Ethereal Plane

The Ethereal Plane is a foggy expanse with low visibility divided into two distinct domains, the Border Ethereal and Deep Ethereal. The Border Ethereal exists as an empty parallel plane to the Material and Elemental Planes known as the Inner Planes. Here, structures and geographical features are mirrored but shrouded in a gray fog. This part of the Ethereal Plane is an empty echo of the Material Plane, overlapping but not interfering. https://www.worldanvil.com/world/location/5c4a4373-2708-4e74-bd41-7660c4e49ae3/edit# The Deep Ethereal lacks these orientating reference points, with only roiling mists churning in all directions. However, travelers of the Deep Ethereal will occasionally see flashes of light that can lead them to random locations within the Border Ethereal.
The first step in using the Ethereal Plane is figuring out how to get there. Luckily, there are several ways to do this. The etherealness spell allows characters to enter the Border Ethereal for the purposes of magical travel or invisibility. The Deep Ethereal can only be entered directly through the plane shift or gate spell or the use of some other kind of magical portal. While there are no rules around traveling from the Border to Deep Ethereal, it stands to reason that creatures who can enter the Border Ethereal will be able to find their way to the Deep Ethereal with the help of a guide.
Those looking to use the Ethereal Plane as a means of infiltration should remember that it is still possible to be seen by a creature on the Material Plane that has true seeing or see invisibility active. Also, hallow, forbiddance, and wall of force can be used to prevent intruders from the Ethereal Plane. This means that if your party plans to go up against some magically gifted adversaries, they may well have the means to counter extraplanar incursions. Beyond infiltration, the misty expanse of the Ethereal Plane is also a great place for hiding valuables, as shown with the secret chest spell.

Geography

It’s said that for those lost in the Deep Ethereal, the warm glow of the Radiant Citadel’s Auroral Diamond will provide a path through the misty surroundings to a place of safety.

Reflections of the Material Plane

A character can see into the Material Plane from any point on the Border Ethereal. This is something like peering through a cracked and dirty pane of glass. From some angles, the material world can be seen clearly; from others, it is distorted and warped out of all proportion; from yet others, it appears monochromatic and wreathed in mist. This close relationship between the Material and Ethereal Planes causes other phenomena. Tenebrous wisps of ectoplasm catch on the tiny impressions in the Ethereal Plane caused by physical objects passing through it. If a wall is built in the Material Plane, it can be seen through the rolling ethereal fog. Wait long enough though and these mists will form into an ethereal duplicate of the wall. This wall is only slightly more solid than any other piece of ectoplasm, but it can be seen without having to peer into the Material Plane. Over time, the ethereal landscape forms into a ghostly reflection of the real world. If the real-world object were to be destroyed or moved (say, if the wall were demolished), then the ethereal duplicate would slowly dissolve back into freefloating mist. This process takes some time, so it is possible to glimpse what the landscape used to look like by examining the local Ethereal Plane. The time taken for an ethereal duplicate to form depends on the nature of the object. For example, a character comes across the ruin of a castle and wishes to learn who once dwelled there. The castle was destroyed six months ago, but stood for sixty years prior to its destruction. The ethereal duplicates of the wooden outbuildings have long since faded, but the stone structure of the castle itself will endure for five years before dissolving. The character might find duplicate suits of armour or other metal fittings, but only if their real-world counterparts had been in the same place for at least twelve years. While exploring, the character finds an ancient shield on the wall, bearing the crest of the castle’s owner. The real-world version of this shield may have long since been shattered, but its ethereal duplicate still exists for a time. Like items shaped of ectoplasm, ethereal duplicates have a little solidity. Pushing through them requires a Strength check at a DC equal to the AC of the real-world item; a character may add his Wisdom or Charisma bonus (whichever is higher) to this roll. Dissolving ethereal duplicates are even less resilient – reduce the DC by 1d10 points. Failing the Strength check means that the character loses five feet of movement, but can try to move through the obstacle again if he has movement left. A character can pick up the ethereal duplicate of a sword and wield it against a ghost, but the duplicate will dissolve in 1d10 hours. The ethereal duplicates of magical items usually have no special properties – reduce the bonus of the item by three, or the caster level by twelve, so a sword +5 would create an ethereal duplicate sword +2, while a wand of fireballs with a caster level of seven would create an entirely non-magical duplicate. Only permanent items create ethereal duplicates, and remember a moving item does not create an ethereal duplicate at all. That sword +5 would have to be left on a shelf for a month to produce an ethereal duplicate, and the duplicate would only exist for a few days before dissolving if the sword was moved. Violent weather or major discharges of energy on the Material Plane can also cause the local ethereal duplicates to dissolve. Roll percentile dice; if the result is lower than the damage inflicted by an energy attack, the ethereal duplicates within a radius equal to the damage x 5 dissolve within 1d10 rounds. Ethereal duplicates only exist on the Ethereal Plane. Any attempt to remove them from their home plane causes them to instantly dissolve.

Ethereal Duplicates

Material Time to Form Time to Dissolve Living creatures Never – Most plants One year One day Trees and bushes One year Two weeks Fabrics, most common items Six months Two weeks Gold, silver, gems One month One month Iron and steel One month Two weeks per year of existence Wooden buildings Six months One month Stone buildings Three months One month per year of existence Lead Instantaneous One year per year of existence Other substances 22 – (object AC) (Object AC – 10) in months

Localized Phenomena

• No Gravity: Individuals on a plane with this trait merely float in space.

• Sparse Life: Life is widespread, but sparse. Plant life exists in scrublands and small copses and vast herds of animals are unknown.

• Static Weather: Weather does not change here. While there might still be clouds, storms, winds and other such phenomena, they are as unmoving as mountains and rivers. Meteorology becomes geography.

• Minor necrotic bias: Undead are common.

Climate

Though largely empty, the Ethereal Plane is not without perils. The endless roiling mists make navigating the plane a near-impossible task. Even when traversing the Border Ethereal, adventurers must take care not to become lost and find themselves in the Deep Ethereal with no way out. Beyond finding oneself lost amongst the fog, there are certain other dangers that travelers of the Ethereal Plane need to be aware of:

Ether cyclones

Ether cyclones are powerful storms of ethereal essence that rove across the Deep Ethereal. If they cannot be avoided, these twisting cyclones can impose significant setbacks on travelers in the Ethereal Plane. At best, getting caught in a cyclone will extend the duration of your journey. At worst, you could be hurled to a random location on one of the planes that border the Ethereal Plane, including the silvery expanse of the Astral Plane. Most ether cyclones don't physically harm adventurers, though there is a rumored standing storm known as the Keening Gloom from which no one who has entered has ever returned.

Ethereal Cyclone by Chad Watson via Midjourney

When traveling the Ethereal Plane, travelers with a passive Wisdom score of 15 or more receive 1d4 rounds of warning before suffering the cyclone’s full effect, which can be determined with a d20 roll after consulting the ether cyclone table in the Dungeon Master’s Guide.

Fauna & Flora

Monsters

The occasional phase spider or ghost may take notice of a traveling party of adventurers, and nefarious creatures like night hags use the Ethereal Plane to intrude on the dreams of mortals.
Due to the Ethereal Plane’s nature as a connection between other planes, most creatures found here will be travelers themselves, likely a wandering Fey, fiend, or even a djinn from the bordering Elemental Planes. A traveler in the Deep Ethereal might also encounter a citizen or scout from the Radiant Citadel, the only known hub of civilization, culture, or trade within the Ethereal Plane.

Tourism

Traveling in the Ethereal Plane

An adventurer might seek to travel to the Ethereal Plane for several reasons. A creature on the Ethereal Plane cannot be seen or heard by someone on the Material Plane, allowing it to be used strategically to avoid enemies. Similarly, a creature in the Border Ethereal can bypass solid objects on the Material Plane. This makes infiltrating a location without proper defenses against extraplanar incursions all too easy for creatures that can travel between the Ethereal and Material Plane.
Those brave enough to travel to the Deep Ethereal can use the Ethereal Plane as a gateway to travel the multiverse. Curtains of vaporous color are scattered throughout the Deep Ethereal that, when passed through, can lead travelers to regions of the Border Ethereal connected to one of the Elemental Planes, the Material Plane, The Feywild, or the Shadowfell. This makes the knowledge of how to safely travel the Ethereal Plane a powerful bargaining chip for purveyors of extraplanar travel.

Reflections of buildings from the Prime Material plane as they are seen from the Ethereal Plane

How beings in the Prime Material Plane are often seen from the Border Ethereal Plane by Unknown

Teleportation Portal into the Ethereal plane, scene from the Ethereal plane.

The Radiant Citadel

Alternative Name(s)

The Æther

Type

Plane of Existence