Pentalithic Ramblings

Coterminous with nearly all other non-transitive planes, the Astral Plane is the keystone to interplanar travel. Most teleportation type spells that cross planar boundaries rely on the Astral Plane, and will not function on planes such as the Faerie Plane that are disconnected from the Astral Plane. Many psionic powers are also dependent on the Astral Plane.

Though it is possible to physically enter the Astral Plane like any other plane, most travellers who are not native to the plane instead travel via astral projection. During astral projection, the traveller is connected to their body by a silver cord, which is impervious to most damage¹.

Planescape

The Astral Plane is a vast, starry void filled with a thin atmosphere. Here, you can move in any direction you desire simply by thinking about it, and apart from the occasional monster, there are few or no hazards. Anyone physically travelling through the Astral Plane who has the requirement to breath treats it as a high-altitude environment².

However, occasionally while travelling the Astral Plane you might come upon an area of complete void. Anything that contacts such an area is instantly destroyed, similar to a Sphere of Annihilation. However, unlike a Sphere, it cannot be moved through force of will, though someone in possession of a Talisman of the Sphere can attempt to carve out a Sphere of Annihilation from the larger mass³.

Casting the gate spell upon an area of void cannot destroy it as it could a Sphere of Annihilation. Most of the time, it will instead tear a gap in the spatial fabric, catapulting everyone nearby into a random plane. A rod of cancellation also cannot negate an area of void, though it does cause an explosion and reduce the void’s size a little.

Sometimes, storms will spring up in the Astral Plane. These manifest as a vortex, pulling in nearby creatures⁴. An astral storm usually lasts for several hours⁵, and the powerful winds buffet anyone who gets caught inside, hurting them and, if they are astrally projecting, even damaging their silver cord⁶. While caught in a storm, it becomes a lot harder to control your personal gravity direction⁷.

Magical portals leverage the Astral Plane as their mode of transportation. Though passing through such a portal seems instant from the perspective of a traveller, from the Astral Plane these portals appear as dark conduits winding across the sky. A two-way portal appears as only a single conduit whose direction periodically reverses, though if someone has just passed through, it will always be flowing in that direction. With a little effort, it’s possible for an astral traveller to hitch a ride on such a conduit⁸, causing them to emerge from one of the ends of the portal.

There is much debris strewn throughout the Astral Plane, and on occasion, something valuable may be found simply laying around – a lost Secret Chest, a bag of holding that someone tried to place inside a portable hole, acid-resistant items that were stored in a bag of devouring, or even the corpses of past travellers.

There are a handful of long-dead deities floating deep within the Astral Plane; most notable are the corpses of Tethys and Velka. The corpse of a deity is something like an island floating in the void, usually with an altered gravity trait relative to the main Astral Plane.

Connections

Many planes are coterminous with the Astral Plane, including a vast array of demiplanes of all shapes and sizes. From the Astral Plane, a coterminous plane other than the Far Realm appears as a colorful sphere of various sizes. The standard planes, which includes the Material Plane and all the Inner and Outer Planes, are all represented by spheres of around 8,000 miles (12,000 km) in diameter, whereas demiplanes are typically represented by spheres less than 2,500 miles (4,000 km) in diameter.

These spheres are not fixed in place within the Astral Plane – they move along predefined paths. For example, the Inner and Outer planes rotate around the Material Plane. You can enter a given plane simply by sinking into its sphere from any direction, and the location you end up at within the plane depends on where you sank into the sphere; though this does not allow precise selection of your destination, you can at least ensure you end up somewhere in a specific general area.

Each portal-sphere in the Astral Plane is unique and as such the appearance can identify the plane. The following table lists the appearance of the sphere for all the major planes.

Plane	Appearance
Heaven	Lavender with silvery sparkles and patches of green
Hell	Crimson, with periodic blotches of flame-like orange
Mechanicus	Steel grey, with thin black great circles partitioning the surface
Errata	Constantly shifting colours, usually covering the entire rainbow
Arborea	Brown, with many small patches of green
Material Plain	Deep blue, with patches of green, brown, grey, etc, and white clouds wafting across (in other words, a lot like Earth from space but with more water and different continents)
Plane of Fire	Orange, yellow, and red, in shifting chaotic patterns
Plane of Earth	Mottled grey and moss green
Plane of Water	Deep blue, with occasional brown “clouds” wafting across the surface
Plane of Air	Sky blue, with white clouds wafting over it
Plane of Life	White, with occasional swirls of yellow and bright blue
Plane of Decay	Black, but with specks of grey

The Far Realm’s connection to the Astral Plane is different. Rather than a sphere, it’s a massive torus stretching across the plane, which slowly rotates. The major diameter of this torus is incredibly large; no-one has measured it precisely, but it’s thought to be close to 4 billion miles (6 billion km). The minor diameter is around 10,000 miles (16,000 km). Its colour is primarily a mottled grey, but with some splashes of colour mixed in. For example, blue is prominent near the areas where the River Styx or Sapphire River flows into the Far Realm from Hell and Heaven respectively.

Inhabitants

Despite its vastness, the Astral Plane has few permanent residents, and most of those that do exist are rare but powerful. A catalogue of all known astral races would have fewer than 30 entries. Some of the better-known ones are described briefly here.

Mercanes

The mercanes are a race of interplanar traders and the primary source in the Material Plane for most extraplanar resources. Their city, Màoshūn⁹, is a demiplane directly conterminous with the Astral Plane, but a thriving suburb has also grown up around the astral sphere leading to the city, which is a deep blue with a profusion of yellow flecks. This suburb consists of several floating islands, each with their own gravity bearing a single building. They are not connected by bridges, for the Astral Plane’s inherent gravity trait is sufficient to move from island to island.

Astral Dragons

There are several types of astral dragons, including the Chrome Dragon¹⁰, the Deep Dragon¹¹, the Occult Dragon¹², the Time Dragon¹³, and the Void Dragon¹³. They spend their time roaming the Astral Plane, occasionally stopping by some demiplane for food or other needs. Rarely do they actually enter the Material Plane.

Witchwyrds

Witchwyrds¹⁴ are a four-armed humanoid race which, like the mercanes, travel the Astral Plane as merchants. Unlike the mercanes, they do not have a central city; they are nomads, living in their caravans as they travel all over the Astral Plane. They also visit the Material Plane less frequently than the mercanes. The witchwyrds are best known for their unusual ability to catch a magic missile and later throw it back at the enemy.

Astral Leviathan

The Astral Leviathan¹³ is a massive whale-like creature that swims through the Astral Plane, looking for food. Though its many eyes and mouth full of teeth would seem to shout danger, astral leviathans are generally peaceful as long as they aren’t starving, plus they are actually intelligent and can be reasoned with. The mercanes use them like beasts of burden for transporting their wares to other planes.

Behemoth

The creature known as a behemoth looks a lot like a huge floating rock, with some kind of mouth on the bottom that usually remains closed. Travellers through the Astral Plane generally treat the behemoth as harmless, for it appears to ignore all travellers. Indeed, on occasion actual settlements have sprung up on the back of a behemoth. What is less widely known, however, is that a behemoth is the main body of an interdimensional creature whose mouth is more widely known and feared as a bag of devouring. Each behemoth has up to eight such mouths which it can insert into other planes to search for food. Every so often, its lower, visible mouth opens to let out the buildup of waste that it has devoured. Occasionally, valuable items can be found amongst this waste.

Elohim

The elohim¹³ are a bizarre bipedal race who roam the Astral Plane, creating demiplane after demiplane only to eventually abandon them. The usual pattern is, they create a demiplane complete with sentient creatures, rule over them for awhile, then get bored of them and move on to something new. It’s largely thanks to the elohim that the Astral Plane is dotted with thousands upon thousands of demiplanes, most of them relatively small. Elohim don’t care about other travellers as long as they’re left alone. If you’re somehow in their way, they will usually politely ask you to leave before resorting to cruder tactics.

Astral Shark

The Astral Shark¹⁵ is one of the most feared predators of the Astral Plane. Though they’ll eat almost anything, they seem to have a strong preference for travellers who are astrally projecting, and their ability to sever such a traveller’s silver cord is the main reason they are so feared. They are even more dangerous than an astral storm, as they can snap the cord in a single bite if lucky¹⁶. Indeed, they are not all that strong individually, though they tend to hunt in groups.

Umbral Blot

Occasionally, a patch of astral void somehow gains sentience. This is what is known as an Umbral Blot, also called a Blackball¹⁷. Though rare, they are exceptionally dangerous and should be avoided by all but the strongest parties.

Pseudonatural Races

Sometimes, survivors of the mutational Far Realms may escape back into the Astral Plane and come together with others like them to form small settlements. These usually spring up near the Far Realm boundary, and can serve both as a warning to travellers intending to visit the Far Realm and a last-minute supply stop for such travellers. The most common pseudonatural races you might encounter are trolls, with elves, goblins, and orcs coming in second.