Shadowfell

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.

Geography

• The most striking and immediate impression a visitor to the Plane of Shadow experiences is the lack of color and light; no sun, moon, or stars adorned the vault of the inky black sky, and all things look as if the color has leached out, leaving nothing but black and white, which in the dimness are more like "dark black" and "light black". A light source only illuminates half the distance it normally would, flames and fires put out less heat, and spells that deal with light or fire were less predictable and prone to failure, whereas shadow spells are enhanced. On the other hand, although it would not illuminate as far, any light source on the plane could be spotted at a distance of up to ten times its normal range of illumination, such as the contrast to the constant gloom, similar to a star in the night sky. Even a light source that only put out shadowy illumination, like a darkness spell or a lantern burning shadow light oil, could be seen up to five times its range of illumination.
• Gravity and time are the same on the Shadowfell as on the Prime, but because the Shadowfell is magically morphic the landscape is a dark, twisted echo of what exists on the Prime. Upon entering the Plane of Shadow, the local features are usually quite similar: casting shadow walk in a forest puts you in a shadow forest; casting it underwater drops you in a similar body of water, etc. But from that starting point, the landscape diverges rapidly away from the familiar, and on subsequent visits from the same starting point, it diverges in different ways, making mapping the Shadowfell a useless endeavor. Landmarks are usually recognizable but altered in some bizarre way: buildings might be constructed in a different style, built with different materials, at a different location, and/or in any condition from dilapidated ruins to their normal appearance, for example, or otherwise strange and distorted. Similar sites were sometimes called "shadow analogs".[16]
• Due to the ever-changing landscape, the Plane of Shadow is subject to relatively frequent but very small earthquakes (called shadow quakes) that resembled an earthquake spell in an area about two hundred feet (sixty meters) in diameter. For those on the ground, the damage is equivalent to a Prime earthquake, but shadow quakes can also disrupt the shadow walk spell and dump unfortunate travelers onto the Shadowfell in the middle of the disturbance at a place very likely unknown and far from their destination.
• Some areas on the Plane of Shadow seemed to have an affinity with the Negative Energy Plane and life-draining undead such as shadows, ghosts, and vampires. These "dark lands" have a minor negative-dominant trait and unprotected visitors immediately feel the life force being sucked from their bodies—unless they exited the dark land quickly, all that is left of them is a pile of ash. Someone with protection from negative energy can stop and admire the utter desolation in an otherwise forlorn landscape, and perhaps make the acquaintance of the truly inimical undead. Thankfully, no natural vortices open into dark lands regions, preventing the unwary from stepping through into almost certain death, and keeping the creatures that thrive there from having easy access to other planes. Material Plane locations such as desecrated burial mounds, haunted battlefields, and necromantic foci frequently had a dark land echo on the Shadowfell.
• Other less dangerous but quite unsettling echoes occurred in areas analogous to towns and cities in the Prime Material Plane. They were nothing more than mirages, but familiar faces and places seen through the macabre mirror of the Shadowfell can be very demoralizing. Structures might appear altered, dislocated, destroyed, or replaced entirely by something else. Mirages of the living have visages of distorted nightmares but were still recognizable enough to give travelers a jolt of fear and revulsion.
• Air, water, and food exist on this plane, supporting plants, animals, and some humanoids adapted to the shadow environment. Visitors could survive indefinitely if they were willing to endure thick, foul-smelling water, food that oozed dark blood, and a pervasive nip of cold in the air. A visitor can never feel warm, would often hear or sense the presence of things that weren't there, and could never shake the feeling of being watched. It is a constantly unsettling place. Over time, exposure to the Plane of Shadow alters living things, increasing various traits and abilities but also some vulnerabilities. Emotions and the ability to experience them seem to fade over time for those imbued with shadow stuff.
• The morphic nature of the Shadowfell can produce strange effects, mainly in areas like the Black Rift that are especially morphic, and with events that have a particular affinity with the plane, like death. For example, in the Black Rift alone, a pile of bodies caused more skeletons to appear, until there were thousands. More bizarre are the strange biers upon which dead bodies spontaneously appear, apparently drawn from wherever they rested, anywhere in existence, only to disappear after a few seconds, presumably to wherever they'd come from. Stalactites in a cave drip ephemeral shadow stuff, which iwas reabsorbed into the plane rather than form a puddle. Even common mushrooms bore realistic humanoid faces, capable of twitching or blinking. More significantly, forests of grasping tendrils sprouted from some surfaces and reached for passersby, similar to the black tentacles spell

Localized Phenomena

• Known as "shadowstuff", the material of the Shadowfell can be manipulated by illusionists to form semi-real monsters and quasi-real evocations that were still effective (to a lesser degree) even if the target successfully disbelieves the illusion.
• Another tool of illusionists is the shadow well spell, which could turn a creature's shadow into a temporary gateway into the Shadowfell. If successful, the victim is sucked into the Shadowfell through his or her shadow and spends a few moments in a pocket realm (a very tiny demiplane attached to the Shadowfell) being terrorized by dark phantasms. No physical harm results from this spell, but mental and emotional trauma resulting in a fear response was possible.
• An unsuccessful attempt to build a gate to the Shadowfell can result in what was termed a failed Shadow Gate. A being that steps through one is taken only momentarily to the Plane of Shadow, but in that moment a "seed of shadow" is implanted in their flesh. This could cause their flesh to be subsumed by shadow, and they would see it mist away into darkness. Many die, reduced to bare skeletons, but those who survived acquired the powers of a dark creature.

Fauna & Flora

• The Shadowfell is home to a mysterious form of undead called shadows, other "shadow" creatures such as the shadow mastiff and shadow dragon, and a race of humanoids known as shades. In addition to those, there were numerous other inhabitants, such as communities of shadar-kai, Shadovar, and dark ones.
• Probably the most dominant race of beings on the Plane of Shadow were the shades—ancestors of ancient Netherese humans who resided on the plane in their floating city for centuries and acquired many abilities from immersion in shadow essence.
• Other creatures that are either native to the plane or attracted to it included bodaks, cloakers, darkweavers, ephemera of all kinds, veserabs, liches, nightshades, shadar-kai, shadurakul, spectres, and wraiths. Occasionally, animals and monsters will wander or fall into a vortex to the Shadowfell and become trapped there. Those that survive eventually take on shadow-given abilities, carve out a niche in the ecosystem, and prey on whatever attracted their attention. Examples include apes, basilisks, bears, owlbears, rats, umber hulks, and wolves. Such creatures can give rise to dark creatures, shadowy counterparts of natural creatures.
• Shadow demons also inhabit this plane. These fiends are responsible for the creation of the race known as krinth, having interbred with Netherese slaves.
• Shadow sea serpents are not native to the Plane of Shadow but were bred there by the Shadovar, crossing warm-blooded carnivorous orcas with vile shadow creatures. These serpents hunt in packs both in the sea and on land.
• The Shadowfell is also prominently populated with dead creatures such as ghosts, specters, and other undead who for whatever reason refuse to leave the Shadowfell.

History

• The special and unique nature of this plane caused not only cosmologists to speculate about its origins, but visitors and planar travelers as well. Some believed the Plane of Shadow had spontaneously formed as a demiplane out of the Ethereal Plane.
• However, most cosmologists and planewalkers with a sense of adventure liked to talk about the legend of the Shining Citadel. Briefly, the legend postulated that the Plane of Shadow was once bright and colorful like the Material Plane, but at some point in the distant past a mysterious group who worshiped the plane's creator took all of the light, color, and most of the life-force from the rest of the plane and concentrated it into a mighty citadel. One would think that a structure containing most of the energy from an entire plane of existence would be hard to miss, but no one has ever found the Shining Citadel, except perhaps, as the legend states, those who venture into the deepest parts of the Plane of Shadows and never return.
• A theory bandied about among sages stated that the Underdark was bottomless because it eventually became the Plane of Shadow. The only evidence supporting this hypothesis was that permanent portals to the Shadowfell were increasingly common the deeper one delved.

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 for these “darklords,” and through cruelty or carelessness trapped innocent mortals in these domains as well.

Type

Dimensional plane

Shadowfell Despair: A melancholic atmosphere pervades the Shadowfell. Extended forays to this plane can afflict travelers with despair.
No more than once per day, a traveler not native to the Shadowfell makes a DC 10 Wisdom saving throw. On a failure, the traveler is affected by despair. Roll a d6 to determine the effects, using the Shadowfell Despair table.

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