World Tree, and the World Axis, but you can create or adapt whatever model works best for the planes you want to use in your game.

Inventing Your Own Planes

Each of the planes described in this chapter has at least one significant effect on travelers who venture there. When you design your own planes, it’s a good idea to stick to that model. Create one simple trait that players notice, that doesn’t create too much complication at the gaming table, and that’s easy to remember. Try to reflect the philosophy and mood of the place, not merely its physical characteristics.

The Great Wheel

The default cosmological arrangement presented in the Player’s Handbook visualizes the planes as a group of concentric wheels, with the Material Plane and its echoes 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.

This arrangement makes sense of the way the River Styx flows among the Lower Planes, connecting Acheron, the Nine Hells, Gehenna, Hades, Carceri, the Abyss, and Pandemonium like beads on a string. But it’s not the only possible explanation of the river’s course.

The World Tree

A different arrangement of planes envisions them situated among the roots and branches of a great cosmic tree, literally or figuratively.

For example, the Norse cosmology centers on the World Tree Yggdrasil. The three roots of the World Tree touch the three realms: Asgard (an Outer Plane that includes Valhalla, Vanaheim, Alfheim, and other regions), Midgard (the Material Plane), and Niflheim (the underworld). The Bifrost, the rainbow bridge, is a unique transitive plane that connects Asgard and Midgard.

Similarly, one vision of the planes where the deities of the Forgotten Realms reside situates a number of celestial planes in the branches of a World Tree, while the fiendish planes are linked by a River of Blood. Neutral planes stand apart from them. Each of these planes is primarily the domain of one or more deities, though they are also the homes of celestial and fiendish creatures.

The World Axis

In this view of the cosmos, the Material Plane and its echoes stand between two opposing realms. The Astral Plane (or Astral Sea) floats above them, holding any number of divine domains (the Outer Planes). Below the Material Plane is the Elemental Chaos, a single, undifferentiated elemental plane where all the elements clash together. At the bottom of the Elemental Chaos is the Abyss, like a hole torn in the fabric of the cosmos.

Other Visions

As you build your own cosmology, consider the following alternatives.

The Omniverse

This simple cosmology covers the bare minimum: a Material Plane; the Transitive Planes; a single Elemental Chaos; an Overheaven, where good-aligned deities and celestials live; and the Underworld, where evil deities and fiends live.

Myriad Planes

In this cosmology, countless planes clump together like soap bubbles, intersecting with each other more or less at random.

The Orrery

All the Inner and Outer Planes orbit the Material Plane, exerting greater or lesser influence on the world as they come nearer and farther. The world of Eberron uses this cosmological model.

The Winding Road

In this cosmology, every plane is a stop along an infinite road. Each plane is adjacent to two others, but there’s no necessary cohesion between adjacent planes; a traveler can walk from the slopes of Mount Celestia onto the slopes of Gehenna.

Mount Olympus

In the Greek cosmology, Mount Olympus stands at the center of the world (the Material Plane), with its peak so high that it’s actually another plane of existence: Olympus, the home of the gods. All the Greek gods except Hades have their own domains within Olympus. In Hades, named for its ruler, mortal souls linger as insubstantial shades until they eventually fade into nothing. Tartarus, where the titans are imprisoned in endless darkness, lies below Hades. And far to the west of the known world in the Material Plane are the blessed Elysian Fields. The souls of great heroes reside there.

Solar Barge

The Egyptian cosmology is defined by the daily path of the sun-across the sky of the Material Plane, down to the fair Offering Fields in the west, where the souls of the righteous live in eternal reward, and then beneath the world through the nightmarish Twelve Hours of Night. The Solar Barge is a tiny Outer Plane in its own right, though it exists within the Astral Plane and the other Outer Planes in the different stages of its journey.

One World

In this model, there are no other planes of existence, but the Material Plane includes places like the bottomless Abyss, the shining Mount Celestia, the strange city of Mechanus, the fortress of Acheron, and so on. All the planes are locations in the world, reachable by ordinary means of travel-though extraordinary effort is required, for example, to sail across the sea to the blessed isles of Elysium.

The Otherworld

In this model, the Material Plane has a twin realm that fills the role of all the other planes. Much like the Feywild, it overlays the Material Plane and can be reached through thin places where the worlds are particularly close: through caves, by sailing far across the sea, or in fairy rings in remote forests. It has dark, evil regions (homes of fiends and evil gods), sacred isles (homes of celestials and the spirits of the blessed death), and realms of elemental fury. This otherworld is sometimes overseen by an eternal city, or by four cities that each represent a different aspect of reality. The Celtic cosmology has an otherworld, called Tir na nug, and the cosmologies of some religions inspired by Asian myth have a similar Spirit World.

Planar Travel

When adventurers travel to other planes of existence, they undertake a legendary journey that might force them to face supernatural guardians and undergo various ordeals. The nature of that journey and the trials along the way depend in part on the means of travel, and whether the adventurers find a magic portal or use a spell to carry them.

Planar Portals

[Raistlin’s] eyes studied the Portal, studied every detail intently-although it was not really necessary. He had seen it myriad times in dreams both sleeping and waking. The spells to open it were simple, nothing elaborate or complex.

Each of the five dragon heads surrounding and guarding the Portal must be propitiated with the correct phrase. Each must be spoken to in the proper order. But, once that was done and the White Robed Cleric had exhorted Paladine to intercede and hold the Portal open, they would enter. It would close behind them.

And he would face his greatest challenge.

• Margaret Weis and Tracy Hickman

“Portal” is a general term for a stationary interplanar connection that links a specific location on one plane to a specific location on another. Some portals function like doorways, appearing as a clear window or a fog-shrouded passage, and interplanar travel is as simple as stepping through the doorway. Other portals are locations-circles of standing stones, soaring towers, sailing ships, or even whole towns-that exist in multiple planes at once or flicker from one plane to another. Some are vortices, joining an Elemental Plane with a very similar location on the Material Plane, such as the heart of a volcano (leading to the Plane of Fire) or the depths of the ocean (to the Plane of Water).

Passing through a planar portal can be the simplest way to travel from the Material Plane to a desired location on another plane. Most of the time, though, a portal presents an adventure in itself.

First, the adventurers must find a portal that leads where they want to go. Most portals exist in distant locations, and a portal’s location often has thematic similarities to the plane it leads to. For example, a portal to the heavenly mountain of Celestia might be located on a mountain peak.

Second, portals often have guardians charged with ensuring that undesirable people don’t pass through. Depending on the portal’s destination, “undesirable people” might include evil characters, good characters, cowards, thieves, anyone wearing a robe, or any mortal creature. A portal’s guardian is typically a powerful magical creature, such as a genie, sphinx, titan, or native of the portal’s destination plane.

Finally, most portals don’t stand open all the time, but open only in particular situations or when a certain requirement is met. A portal can have any conceivable requirement, but the following are the most common:

• Time. The portal functions only at particular times: during a full moon on the Material Plane, or every ten days, or when the stars are in a particular position. Once it opens, such a portal remains open for a limited time, such as for three days following the full moon, or for an hour, or for 1d4 + 1 rounds.
• Situation. The portal functions only if a particular condition is met. A situation-keyed portal opens on a clear night, or when it rains, or when a certain spell is cast in its vicinity.
• Random. A random portal functions for a random period, then shuts down for a similarly random duration. Typically, such a portal allows 1d6 + 6 travelers to pass through, then shuts down for 1d6 days.
• Command Word. The portal functions only if a particular command word is spoken. Sometimes the word must be spoken as a character passes through the portal (which is otherwise a mundane doorway, window, or similar opening). Other portals open when the command word is spoken and remain open for a short time.
• Key. The portal functions if the traveler is holding a particular object; the item acts much like a key to a door. This key item can be a common object or a particular key created for that portal. The city of Sigil above the Outlands is known as the City of Doors because it features an overwhelming number of such item-keyed portals.

Learning and meeting a portal’s requirements can draw characters into further adventures as they chase down a key item, scour old libraries for command words, or consult sages to find the right time to visit the portal.

Spells

Sarya raised her hands and began to declaim the words of a very powerful spell, one of the most dangerous she knew, a spell designed to breach the barriers between the planes and create a magical bridge into another realm of existence. The mythal thrummed in response, the intangible pulse of the old device taking on a new and different note. Sarya ignored the mythal stone’s change and pressed on, finishing her gate spell with skill and confidence.

“The gate is open!” she cried. “Malkizid, come forth!”

Before Sarya a great ring or hoop of golden magic coalesced from the air. Through it she glimpsed the realm of Malkizid, an infernal wasteland of parched desert, windswept rifts, and black, angry skies torn by crimson lightning. Then, through the gate, the archdevil Malkizid appeared. With one smooth step he crossed from his infernal plane into the mythal chamber.

• Richard Baker

A number of spells allow direct or indirect access to other planes of existence. Plane shift and gate can directly transport adventurers to any other plane, with different degrees of precision. Etherealness allows adventurers to enter the Ethereal Plane. And the astral projection spell lets adventurers project themselves into the Astral Plane and from there travel to the Outer Planes.

Plane Shift

The plane shift spell has two important limitations. The first is the material component: a small, forked, metal rod (like a tuning fork) attuned to the desired planar destination. The spell requires the proper resonating frequency to home in on the correct location, and the fork must be made of the right material (sometimes a complex alloy) to focus the spell’s magic properly. Crafting the fork is expensive (at least 250 gp), but even the act of researching the correct specifications can lead to adventure. After all, not many people voluntarily travel into the depths of Carceri, so very few know what kind of tuning fork is required to get there.

Second, the spell doesn’t send the caster to a specific location unless he or she has specialized information. The sigil sequence of a teleportation circle located on another plane allows the caster to travel directly to that circle, but such knowledge is even harder to come by than the specifications of the required tuning fork. Otherwise, the spell transports the caster to a location in the general vicinity of the desired spot. Wherever the adventurers arrive, they’ll most likely still need to undertake a journey to reach the object of a planar quest.

Gate

The gate spell opens a portal linked to a specific point on another plane of existence. The spell provides a shortcut to a planar destination, bypassing many of the guardians and trials that would normally fill such a journey. But this 9th-level spell is out of reach for all but the most powerful characters, and it does nothing to negate any obstacles that wait at the destination.

The gate spell is powerful, but not infallible. A deity, demon lord, or other powerful entity can prevent such a portal from opening within its dominion.

Astral Plane

Halisstra opened her eyes and found herself drifting in an endless silver sea. Soft gray clouds moved slowly in the distance, while strange dark streaks twisted violently through the sky, anchored in ends so distant she couldn’t perceive them, their middle parts revolving angrily like pieces of string rolled between a child’s fingertips. She glanced down, wondering what supported her, and saw nothing but more of the strange pearly sky beneath her feet and all around her.

She drew in a sudden breath, surprised by the sight, and felt her lungs fill with something sweeter and perhaps a little more solid than air, but instead of gagging or drowning on the stuff she seemed perfectly acclimated to it. An electric thrill raced through her limbs as she found herself mesmerized by the simple act of respiration.

• Richard Baker

The Astral Plane is the realm of thought and dream, where visitors travel as disembodied souls to reach the Outer Planes. It is a great silvery sea, the same above and below, with swirling wisps of white and gray streaking among motes of light like distant stars. Most of the Astral Sea is a vast, empty expanse. Visitors occasionally stumble upon the petrified corpse of a dead god or other chunks of rock drifting forever in the silvery void. Much more commonplace are color pools—magical pools of colored light that flicker like radiant, spinning coins.

Creatures on the Astral Plane don’t age or suffer from hunger or thirst. For this reason, humanoids that live on the Astral Plane (such as the githyanki) establish outposts on other planes, often the Material Plane, so their children can grow to maturity.

A traveler in the Astral Plane can move by simply thinking about moving, but distance has little meaning. In combat, though, a creature’s walking speed (in feet) is equal to 3 × its Intelligence score. The smarter a creature is, the easier it can control its movement by act of will.

Astral Projection

Traveling through the Astral Plane by means of the astral projection spell involves projecting one’s consciousness there, usually in search of a gateway to an Outer Plane to visit. Since the Outer Planes are as much spiritual states of being as they are physical places, this allows a character to manifest in an Outer Plane as if he or she had physically traveled there, but as in a dream.

A character’s death-either in the Astral Plane or on the destination plane-causes no actual harm. Only the severing of a character’s silver cord while on the Astral Plane (or the death of his or her helpless physical body on the Material Plane) can result in the character’s true death. Thus, high-level characters sometimes travel to the Outer Planes by way of astral projection rather than seek out a portal or use a more direct spell.

Only a few things can sever a traveler’s silver cord, the most common being a psychic wind (described below). The legendary silver swords of the githyanki also have this ability. A character who travels bodily to the Astral Plane (by means of the plane shift spell or one of the rare portals that leads directly there) has no silver cord.

Color Pools

Gateways leading from the Astral Plane to other planes appear as two-dimensional pools of rippling colors, 1d6 × 10 feet in diameter. Traveling to another plane requires locating a color pool that leads to the desired plane. These gateways to other planes can be identified by color, as shown on the Astral Color Pools table. Finding the right color pool is a matter of chance: locating the correct one takes 1d4 × 10 hours of travel.

Astral Color Pools

Psychic Wind

A psychic wind isn’t a physical wind like that found on the Material Plane, but a storm of thought that batters travelers' minds rather than their bodies. A psychic wind is made up of lost memories, forgotten ideas, minor musings, and subconscious fears that went astray in the Astral Plane and conglomerated into this powerful force.

A psychic wind is first sensed as a rapid darkening of the silver-gray sky. After a few rounds, the area becomes as dark as a moonless night. As the sky darkens, the traveler feels buffeting and shaking, as if the plane itself was rebelling against the storm. As quickly as it comes, the psychic wind passes, and the sky returns to normal in a few rounds.

The psychic wind has two kinds of effects: a location effect and a mental effect. A group of travelers journeying together suffers the same location effect.

Each traveler affected by the wind must also make a DC 15 Intelligence saving throw. On a failed save, the traveler suffers the mental effect as well. Roll a d20 twice and consult the Psychic Wind Effects tables to determine the location and mental effects.

Psychic Wind

Psychic Wind Effects

Astral Plane Encounters

Planar travelers and refugees from other planes wander the expanses of the Astral Plane. The most prominent denizens of the Astral Plane are the githyanki, an outcast race of reavers that sail sleek astral ships, slaughter astral travelers, and raid planes touched by the Astral. Their city, Tu’narath, floats through the Astral Plane on a chunk of rock that is actually the body of a dead god. Celestials, fiends, and mortal explorers often scour the Astral Plane for color pools leading to desired destinations. Characters who linger for too long in the Astral might have an encounter with one or more wandering angels, demons, devils, night hags, yugoloths, or other planar travelers.

Ethereal Plane

Tamlin felt a hand on him, felt his body shimmer into mist. The screams and shouts sounded far off. The walls around him appeared to be only gray shadows. Rivalen and Brennus stood beside him. “The ethereal plane,” Rivalen said. “The dragon’s breath cannot affect us here.”

• Paul S. Kemp

The Ethereal Plane is a misty, fog-bound dimension. Its “shores,” called the Border Ethereal, overlap the Material Plane and the Inner Planes, so that every location on those planes has a corresponding location on the Ethereal Plane. Visibility in the Border Ethereal is limited to 60 feet. The plane’s depths comprise a region of swirling mist and fog called the Deep Ethereal, where visibility is limited to 30 feet.

Characters can use the etherealness spell to enter the Border Ethereal. The plane shift spell allows transport to the Border Ethereal or the Deep Ethereal, but unless the intended destination is a specific location or a teleportation circle, the point of arrival could be anywhere on the plane.

Border Ethereal

From the Border Ethereal, a traveler can see into whatever plane it overlaps, but that plane appears muted and indistinct, its colors blurring into each other and its edges turning fuzzy. Ethereal denizens watch the plane as though peering through distorted and frosted glass, and can’t see anything beyond 30 feet into the other plane. Conversely, the Ethereal Plane is usually invisible to those on the overlapped planes, except with the aid of magic.

Normally, creatures in the Border Ethereal can’t attack creatures on the overlapped plane, and vice versa. A traveler on the Ethereal Plane is invisible and utterly silent to someone on the overlapped plane, and solid objects on the overlapped plane don’t hamper the movement of a creature in the Border Ethereal. The exceptions are certain magical effects (including anything made of magical force) and living beings. This makes the Ethereal Plane ideal for reconnaissance, spying on opponents, and moving around without being detected. The Ethereal Plane also disobeys the laws of gravity; a creature there can move up and down as easily as walking.

Deep Ethereal

To reach the Deep Ethereal, one needs a plane shift spell or arrive by means of a gate spell or magical portal.

Visitors to the Deep Ethereal are engulfed by roiling mist. Scattered throughout the plane are curtains of vaporous color, and passing through a curtain leads a traveler to a region of the Border Ethereal connected to a specific Inner Plane, the Material Plane, the Feywild, or the Shadowfell. The color of the curtain indicates the plane whose Border Ethereal the curtain conceals; see the Ethereal Curtains table.

Ethereal Curtains

Traveling through the Deep Ethereal to journey from one plane to another is unlike physical travel. Distance is meaningless, so although travelers feel as if they can move by a simple act of will, it’s impossible to measure speed and hard to track the passage of time. A trip between planes through the Deep Ethereal takes 1d10 × 10 hours, regardless of the origin and destination. In combat, however, creatures are considered to move at their normal speeds.

Ether Cyclones

An ether cyclone is a serpentine column that spins through the plane. The cyclone appears abruptly, distorting and uprooting ethereal forms in its path and carrying the debris for leagues. Travelers with a passive Wisdom (Perception) score of 15 or more receive 1d4 rounds of warning: a deep hum in the ethereal matter.

Travelers who can’t reach a curtain or portal leading elsewhere suffer the cyclone’s effect. Roll a d20 and consult the Ether Cyclone table to determine the effect on all creatures in the vicinity.

Ether Cyclones

The most common effect of an ether cyclone is to extend the duration of a journey. Each character in a group traveling together must make a DC 15 Charisma saving throw. If at least half the group succeeds, travel is delayed by 1d10 hours. Otherwise, the journey’s travel time is doubled. Less often, a group is blown into the Border Ethereal of a random plane. Rarely, the cyclone tears a hole in the fabric of the plane and hurls the party into the Astral Plane.

Ethereal Plane Encounters

Most encounters in the Border Ethereal are with creatures on the Material Plane whose senses or abilities extend into the Ethereal Plane (phase spiders, for example). Ghosts also move freely between the Ethereal and Material Planes.

In the Deep Ethereal, most encounters are with other travelers, particularly ones from the Inner Planes (such as elementals, genies, and salamanders), as well as the occasional celestial, fiend, or fey.

Feywild

Stepping into the portal was like settling into a warm bath, though the chill didn’t fade from the air. At first everything muted-the roar of the river around the rocks below, the chirping of frogs and crickets on shore, the evening bustle of the town behind him….A moment later, the world erupted into vibrant life. Frogs and night birds sang a chorus; the air was awash with autumn scents; the moonlight painted the flowers in iridescent blue, silver, and violet; and the rushing of the river became a complex symphony.

• James Wyatt

The Feywild, also called the Plane of Faerie, is a land of soft lights and wonder, a place of music and death. It is a realm of everlasting twilight, with glittering faerie lights bobbing in the gentle breeze and fat fireflies buzzing through groves and fields. The sky is alight with the faded colors of an ever-setting sun, which never truly sets (or rises for that matter); it remains stationary, dusky and low in the sky. Away from the settled areas ruled by the seelie fey that compose the Summer Court, the land is a tangle of sharp-toothed brambles and syrupy fens-perfect territory for the unseelie fey to hunt their prey.

The Feywild exists in parallel to the Material Plane, an alternate dimension that occupies the same cosmological space. The landscape of the Feywild mirrors the natural world but turns its features into spectacular forms. Where a volcano stands on the Material Plane, a mountain topped with skyscraper-sized crystals that glow with internal fire towers in the Feywild. A wide and muddy river on the Material Plane might be echoed as a clear and winding brook of great beauty. A marsh could be reflected as a vast black bog of sinister character. And moving to the Feywild from old ruins on the Material Plane might put a traveler at the door of an archfey’s castle.

The Feywild is inhabited by sylvan creatures, such as elves, dryads, satyrs, pixies, and sprites, as well as centaurs and magical creatures such as blink dogs, faerie dragons, treants, and unicorns. The darker regions of the plane are home to such malevolent creatures as hags, blights, goblins, ogres, and giants.

Seelie and Unseelie Fey

Two queens hold court in the Feywild, and most fey owe allegiance to one or the other. Queen Titania and her Summer Court lead the seelie fey, and the Queen of Air and Darkness, ruler of the Gloaming Court, leads the unseelie fey.

Seelie and unseelie do not directly correlate with good and evil, though many mortals make that equation. Many seelie fey are good, and many unseelie are evil, but their opposition to each other stems from their queens' jealous rivalry, not abstract moral concerns. Ugly denizens of the Feywild, such as fomorians and hags, are almost never members of either court, and fey of independent spirit reject the courts entirely.

The courts have warred at times, but they also compete in more-or-less friendly contests and even ally with one another in small and secret ways.

Fey Crossings

Fey crossings are places of mystery and beauty on the Material Plane that have a near-perfect mirror in the Feywild, creating a portal where the two planes touch. A traveler passes through a fey crossing by entering a clearing, wading into a pool, stepping into a circle of mushrooms, or crawling under the trunk of a tree. To the traveler, it seems like he or she has simply walked into the Feywild with a step. To an observer, the traveler is there one moment and gone the next.

Like other portals between planes, most fey crossings open infrequently. A crossing might open only during a full moon, on the dawn of a particular day, or for someone carrying a certain type of item. A fey crossing can be closed permanently if the land on either side is dramatically altered-for example, if a castle is built over the clearing on the Material Plane.

Optional Rules: Feywild Magic

Tales speak of children kidnapped by fey creatures and spirited away to the Feywild, only to return to their parents years later without having aged a day, and with no memories of their captors or the realm they came from. Likewise, adventurers who return from an excursion to the Feywild are often alarmed to discover upon their return that time flows differently on the Plane of Faerie, and that the memories of their visit are hazy. You can use these optional rules to reflect the strange magic that suffuses the plane.

Memory Loss

A creature that leaves the Feywild must make a DC 10 Wisdom saving throw. Fey creatures automatically succeed on the saving throw, as do any creatures, like elves, that have the Fey Ancestry trait. A creature that fails the saving throw remembers nothing from its time spent in the Feywild. On a successful save, the creature’s memories remain intact but are a little hazy. Any spell that can end a curse can restore the creature’s lost memories.

Time Warp

While time seems to pass normally in the Feywild, characters might spend a day there and realize, upon leaving the plane, that less or more time has elapsed everywhere else in the multiverse.

Whenever a creature or group of creatures leaves the Feywild after spending at least 1 day on that plane, you can choose a time change that works best for your campaign, if any, or roll on the Feywild Time Warp table. A wish spell can be used to remove the effect on up to ten creatures. Some powerful fey have the ability to grant such wishes and might do so if the beneficiaries agree to subject themselves to a geas spell and complete a quest after the wish spell is cast.

Feywild Time Warp

Shadowfell

Riven stood in the uppermost room of the central tower of his citadel-a fortress of shadows and dark stone carved in relief into the sheer face of a jagged peak…. The starless black vault of the plane’s sky hung over a landscape of gray and black, where lived the dark simulacra of actual things. Shadows and wraiths and specters and ghosts and other undead hung in the air around the citadel, or prowled the foothills and plains near it, so numerous their glowing eyes looked like swarms of fireflies. He felt the darkness in everything he could see, felt it as an extension of himself, and the feeling made him too big by half.

• Paul S. Kemp

The Shadowfell, also called the Plane of Shadow, is a dimension of black, gray, and white where most other color has been leached from everything. It is a place of darkness that hates the light, where the sky is a black vault with neither sun nor stars. The Shadowfell overlaps the Material Plane in much the same way as the Feywild. Aside from the colorless landscape, it appears similar to the Material Plane.

Landmarks from the Material Plane are recognizable on the Shadowfell, but they are twisted and warped—distorted reflections of what exists on the Material Plane. Where a mountain stands on the Material Plane, the corresponding feature on the Shadowfell is a jagged rock outcropping with a resemblance to a skull, a heap of rubble, or perhaps the crumbling ruin of a once-great castle. A forest on the Shadowfell is dark and twisted, its branches reaching out to snare travelers' cloaks, and its roots coiling and buckling to trip those who pass by.

Shadow dragons and undead creatures haunt this bleak plane, as do other creatures that thrive in the gloom, including cloakers and darkmantles.

Shadow Crossings

Similar to fey crossings, shadow crossings are locations where the veil between the Material Plane and the Shadowfell is so thin that creatures can walk from one plane to the other. A blot of shadow in the corner of a dusty crypt might be a shadow crossing, as might an open grave. Shadow crossings form in gloomy places where spirits or the stench of death lingers, such as battlefields, graveyards, and tombs. They manifest only in darkness, closing as soon as they feel light’s kiss.

Domains of Dread

In remote corners of the Shadowfell, it is easy to reach horrific demiplanes ruled over by accursed beings of terrible evil. The best known of these is the valley of Barovia, overlooked by the towering spires of Castle Ravenloft and ruled by Count Strahd von Zarovich, the first vampire. Beings of the Shadowfell called the Dark Powers created these domains as prisons these “darklords,” and through cruelty or carelessness trapped innocent mortals in these domains as well.

Optional Rule: Shadowfell Despair

A melancholic atmosphere pervades the Shadowfell. Extended forays to this plane can afflict characters with despair, as reflected in this optional rule.

When you deem it appropriate, though usually not more than once per day, you can require a character not native to the Shadowfell to make a DC 10 Wisdom saving throw. On a failure, the character is affected by despair. Roll a d6 to determine the effects, using the Shadowfell Despair table. You can substitute different despair effects of your own creation.

Shadowfell Despair

If a character is already suffering a despair effect and fails the saving throw, the new despair effect replaces the old one. After finishing a long rest, a character can attempt to overcome the despair with a DC 15 Wisdom saving throw. (The DC is higher because it’s harder to shake off despair once it has taken hold.) On a successful save, the despair effect ends for that character.

A calm emotions spell removes despair, as does any spell or other magical effect that removes a curse.

Evernight

The city of Neverwinter in the world of the Forgotten Realms has a dark reflection on the Shadowfell: the city of Evernight. Evernight is a city of cracked stone edifices and homes of rotten wood. Its roads are made mostly of trampled grave dust, and its few cobbled streets are missing enough stones that they appear pockmarked. The sky is corpse gray, and the breeze blows cold and humid, bringing a chill to the skin.

The city’s living residents include mad necromancers, corrupt purveyors of human flesh, worshipers of evil deities, and others who are able to make themselves useful and crazy enough to want to live here. But the living are a minority in Evernight, for the bulk of the population consists of the shambling dead. Zombies, wights, vampires, and other undead make the city their home, all under the watchful eyes of the ruling caste: intelligent, flesh-eating ghouls.

Rumors abound that this foul place mirrors one city on every world.

Inner Planes

He was lying on his back upon baked and smoldering stone, staring up at a smoky gray sky lit from distant and unseen fires. Around him, a sea of lava burped gouts of gas and jets of flame. The Elemental Plane of Fire.

Thank the fell ones, Vhok thought. I never thought I’d be so happy to be here.

• Thomas M. Reid

The Inner Planes surround and enfold 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, suspended within a churning realm known as the Elemental Chaos. These planes are all connected, and the border regions between them are sometimes described as distinct planes in their own right.

At their innermost edges, where they are closest to the Material Plane (in a conceptual if not a literal geographical sense), the four Elemental Planes resemble places in the Material Plane. The four elements mingle together as they do in the Material Plane, forming land, sea, and sky. But the dominant element exerts a strong influence on the environment, reflecting its fundamental qualities.

The inhabitants of this inner ring include aarakocra, azers, dragon turtles, gargoyles, genies, 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 they extend farther from the Material Plane, the Elemental Planes become increasingly alien and hostile. Here, in the outermost 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 outermost reaches of the Plane of Earth, and earth is all but impossible to find in the outermost 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 when discussing the Plane of Fire, for example, a speaker usually means the border region.

The outermost regions are largely the domains of elemental spirits barely recognizable as creatures. The creatures usually called elementals dwell here, including the Elemental Princes of Evil (primordial beings of pure elemental fury) and elemental spirits that spellcasters can bind into galeb duhrs, golems, invisible stalkers, magmin, and water weirds. These elemental creatures don’t need food or other sustenance on their home planes, because they are sustained by the elemental energies that saturate those planes.

Elemental Chaos

At the farthest 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. Reports indicate the existence of weird hybrid elementals native to the Elemental Chaos, but such creatures are seldom seen on other planes.

Plane of Air

The essential nature of air is movement, animation, and inspiration. Air is the breath of life, the winds of change, the fresh breeze that clears away the fog of ignorance and the stuffiness of old ideas.

The Plane of Air is an open expanse with constant winds of varying strength. Here and there, chunks of earth drift in the openness-the remnants of failed invasions by denizens of the Plane of Earth. These earth motes serve as homes for the creatures of elemental air, and many motes are covered with lush vegetation. Other creatures live on cloud banks infused with enough magic to become solid surfaces, strong enough to support towns and castles.

Drifting cloud banks can obscure visibility in any direction in the plane. Storms are frequent, mostly on par with a strong thunderstorm but occasionally more like fierce tornadoes or mighty hurricanes. The air is mild, except near the Plane of Water (where it is biting cold) and the Plane of Fire (where it is searing hot). Rain and snow fall only in the part of the plane nearest to the Plane of Water.

Most of the Plane of Air is a complex web of air streams, currents, and winds called the Labyrinth Winds. These range from stiff breezes to howling gales that can rip a creature apart. Even the most skilled flying creatures must navigate these currents carefully, flying with the winds, not against them.

Here and there among the Labyrinth Winds are hidden realms reachable only by following a particular sequence of flowing winds, and thus largely protected against attackers. One such realm is fabled Aaqa, a shining domain of silver spires and verdant gardens atop a fertile earth mote. The Wind Dukes of Aaqa are dedicated to law and good, and they maintain a vigilant watch against the depredations of elemental evil and the encroachment of the Elemental Chaos. They are served by aarakocra and a little-known race called the vaati.

The region of the Plane of Air nearest the Great Conflagration is called the Sirocco Straits. Hot, dry winds scour the earth motes in this area to dry and barren chunks of rock. Gargoyles and their allies from the Plane of Earth gather here to launch raids into the realm of Aaqa.

Between the Sea of Fire (on the Plane of Fire) and the Sirocco Straits is a towering firestorm called the Great Conflagration, sometimes called the Plane of Ash. Howling winds from the Plane of Air mix with the cinder storms and lava of the Plane of Fire to create an endless storm front-a wall of flames, smoke, and ash.

The thick ash obscures sight beyond a few dozen feet, and the battering winds make travel difficult. Here and there, ash clusters into floating realms where outlaws and fugitives take shelter.

At the other end of the plane, near the Frostfell (the plane of ice that borders the Plane of Water), is a region of frigid winds called the Mistral Reach. These gales drive snowstorms into the Frostfell and away from it, toward the heart of the plane. Earth motes in the reach are covered with snow and ice.

Plane of Earth

Earth symbolizes stability, rigidity, stern resolve, and tradition. The plane’s position opposite the Plane of Air in the ring of the Elemental Planes reflects its opposition to almost everything air represents.

The Plane of Earth is a chain of mountains rising higher than any mountain range in the Material Plane. It has no sun of its own, and no air surrounds the peaks of its highest mountains. Most visitors to the plane arrive by way of caves and caverns that honeycomb the mountains.

The largest cavern beneath the mountains, called the Great Dismal Delve or the Sevenfold Mazework, is home to the capital city of the dao, the City of Jewels. The dao take great pride in their wealth and send teams of slaves across the plane in search of new veins of ore and gemstones to exploit. Thanks to their efforts, every building and significant object in the city is made from precious stones and metals, including the slender gemstone-inlaid spires that top most buildings. The city is protected by a powerful spell that alerts the entire dao population if a visitor steals even a single stone. Theft is punishable by death, with punishment extending to the thief’s relatives.

The mountains nearest the Fountains of Creation (on the Plane of Fire) are called the Furnaces. Lava seeps through their caverns, and the air reeks of sulfur. The dao have great forges and smelting furnaces here to process their ores and shape their precious metals.

The border region between the planes of Water and Earth is a horrid swamp where twisted, gnarled trees and thick, stinging vines grow from the dense muck and slime. Here and there within the Swamp of Oblivion (also called the Plane of Ooze), stagnant lakes and pools play host to thickets of weeds and monstrous swarms of mosquitoes. The few settlements here consist of wooden structures suspended above the muck. Most are built on platforms between trees, but a few stand on stilts driven deep into the muck. No solid earth underlies the mud of the swamp, so houses built on poles eventually sink down into it.

It is said that any object cast into the Swamp of Oblivion can’t be found again for at least a century. Now and then, a desperate soul casts an artifact of power into this place, removing it from the multiverse for a time. The promise of powerful magic lures adventurers to brave the monstrous insects and hags of the swamp in search of these treasures.

The region of the plane nearest the Swamp of Oblivion is called the Mud Hills. Landslides constantly wear away the slopes of the hills, sending cascades of earth and stone into the bottomless swamp. The Plane of Earth seems to constantly regenerate the land, pushing new hills up as the old ones erode to nothing.

Plane of Fire

Fire represents vibrancy, passion, and change. At its worst, it is cruel and wantonly destructive, as the efreet often are, but at its best, fire reflects the light of inspiration, the warmth of compassion, and the flame of desire.

A blazing sun hangs at the zenith of a golden sky above the Plane of Fire, waxing and waning on a 24-hour cycle. It ranges from white hot at noon to deep red at midnight, so the darkest hours of the plane display a deep red twilight. At noon, the light is nearly blinding. Most business in the City of Brass (see below) takes place during the darker hours.

The weather on the plane is marked by fierce winds and thick ash. Although the air is breathable, creatures not native to the plane must cover their mouths and eyes to avoid stinging cinders. The efreet use magic to keep the cinder storms away from the City of Brass, but elsewhere in the plane, the wind is always at least blustery and rises to hurricane force during the worst storms.

The heat in the Plane of Fire is comparable to a hot desert on the Material Plane, and poses a similar threat to travelers (see “Extreme Heat” in chapter 5, “Adventure Environments”). The deeper one goes into the plane, the rarer water becomes. Beyond a point, the plane holds no sources of water, so travelers must carry their own supplies or produce water by magic.

The Plane of Fire is dominated by the vast Cinder Wastes, a great expanse of black cinders and embers crossed by rivers of lava. Roving bands of salamanders battle each other, raid azer outposts, and avoid the efreet. Ancient ruins dot the desert-remnants of forgotten civilizations.

A great range of volcanic mountains called the Fountains of Creation is home to azers. These rocky peaks curl from the edge of the Plane of Earth around the Cinder Wastes toward the fiery heart of the plane. At the edge of the plane, the mountains are also called the Plane of Magma. Fire giants and red dragons make their homes here, as well as creatures from the neighboring planes.

Lava flows through the volcanoes toward the Plane of Air and pools into a great lava sea, called the Sea of Fire, sailed by efreet and azers in great brass ships. Islands of obsidian and basalt jut up from the sea, dotted with ancient ruins and the lairs of powerful red dragons. On the shore of the Sea of Fire stands the City of Brass.

The City of Brass

Perhaps the best-known location in the Inner Planes is the City of Brass, on the shores of the Sea of Fire. This is the fabled city of the efreet, and its ornate spires and metal walls reflect their grandiose and cruel nature.

True to the nature of the Plane of Fire, everything in the city seems alive with dancing flames, reflecting the vibrant energy of the place.

Adventurers frequently come here on quests for legendary magic. If it’s possible to buy magic items at all, the City of Brass is the most likely place to find any item for sale, though the price might well be more than gold. The efreet are fond of trading in favors, especially when they have the upper hand in negotiations. Perhaps a magical disease or poison can be cured only with something that must be purchased in the bazaars of the city.

The heart of the city is the towering Charcoal Palace, where the tyrannical sultan of the efreet reigns supreme, surrounded by efreet nobles and a host of slaves, guardians, and sycophants.

Plane of Water

The nature of water is to flow, not like the gusting wind or the leaping flame, but smoothly and steadily. It is the rhythm of the tide, the nectar of life, the bitter tears of mourning, and the balm of sympathy and healing. Given time, it can erode all in its path.

A warm sun arcs across the sky of the Plane of Water, seeming to rise and set from within the water at the visible edge of the horizon. Several times a day, however, the sky clouds over and releases a deluge of rain, often accompanied by spectacular shows of lightning, before clearing up again. At night, a glittering array of stars and auroras bedecks the sky.

The Plane of Water is an endless sea, called the Sea of Worlds, dotted here and there with atolls and islands that rise up from enormous coral reefs that seem to stretch forever into the depths. The storms that move across the sea sometimes create temporary portals to the Material Plane and draw ships into the Plane of Water. Surviving vessels from countless worlds and navies ply these waters with little hope of ever returning home.

The weather on the plane is a lesson in extremes. If the sea isn’t calm, it is battered by storms. On rare occasions, a tremor in the planar firmament sends a rogue wave sweeping across the plane, swamping entire islands and driving ships down to the reefs.

Life flourishes in the upper reaches of the Sea of Worlds, called the Sea of Light because of the sunlight filtering down into the water. Aquatic humanoids craft castles and fortresses in the coral reefs. The marids are the distant stewards of this region, content to allow the lesser folk to compete for territory. The nominal emperor of the marids dwells in the Citadel of Ten Thousand Pearls, an opulent palace made of coral and studded with pearls.

The deeper extents of the plane, where no sunlight reaches, are called the Darkened Depths. Horrid creatures dwell here, and the absolute cold and crushing pressure mean a swift end to creatures accustomed to the surface or the Sea of Light. Krakens and other mighty leviathans claim this realm.

Any land that rises above the surface of the sea is hotly contested by the few air-breathers that live on the plane. Fleets of rafts and ships lashed together serve as solid ground where nothing else is available. Most natives of the plane never break the surface of the sea and thus ignore these habitations.

One of the few actual islands on the plane is the Isle of Dread. The island is connected to the Material Plane by means of a regular storm that sweeps over the island. Travelers who know the strange tides and currents of the plane can travel between worlds freely, but the storms also wreck ships from the Material Plane on the island’s shore.

The region of the Plane of Water nearest the Swamp of Oblivion (on the Plane of Earth) is called the Silt Flats. The water is thick with soil and sludge, and turns into muddy ground before giving way to the great swamp between the planes.

At the other extreme of the plane is the Sea of Ice, bordering the Frostfell. The frigid water is choked with icebergs and sheet ice, inhabited by the cold-loving creatures that inhabit the Frostfell. Drifting icebergs can carry these creatures farther into the Plane of Water to threaten ships and islands in warmer seas.

The Frostfell, also called the Plane of Ice, forms the border between the planes of Air and Water and is a seemingly endless glacier swept by constant, raging blizzards. Frozen caverns twist through the Plane of Ice, home to yetis, remorhazes, white dragons, and other creatures of cold. The inhabitants of the plane engage in a never-ending battle to prove their strength and ensure their survival.

Its dangerous monsters and bitter cold make the Frostfell a dangerous place to travel. Most planar voyagers keep to the air, braving the powerful winds and driving snow to avoid setting foot on the great glacier.

Outer Planes

Streamers of noxious gas streaked that crimson dome like dirty clouds. They whirled to form what looked like giant eyes staring down, eyes that were swept away before they could focus, only to form anew, again and again. Beneath the ruby glow lay a dark nightmare land of bare rock and flumes of sparks and gouting flame, where things slithered and scrambled halfseen in the shadows. Mountains clawed the ruby sky. The Land of Teeth, Azuth had once aptly called it, surveying the endless jagged rocks. This was the Greeting Ground, the realm of horror that had claimed the lives of countless mortals. He was whirling along above Avernus, uppermost of the Nine Hells.

• Ed Greenwood

If the Inner Planes are the raw matter and energy that makes up the multiverse, the Outer Planes provide the direction, thought, and purpose for its construction. Accordingly, many sages refer to the Outer Planes as divine planes, spiritual planes, or godly planes, for the Outer Planes are best known as the homes of deities.

When discussing anything to do with deities, 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. 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, many of the Outer Planes appear hospitable and familiar to natives of the Material Plane. But the landscape can change at a whim of the powerful forces that dwell on these planes, which can remake them completely, effectively erasing and rebuilding existence to better fulfill their divine needs.

Distance is a virtually meaningless concept on the Outer Planes. The perceptible regions of the planes can seem quite small, but they can also 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 Hells desire it. Or it could take weeks for travelers to make a grueling trek across a single layer.

The default Outer Planes are a group of sixteen planes that correspond to the eight alignments (excluding neutrality, which is represented by the Outlands, described in the section on “Other Planes”) and the shades of distinction between them.

The Outer Planes

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 is its essence, and a character 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 out of tune and more than a little uncomfortable.

The Upper Planes are the home of celestial creatures, including angels, couatls, and pegasi. The Lower Planes are the home of fiends: demons, devils, yugoloths, and their ilk. The planes in between host their own unique denizens: the construct race of modrons inhabit Mechanus, and the aberrations called slaadi thrive in Limbo.

Layers of the Outer Planes

Most of the Outer Planes include a number of distinct environments or realms. These realms are often imagined and depicted as a stack of related parts of the same plane, so travelers refer to them as layers. For example, Mount Celestia resembles a seven-tiered layer cake, the Nine Hells has nine layers, and the Abyss has a seemingly endless number of layers.

Most portals from elsewhere reach the first layer of a multilayered plane. This layer is variously depicted as the top or bottom layer, depending on the plane. As the arrival point for most visitors, the first layer functions like a city gate for that plane.

Traveling the Outer Planes

Traveling between the Outer Planes isn’t dissimilar from reaching the Outer Planes in the first place. Characters traveling by means of the astral projection spell can go from one plane into the Astral Plane, and there search out a color pool leading to the desired destination. Characters can also use plane shift to reach a different plane more directly. Most often, though, characters use portals-either a portal that links the two planes directly or a portal leading to Sigil, City of Doors, which holds portals to all the planes.

Two planar features connect multiple Outer Planes together: the River Styx and the Infinite Staircase. Other planar crossings might exist in your campaign, such as a World Tree whose roots touch the Lower Planes and whose branches reach to the Upper Planes, or it might be possible to walk from one plane to another in your cosmology.

The River Styx

This river bubbles with grease, foul flotsam, and the putrid remains of battles along its banks. Any creature other than a fiend that tastes or touches the water is affected by a feeblemind spell. The DC of the Intelligence saving throw to resist the effect is 15.

The Styx churns through the top layers of Acheron, the Nine Hells, Gehenna, Hades, Carceri, the Abyss, and Pandemonium. Tributaries of the Styx snake onto lower layers of these planes. For example, a tendril of the Styx winds through every layer of the Nine Hells, allowing passage from one layer of that plane to the next.

Sinister ferries float on the waters of the Styx, crewed by pilots skilled in negotiating the unpredictable currents and eddies of the river. For a price, these pilots are willing to carry passengers from plane to plane. Some of them are fiends, while others are the souls of dead creatures from the Material Plane.

The Infinite Staircase

The Infinite Staircase is an extra dimensional spiral staircase that connects the planes. An entrance to the Infinite Staircase usually appears as a nondescript door. Beyond the portal lies a small landing with an equally nondescript stairway leading up and down. The Infinite Staircase changes appearance as it climbs and descends, going from simple stairs of wood or stone to a chaotic jumble of stairs hanging in radiant space, where no two steps share the same gravitational orientation. It is said that one can find one’s heart’s desire on the Infinite Staircase through diligent searching of each landing.

Doors to the Infinite Staircase are often tucked away in dusty, half-forgotten places that no one frequents or pays any attention to. On any given plane, there can be multiple doors to the Infinite Staircase, though entrances aren’t common knowledge and are occasionally guarded by devas, sphinxes, yugoloths, and other powerful monsters.

Optional Rules

Each of the Outer Planes has peculiar characteristics that make traveling through it a unique experience. A plane’s influence can affect visitors in various ways, such as causing them to take on personality traits or flaws that reflect the disposition of the plane, or even shift alignment to more closely match the native inhabitants of the plane. Each plane’s description includes one or more optional rules that you can use to help make the adventurers' experiences on that plane memorable.

Optional Rule: Psychic Dissonance

Each of the Outer Planes emanates a psychic dissonance that affects visitors of an incompatible alignment-good creatures on the Lower Planes, evil ones on the Upper Planes-if they spend too much time on the plane. You can reflect this dissonance with this optional rule. At the end of a long rest spent on an incompatible plane, a visitor must make a DC 10 Constitution saving throw. On a failed save, the creature gains one level of exhaustion. Incompatibility between lawful and chaotic alignments doesn’t have the same effect, so Mechanus and Limbo lack this quality.

Mount Celestia

The single sacred mountain of Mount Celestia rises from a shining Silver Sea to heights barely visible and utterly incomprehensible, with seven plateaus marking its seven heavenly layers. The plane is the model of justice and order, of celestial grace and endless mercy, where angels and champions of good guard against incursions of evil. It is one of the few places on the planes where travelers can let down their guard. Its inhabitants strive constantly to be as righteous as possible. Countless creatures aim to reach the highest and most sublime peak of the mountain, but only the purest souls can. Gazing toward that peak fills even the most jaded of travelers with awe.

Optional Rule: Blessed Beneficence

In contrast to the dissonance experienced by evil creatures here, good creatures are literally blessed by the pervasive beneficence of the plane. Creatures of good alignment gain the benefit of the bless spell as long as they remain on the plane. In addition, finishing a long rest on the plane grants a good creature the benefit of a lesser restoration spell.

Bytopia

The two layers of the Twin Paradises of Bytopia are similar yet opposite: one is a tamed, pastoral landscape and the other an untamed wilderness, yet both reflect the plane’s goodness and its acceptance of law and order when necessary. Bytopia is the heaven of productive work, the satisfaction of a job well done. The goodness flowing through the plane creates feelings of goodwill and happiness in creatures dwelling there.

Optional Rule: Pervasive Goodwill

At the end of each long rest taken on this plane, a visitor that is neither lawful good nor neutral good must make a DC 10 Wisdom saving throw. On a failed save, the creature’s alignment changes to lawful good or neutral good (whichever is closer to the creature’s current alignment). The change becomes permanent if the creature doesn’t leave the plane within 1d4 days. Otherwise, the creature’s alignment reverts to normal after one day spent on a plane other than Bytopia. Casting the dispel evil and good spell on the creature also restores its original alignment.

Elysium

Elysium is home to creatures of unfettered kindness and compassion, and a welcome refuge for planar travelers seeking a safe haven. The plane’s bucolic landscapes glimmer with life and beauty in their prime. Tranquility seeps into the bones and souls of those who enter the plane. It is the heaven of well-earned rest, a place where tears of joy glisten on many a cheek.

Optional Rule: Overwhelming Joy

Visitors spending any time on this plane risk becoming trapped by overwhelming sensations of contentment and happiness. At the end of each long rest taken on this plane, a visitor must make a DC 10 Wisdom saving throw. On a failed save, the creature is unwilling to leave the plane before taking another long rest. After three failed saving throws, the creature never willingly leaves the plane and, if forcibly removed, does everything in its power to return to the plane. A dispel evil and good spell removes this effect from the creature.

The Beastlands

The Beastlands is a plane of nature unbound, of forests ranging from moss-hung mangroves to snow-laden pines, of thick jungles where the branches are woven so tight that no light penetrates, of vast plains where grains and wildflowers wave in the wind with vibrant life. The plane embodies nature’s wildness and beauty, but it also speaks to the animal within all living things.

Optional Rule: Hunter’s Paradise

Visitors to the Beastlands find their hunting and stalking capabilities improved, and characters have advantage on Wisdom (Animal Handling), Wisdom (Perception), and Wisdom (Survival) checks while there.

Optional Rule: Beast Transformation

Whenever a visitor slays a beast native to the plane, the slayer must succeed on a DC 10 Charisma saving throw or become transformed (as the polymorph spell) into the type of beast that was slain. In this form, the creature retains its intelligence and ability to speak. At the end of each long rest, the polymorphed creature can repeat the saving throw. On a successful saving throw, the creature returns to its true form. After three failed saving throws, the transformation can be undone only by a remove curse spell or similar magic.

Arborea

Larger than life, Arborea is a place of violent moods and deep affections, of whim backed by steel, and of passions that blaze brightly until they burn out. Its good-natured inhabitants are dedicated to fighting evil, but their reckless emotions sometimes break free with devastating consequences. Rage is as common and as honored as joy in Arborea. There the mountains and forests are extravagantly massive and beautiful, and every glade and stream is inhabited by nature spirits that brook no infringement. Travelers must tread lightly.

Arborea is home to many elves and elven deities. Elves born on this plane have the celestial type and are wild at heart, ready to battle evil in a heartbeat. Otherwise, they look and behave like normal elves.

Optional Rule: Intense Yearning

Keep track of how many days a visitor spends on Arborea. When the visitor leaves, it must make a Charisma saving throw against a DC of 5, plus 1 for each day spent on the plane. On a failed save, the creature becomes afflicted with a yearning to return to Arborea. As long as the effect persists, the creature has disadvantage on ability checks. At the end of each long rest, the creature can repeat the saving throw, ending the effect on a success. A dispel evil and good spell removes this effect from the creature.

Ysgard

Ysgard is a rugged realm of soaring mountains, deep fjords, and windswept battlefields, with summers that are long and hot, and winters that are wickedly cold and unforgiving. Its continents float above oceans of volcanic rock, below which are icy caverns so enormous as to hold entire kingdoms of giants, humans, dwarves, gnomes, and other beings. Heroes come to Ysgard to test their mettle not only against the plane itself, but also against giants, dragons, and other terrible creatures that thunder across Ysgard’s vast terrain.

Optional Rule: Immortal Wrath

Ysgard is the home of slain heroes who wage eternal battle on fields of glory. Any creature, other than a construct or undead, that is killed by an attack or a spell while on Ysgard is restored to life at dawn the next day. The creature has all its hit points restored, and all conditions and afflictions it suffered before its death are removed.

Limbo

Limbo is a plane of pure chaos, a roiling soup of impermanent matter and energy. Stone melts into water that freezes into metal, then turns into diamond that burns up into smoke that becomes snow, and on and on in an endless, unpredictable process of change. Fragments of more ordinary landscapes-bits of forest, meadow, ruined castles, and even burbling streams-drift through the disorder. The whole plane is a nightmarish riot.

Limbo has no gravity, so creatures visiting the plane float in place. A creature can move up to its walking speed in any direction by merely thinking of the desired direction of travel.

Limbo conforms to the will of the creatures inhabiting it. Very disciplined and powerful minds can create whole islands of their own invention within the plane, sometimes maintaining those places for years. A simpleminded creature such as a fish, though, might have less than a minute before the pocket of water surrounding it freezes, vanishes, or turns to glass. The slaadi live here and swim amid this chaos, creating nothing, whereas githzerai monks build entire monasteries with their minds.

Optional Rule: Power of the Mind

As an action, a creature on Limbo can make an Intelligence check to mentally move an object on the plane that it can see within 30 feet of it. The DC depends on the object’s size: DC 5 for Tiny, DC 10 for Small, DC 15 for Medium, DC 20 for Large, and DC 25 for Huge or larger. On a successful check, the creature moves the object 5 feet plus 1 foot for every point by which it beat the DC.

A creature can also use an action to make an Intelligence check to alter a nonmagical object that isn’t being worn or carried. The same rules for distance apply, and the DC is based on the object’s size: DC 10 for Tiny, DC 15 for Small, DC 20 for Medium, and DC 25 for Large or larger. On a success, the creature changes the object into another nonliving form of the same size, such as turning a boulder into a ball of fire.

Finally, a creature can use an action to make an Intelligence check to stabilize a spherical area centered on the creature. The DC depends on the radius of the sphere. The base DC is 5 for a 10-foot-radius sphere; each additional 10 feet added to the radius increases the DC by 5. On a successful check, the creature prevents the area from being altered by the plane for 24 hours, or until the creature uses this ability again.

Pandemonium

Pandemonium is a plane of madness, a great mass of rock riddled with tunnels carved by howling winds. It is cold, noisy, and dark, with no natural light. Wind quickly extinguishes nonmagical open flames such as torches and campfires. It also makes conversation possible only by yelling, and even then only to a maximum distance of 10 feet. Creatures have disadvantage on any ability check that relies on hearing. Most of the plane’s inhabitants are creatures that were banished to the plane with no hope of escape, and many of them have been driven mad by the incessant winds or forced to take shelter in places where the winds die down until they sound like distant cries of torment.

Optional Rule: Mad Winds

A visitor must make a DC 10 Wisdom saving throw after each hour spent among the howling winds. On a failed save, the creature gains one level of exhaustion. A creature that reaches six levels of exhaustion while on this plane doesn’t die. Instead, the creature gains a random form of indefinite madness, as described in chapter 8, “Running the Game.” Finishing a long rest doesn’t reduce a creature’s exhaustion level unless the creature can somehow escape the maddening winds.

The Abyss

The Abyss embodies all that is perverse, gruesome, and chaotic. Its virtually endless layers spiral downward into ever more appalling forms.

Each layer of the Abyss boasts its own horrific environment. Although no two layers are alike, they are all harsh and inhospitable. Each layer also reflects the entropic nature of the Abyss. In fact, much of what one sees or touches on the plane seems to be in a decaying, crumbling, or corroded state.

Optional Rule: Abyssal Corruption

A non-evil visitor that finishes a long rest in the Abyss must make a DC 10 Charisma saving throw. On a failure, the creature becomes corrupted. Refer to the Abyssal Corruption table to determine the effects of this corruption. You can substitute different corruption effects of your own creation.

After finishing a long rest, a corrupted creature can make a DC 15 Charisma saving throw. On a successful save, the corruption effect ends. A dispel evil and good spell or any magic that removes a curse also ends the effect.

If a corrupted creature doesn’t leave the plane within 1d4+2 days, its alignment changes to chaotic evil. Casting the dispel evil and good spell on the creature restores its original alignment.

Abyssal Corruption

Important Layers

The layers of the Abyss are defined by the demon lords who rule them, as the following examples illustrate. More information about the demon lords can be found in the Monster Manual.

The Gaping Maw

Demogorgon’s layer in the Abyss is a vast wilderness of savagery and madness known as the Gaping Maw, where even powerful demons go insane with fear. Reflecting Demogorgon’s dual nature, the Gaping Maw consists of a massive primeval continent covered in dense jungle, surrounded by a seemingly endless expanse of ocean and brine flats. The Prince of Demons rules his layer from two serpentine towers, which emerge from a turbid sea. Each tower is topped with an enormous fanged skull. The spires constitute the fortress of Abysm, where few creatures can venture without descending into madness.

Thanatos

If Orcus had his way, all planes would resemble his dead realm of Thanatos, and all creatures would become undead under his control. Under its black sky, Thanatos is a land of bleak mountains, barren moors, ruined cities, and forests of twisted black trees. Tombs, mausoleums, gravestones, and sarcophagi litter the landscape. Undead swarm across the plane, bursting from their tombs and graves to tear apart any creatures foolish enough to journey here. Orcus rules Thanatos from a vast palace known as Everlost, crafted of obsidian and bone. Set within a howling wasteland called Oblivion’s End, the palace is surrounded by tombs and burial sites dug into the sheer slopes of narrow valleys, creating a tiered necropolis.

The Demonweb

Lolth’s layer is an immense network of thick, magical webbing that forms passageways and cocoon-like chambers. Throughout the web, buildings, structures, ships, and other objects hang as if caught in a spider’s snare. The nature of Lolth’s web creates random portals throughout the plane, drawing such objects in from demiplanes and Material Plane worlds that figure into the schemes of the Spider Queen. Lolth’s servants also build dungeons amid the webbing, trapping and hunting Lolth’s hated enemies within crisscrossing corridors of web-mortared stone.

Far beneath these dungeons lie the bottomless Demonweb Pits where the Spider Queen dwells. There, Lolth is surrounded by her handmaidens-yochlol demons created to serve her and which outrank mightier demons while in the Spider Queen’s realm.

The Endless Maze

Baphomet’s layer of the Abyss is a never-ending dungeon, the center of which holds the Horned King’s enormous ziggurat palace. A confusing jumble of crooked hallways and myriad chambers, the palace is surrounded by a mile-wide moat concealing a maddening series of submerged stairs and tunnels leading deeper into the fortress.

The Triple Realm

The Dark Prince Graz’zt rules over the realm of Azzagrat, which encompasses three layers of the Abyss. His seat of power is the fantastic Argent Palace in the city of Zelatar, whose bustling markets and pleasure palaces draw visitors from across the multiverse in search of obscure magical lore and perverse delights. By Graz’zt’s command, the demons of Azzagrat present a veneer of civility and courtly comity. However, the so-called Triple Realm holds as much danger as any other part of the Abyss, and planar visitors can vanish without a trace in its maze like cities and in forests whose trees have serpents for branches.

Death Dells

Yeenoghu rules a layer of ravines known as Death Dells. Here, creatures must hunt to survive. Even the plants, which must bathe their roots in blood, snare the unwary. Yeenoghu’s servants, helping to sate their master’s hunger as he prowls his kingdom seeking prey, capture creatures from the Material Plane for release in the Gnoll Lord’s realm.

Carceri

The model for all other prisons in existence, Carceri is a plane of desolation and despair. Its six layers hold vast bogs, fetid jungles, windswept deserts, jagged mountains, frigid oceans, and black ice. All form a miserable home for the traitors and backstabbers that are trapped on this prison plane.

Optional Rule: Prison Plane

No one can leave Carceri easily. Magical efforts to leave the plane by any spell other than a wish simply fail. Portals and gates that open onto the plane become one-way only. Secret ways out of the plane exist, but they are hidden and well guarded by traps and deadly monsters.

Hades

The layers of Hades are called the Three Glooms-places without joy, hope, or passion. A gray land with an ashen sky, Hades is the destination of many souls that are unclaimed by the gods of the Upper Planes or the fiendish rulers of the Lower Planes. These souls become larvae and spend eternity in this place that lacks a sun, a moon, stars, or seasons. Leaching away color and emotion, this gloom is more than most visitors can stand. The “Shadowfell Despair” rule earlier in the chapter can be used to represent a visitor’s despair.

Optional Rule: Vile Transformation

At the end of each long rest taken on the plane, a visitor must make a DC 10 Wisdom saving throw. On a failed save, the creature gains one level of exhaustion, which can’t be removed while the creature remains in Hades. If the creature reaches six levels of exhaustion, it doesn’t die. Instead, the creature permanently transforms into a larva, whereupon all levels of exhaustion afflicting the creature are removed.

A larva is a miserable fiend that retains the facial features of its previous form but has the body of a fat worm. A larva has only a few faint memories of its previous life and the statistics in the larva stat block.

Hades is crawling with larvae. Night hags, liches, and rakshasas harvest them for use in vile rituals. Other fiends like to feed on them.

Gehenna

Gehenna is the plane of suspicion and greed. It is the birthplace of the yugoloths, which dwell here in great numbers. A volcanic mountain dominates each of the four layers of Gehenna, and lesser volcanic earthbergs drift in the air and smash into the greater mountains.

The rocky slopes of the plane make movement here difficult and dangerous. The ground inclines at least 45 degrees almost everywhere. In places, steep cliffs and deep canyons present more challenging obstacles. Hazards include volcanic fissures that vent noxious fumes or searing flames.

Gehenna has no room for mercy or compassion. The fiends living here are among the greediest and most selfish in all the multiverse.

Optional Rule: Cruel Hindrance

The plane’s cruel nature makes it difficult for visitors to help one another. Whenever a visitor casts a spell with a beneficial effect, including a spell that restores hit points or removes a condition, the caster must first make a DC 10 Charisma saving throw. On a failed save, the spell fails, the spell slot is expended, and the action is wasted.

The Nine Hells

The Nine Hells of Baator inflame the imaginations of travelers, the greed of treasure seekers, and the battle fury of all moral creatures. It is the ultimate plane of law and evil and the epitome of premeditated cruelty. The devils of the Nine Hells are bound to obey the laws of their superiors, but they rebel within their individual castes. Most undertake any plot, no matter how foul, to advance themselves. At the very top of the hierarchy is Asmodeus, who has yet to be bested. If he were to be vanquished, the victor would rule the plane in turn. Such is the law of the Nine Hells.

Optional Rule: Pervasive Evil

Evil pervades the Nine Hells, and visitors to this plane feel its influence. At the end of each long rest taken on this plane, a visitor that isn’t evil must make a DC 10 Wisdom saving throw. On a failed save, the creature’s alignment changes to lawful evil. The change becomes permanent if the creature doesn’t leave the plane within 1d4 days. Otherwise, the creature’s alignment reverts to normal after one day spent on a plane other than the Nine Hells. Casting the dispel evil and good spell on the creature also restores its original alignment.

The Nine Layers

The Nine Hells has nine layers. The first eight are each ruled by archdevils that answer to Asmodeus, the Archduke of Nessus, the ninth layer. To reach the deepest layer of the Nine Hells, one must descend through all eight of the layers above it, in order. The most expeditious means of doing so is the River Styx, which plunges ever deeper as it flows from one layer to the next. Only the most courageous adventurers can withstand the torment and horror of that journey.

Avernus

No planar portals connect directly to the lower layers of the Nine Hells, by Asmodeus’s orders.

As such, the first layer of Avernus is the arrival point for visitors to the plane. Avernus is a rocky wasteland with rivers of blood and clouds of biting flies. Fiery comets occasionally fall from the darkened sky and leave fuming impact craters behind. Empty battlefields are littered with weapons and bones, showing where the legions of the Nine Hells met enemies on their native soil and prevailed.

The archduchess Zariel rules Avernus, supplanting her rival, Bel, who has fallen out of Asmodeus’s favor and is forced to serve as Zariel’s advisor. Tiamat, the Queen of Evil Dragons, is a prisoner on this layer, ruling her own domain but confined to the Nine Hells by Asmodeus in accordance with some ancient contract (the terms of which are known only to Tiamat and the Lords of the Nine).

Zariel’s seat of power is a soaring basalt citadel festooned with the partially incinerated corpses of guests who failed to earn the archduchess’s favor. Zariel appears as an angel whose once-beautiful skin and wings have been ruined by fire. Her eyes burn with a furious white light that can cause creatures looking upon her to burst into flame.

Dis

Dis, the second layer of the Nine Hells, is a labyrinth of canyons wedged between sheer mountains rich with iron ore. Iron roads span and wend through the canyons, watched over by the garrisons of iron fortresses perched atop jagged pinnacles.

The second layer takes its name from its current lord, Dispater. A manipulator and deceiver, the archduke is devilishly handsome, bearing only small horns, a tail, and a cloven left hoof to distinguish him from a human. His crimson throne stands in the heart of the Iron City of Dis, a hideous metropolis that is the largest in the Nine Hells. Planar travelers come here to conspire with devils and to close deals with night hags, rakshasas, incubi, succubi, and other fiends. Dispater collects a piece of every deal through special provisions that are added to contracts signed on his layer of the Nine Hells.

Dispater is one of Asmodeus’s most loyal and resourceful vassals, and few beings in the multiverse can outwit him. He is more obsessed than most devils with striking deals with mortals in exchange for their souls, and his emissaries work tirelessly to foster evil schemes in the Material Plane.

Minauros

The third layer of the Nine Hells is a stench-ridden bog. Acidic rain spills from the layer’s brown skies, thick layers of scum cover its putrid surface, and yawning pits lie in wait beneath the murk to engulf careless wanderers. Cyclopean cities of ornately carved stone rise up from the bog, including the great city of Minauros for which the layer is named.

The slimy walls of the city rise hundreds of feet into the air, protecting the flooded halls of Mammon. The Archduke of Minauros resembles a massive serpent with the upper torso and head of a hairless, horned humanoid. Mammon’s greed is legendary, and he is one of the few archdevils who will trade favors for gold instead of souls. His lair is piled high with treasures left behind by those who tried-and failed-to best him in a deal.

Phlegethos

Phlegethos, the fourth layer, is a fiery landscape whose seas of molten magma brew hurricanes of hot wind, choking smoke, and pyroclastic ash. Within the fire-filled caldera of Phlegethos’s largest volcano rises Abriymoch, a fortress city cast of obsidian and dark glass. With rivers of molten lava pouring down its outer walls, the city resembles the sculpted center piece of a gigantic, hellish fountain.

Abriymoch is the seat of power for the two archdevils who rule Phlegethos in tandem: Archduke Belial and Archduchess Fierna, Belial’s daughter. Belial is a handsome, powerfully built devil who exudes civility, even as his words carry an undercurrent of threat. His daughter is a statuesque devil whose beauty encases the blackest heart in the Nine Hells. The alliance of Belial and Fierna is unbreakable, for both are aware that their mutual survival hinges on it.

Stygia

The fifth layer of the Nine Hells is a freezing realm of ice within which cold flames burn. A frozen sea surrounds the layer, and its gloomy sky crackles with lightning.

Archduke Levistus once betrayed Asmodeus and is now encased deep in the ice of Stygia as punishment. He rules this layer all the same, communicating telepathically with his followers and servants, both in the Nine Hells and on the Material Plane.

Stygia is also home to its previous ruler, the serpentine archdevil Geryon, who was dismissed by Asmodeus to allow the imprisoned Levistus to regain his rule. Geryon’s fall from grace has spurred much debate within the infernal courts. No one is certain whether Asmodeus had some secret cause to dismiss the archdevil or whether he is testing Geryon’s allegiance for some greater purpose.

Malbolge

Malbolge, the sixth layer, has outlasted many rulers, among them Malagard the Hag Countess and the archdevil Moloch. Malagard fell out of favor and was struck down by Asmodeus in a fit of pique, while her predecessor, Moloch, still lingers somewhere on the sixth layer as an imp, plotting to regain Asmodeus’s favor. Malbolge is a seemingly endless slope, like the sides of an impossibly huge mountain. Parts of the layer break off from time to time, creating deadly and deafening avalanches of stone. The inhabitants of Malbolge live in crumbling fortresses and great caves carved into the mountainside.

Malbolge’s current archduchess is Asmodeus’s daughter, Glasya. She resembles a succubus with her small horns, leathery wings, and forked tail. She inherited her cruelty and love of dark schemes from her father. The citadel that serves as her domicile on the slopes of Malbolge is supported by cracked pillars and buttresses that are sturdy yet seem on the verge of collapse. Beneath the palace is a labyrinth lined with cells and torture chambers, where Glasya confines and torments those who displease her.

Maladomini

The seventh layer, Maladomini, is ruin-covered wasteland. Dead cities form a desolate urban landscape, and between them lie empty quarries, crumbling roads, slag heaps, the hollow shells of empty fortresses, and swarms of hungry flies.

The Archduke of Maladomini is Baalzebul, the Lord of Flies. A bloated fiend with the lower body of an enormous slug, Baalzebul’s form was inflicted on him by Asmodeus as punishment for wavering loyalty. Baalzebul is a miserable and degenerate monstrosity who has long conspired to usurp Asmodeus, yet has failed at every turn. He carries a curse that causes any deal made with him to lead to calamity. Asmodeus occasionally shows Baalzebul favor for reasons no other archduke can fathom, though some suspect that the Archduke of Nessus still respects the worthiness of this fallen adversary.

Cania

Cania, the eighth layer of the Nine Hells, is an icy hellscape, whose ice storms can tear flesh from bone. Cities embedded in the ice provide shelter for guests and prisoners of Cania’s ruler, the brilliant and conniving archdevil Mephistopheles.

Mephistopheles dwells in the ice citadel of Mephistar, where he plots to seize the Throne of Baator and conquer the planes. He is Asmodeus’s greatest enemy and ally, and the Archduke of Nessus appears to trust Mephistopheles’s counsel when it is offered.

Mephistopheles knows he can’t depose Asmodeus until his adversary makes a grave miscalculation, and so both wait to see what circumstances might turn them against each other. Mephistopheles is also a godfather of sorts to Glasya, further complicating the relationship.

Mephistopheles is a tall, striking devil with impressive horns and a cool demeanor. He trades in souls, as do other archdevils, but he rarely gives his time to any creatures not worthy of his personal attention. His instincts are as razor sharp as Cania’s frigid winds, and it is said that only Asmodeus has ever deceived or thwarted him.

Nessus

The lowest layer of the Nine Hells, Nessus is a realm of dark pits whose walls are set with fortresses. There, pit fiend generals loyal to Asmodeus garrison their diabolical legions and plot the conquest of the multiverse. At the center of the layer stands a vast rift of unknown depth, out of which rises the great citadel-spire of Malsheem, home to Asmodeus and his infernal court.

Malsheem resembles a gigantic hollowed-out stalagmite. The citadel is also a prison for souls that Asmodeus has locked away for safekeeping. Convincing him to release even one of those souls comes at a steep price, and it is rumored that the Archduke of Nessus has claimed whole kingdoms in the past for such favors.

Asmodeus most often appears as a handsome, bearded humanoid with small horns protruding from his forehead, piercing red eyes, and flowing robes. He can also assume other forms and is seldom seen without his ruby-tipped scepter in hand. Asmodeus is the most cunning and well-mannered of archdevils. The ultimate evil he represents can be seen only when he wills it so, or if he forgets himself and flies into a rage.

Acheron

Acheron has four layers, each made of enormous iron cubes floating in an airy void. Sometimes the cubes collide. Echoes of past collisions linger throughout the plane, mingling with the sounds of armies colliding. That’s the nature of Acheron: strife and war, as the spirits of fallen soldiers join in endless battle against orcs devoted to Gruumsh, goblinoids loyal to Maglubiyet, and legions assembled by other warmongering gods.

Optional Rule: Bloodlust

Acheron rewards a creature for harming other creatures by imbuing that creature with the strength to keep fighting. While on Acheron, a creature gains temporary hit points equal to half its hit point maximum whenever it reduces a hostile creature to 0 hit points.

Mechanus

On Mechanus, law is reflected in a realm of clockwork gears, all interlocked and turning according to their measure. The cogs seem to be engaged in a calculation so vast that no deity can fathom its purpose. Mechanus embodies absolute order, and its influence can be felt on those who spend time here.

Modrons are the primary inhabitants of Mechanus. The plane is also home to the creator of the modrons: a godlike being called Primus.

Optional Rule: Law of Averages

While on Mechanus, creatures always use the average damage result for attacks and spells. For example, an attack that normally deals 1d10+5 damage always deals 10 damage on Mechanus.

Optional Rule: Imposing Order

At the end of each long rest taken on this plane, a visitor that isn’t lawful neutral must make a DC 10 Wisdom saving throw. On a failed save, the creature’s alignment changes to lawful neutral. The creature’s alignment reverts to normal after one day spent on a plane other than Mechanus. Casting the dispel evil and good spell on the creature also restores its original alignment.

Arcadia

Arcadia thrives with orchards of perfectly lined trees, ruler-straight streams, orderly fields, perfect roads, and cities laid out in geometrically pleasing shapes. The mountains are unblemished by erosion. Everything on Arcadia works toward the common good and a flawless form of existence. Here, purity is eternal, and nothing intrudes on harmony.

Night and day are determined by an orb that floats above Arcadia’s highest peak. Half of the orb radiates sunlight and brings about the day; the other half sheds moonlight and brings on the starry night. The orb rotates evenly without fail, spreading day and night across the entire plane.

The weather in Arcadia is governed by four allied demigods called the Storm Kings: the Cloud King, the Wind Queen, the Lightning King, and the Rain Queen. Each one lives in a castle surrounded by the type of weather that king or queen controls.

Hidden below Arcadia’s beautiful mountains are numerous dwarven kingdoms that have withstood the passage of millennia. Dwarves born on this plane have the celestial type and are always brave and kindhearted, but otherwise they look and behave like normal dwarves.

Optional Rule: Planar Vitality

While on this plane, creatures can’t be frightened or poisoned, and they are immune to disease and poison.

Other Planes

A variety of realms exist between or beyond the other planes.

The Outlands and Sigil

The Outlands is the plane between the Outer Planes. It is the plane of neutrality, incorporating a little of everything and keeping all aspects in a paradoxical balance-simultaneously concordant and in opposition. The plane has varied terrain, with prairies, mountains, and shallow rivers.

The Outlands is circular, like a great disk. In fact, those who envision the Outer Planes as a wheel point to the Outlands as proof, calling it a microcosm of the planes. That argument might be circular, since the arrangement of the Outlands inspired the idea of the Great Wheel in the first place.

Around the outside edge of the circle, evenly spaced, are the gate-towns: sixteen settlements, each built around a portal leading to one of the Outer Planes. Each town shares many of the characteristics of the plane where its gate leads. Planar emissaries often meet in these towns, so it isn’t unusual to see strange pairings, such as a celestial and a fiend arguing in a tavern while sharing a fine bottle of wine.

Given the fact that you can ride a horse in the Outlands from a heaven to a hell, a planar-themed campaign can be set there without the need for planar travel. The Outlands is the closest the Outer Planes come to being like a world on the Material Plane.

Gate-Towns of the Outlands

Sigil, City of Doors

At the center of the Outlands, like the axle of a great wheel, is the Spire-a needle-shaped mountain that rises high into the sky. Above this mountain’s narrow peak floats the ring-shaped city of Sigil, its myriad structures built on the ring’s inner rim. Creatures standing on one of Sigil’s streets can see the city curve up over their heads and-most disconcerting of all-the far side of the city directly overhead. Called the City of Doors, this bustling planar metropolis holds countless portals to other planes and worlds.

Sigil is a trader’s paradise. Goods, merchandise, and information come here from across the planes. The city sustains a brisk trade in information about the planes, particularly the command words or items required for the operation of particular portals. Portal keys of all kinds are bought and sold here.

The city is the domain of the inscrutable Lady of Pain, a being as old as gods and with purposes unknown to even the sages of her city. Is Sigil her prison? Is she the fallen creator of the multiverse? No one knows. Or if they do, they aren’t telling.

Demiplanes

Demiplanes are extra dimensional spaces that come into being by a variety of means and boast their own physical laws. Some are created by spells. Others exist naturally, as folds of reality pinched off from the rest of the multiverse. Theoretically, a plane shift spell can carry travelers to a demiplane, but the proper frequency required for the tuning fork would be extremely hard to acquire. The gate spell is more reliable, assuming the caster knows of the demiplane.

A demiplane can be as small as a single chamber or large enough to contain an entire realm. For example, a Mordenkainen’s magnificent mansion spell creates a demiplane consisting of a foyer with multiple adjoining rooms, while the land of Barovia (in the Ravenloft setting) exists entirely within a demiplane under the sway of its vampire lord, Strahd von Zarovich. When a demiplane is connected to the Material Plane or some other plane, entering it can be as simple as stepping through a portal or passing through a wall of mist.

The Far Realm

The Far Realm is outside the known multiverse. In fact, it might be an entirely separate universe with its own physical and magical laws. Where stray energies from the Far Realm leak onto another plane, matter is warped into alien shapes that defy understandable geometry and biology. Aberrations such as mind flayers and beholders are either from this plane or shaped by its strange influence.

The entities that abide in the Far Realm itself are too alien for a normal mind to accept without strain. Titanic creatures swim through nothingness there, and unspeakable things whisper awful truths to those who dare listen. For mortals, knowledge of the Far Realm is a struggle of the mind to overcome the boundaries of matter, space, and sanity. Some warlocks embrace this struggle by forming pacts with entities there. Anyone who has seen the Far Realm mutters about eyes, tentacles, and horror.

The Far Realm has no well-known portals, or at least none that are still viable. Ancient elves once opened a vast portal to the Far Realm within a mountain called Firestorm Peak, but their civilization imploded in bloody terror and the portal’s location-even its home world-is long forgotten. Lost portals might still exist, marked by an alien magic that mutates the area around them.

Known Worlds of the Material Plane

Worlds of the Material Plane are infinitely diverse. The most widely known worlds are the ones that have been published as official campaign settings for the D&D game over the years. If your campaign takes place on one of these worlds, that world belongs to you in your campaign. Your version of the world can diverge wildly from what’s in print.

On Toril (the heroic-fantasy world of the Forgotten Realms setting), fantastic cities and kingdoms stand amid the remains of ancient empires and realms long forgotten. The world is vast, its dungeons rich with history. Beyond the central continent of Faerun, Toril includes the regions of Al-Qadim, Kara-Tur, and Maztica.

On Oerth (the sword-and-sorcery world of the Greyhawk setting), heroes such as Bigby and Mordenkainen are driven by greed or ambition. The hub of the region called the Flanaess is the Free City of Greyhawk, a city of scoundrels and archmagi, rife with adventure. An evil demigod, Iuz, rules a nightmarish realm in the north, threatening all civilization.

On Krynn (the epic-fantasy world of the Dragonlance setting), the return of the gods is overshadowed by the rise of the evil dragon queen Takhisis and her dragons and dragon armies, which plunge the continent of Ansalon into war.

On Athas (the sword-and-sorcery world of the Dark Sun setting), a drop of water can be worth more than a human life. The gods have abandoned this desert world, where powerful sorcerer-kings rule as tyrants, and metal is a scarce and precious commodity.

On Eberron (the heroic-fantasy world of the Eberron setting), a terrible war has ended, giving rise to a cold war fueled by political intrigue. On the continent of Khorvaire, magic is commonplace, dragonmarked houses rival kingdoms in power, and elemental vehicles make travel to the far corners of the world possible.

On Aebrynis (the heroic-fantasy world of the Birthright setting), scions born from divine bloodlines carve up the continent of Cerilia. Monarchs, prelates, guildmasters, and great wizards balance the demands of rulership against the threat of horrible abominations born from the blood of an evil god.

On Mystara (a heroic-fantasy world born out of the earliest editions of the D&D game), diverse cultures, savage monsters, and warring empires collide. The world is further shaped by the meddling of the Immortals-former adventurers raised to nearly divine status.