Acheron

Acheron is an iron-shod plane that is known as the Infernal Battlefield or the Infinite Battlefield. The plane is home to the constant battles and wars without meaning, rebels without causes, soldiers who love to fight whether they have reason to, and the hordes of goblins, hobgoblins and orcs warring between themselves. Archeron is located between Mechanus and the Nine Hells, making it the most lawful of the evil planes. While most might point towards the Devils and the Nine Hells as being the ultimate idea of what law and evilness should look like, Acheron is more lawful and not quite as evil. Acheron is the home of those who commit evil but only secondarily, their main aim being order and law enforced on those who don’t follow their set laws.
There are four layers in descending order Avalas, Thuldanin, Tintibulus, and Ocanthus; with the topmost layer being the most habitable and the bottom layer being the least habitable, which is a common trend among all Outer Planes as even Mount Celestia’s highest slopes aren’t fit for the normal adventurer. Each layer is composed of massive shapes floating around in the atmosphere, they crash into one another destroying anything on their surfaces and continue their endless drifting. Across every block are the massive armies waiting for their block to come in contact with another and they can continue their endless wars.

Geography

An Outsider’s Perspective Compared to most other planes, Acheron is a wasteland though it holds that position along with several other evil planes. Visiting this plane is not for the faint-hearted as most portals are not actually on land, but rather leaves you floating in space and ‘falling’ towards the closest cube. Of course, if you have no way to halt your fall your first ‘step’ will be more a splat as you slam into a cube. If you can survive the fall down, all you have to worry about next are the ferocious battles that are constantly taking place across the first layer, Avalas.
The sounds of battle, and the slamming of cubes, is constant in this plane as the noise echoes from cube to cube. Those who visit this plane have a very specific reason for being here, and quickly deal with their business and promptly leave before they are ‘hired’ as a mercenary, impaled on spikes because the Mercykillers think you broke a vague law or enslaved by a moving city and forced to become part of the living walls. Creatures of good or chaotic alignment would find this plane to be appalling, but for those who crave war for the sake of fighting, for carrying out orders without regard to its purpose, and for imposing your power over others, this is a violent heaven.
A Native’s Perspective Planes of Law, 1995 TSR Inc. Planes of Law, 1995 TSR Inc.
This plane is considered a safe place for many to visit with the Devils of the Nine Hells and is untouched by the Blood War. There is an enforced order through conformity, with little thought if that conformity is good. Armies wage war against each other, their only objective is the destruction of each other and the imposing of law and order on the other. There is little thought of accepting others for their differences, and in fact, that type of thinking is tortured out of creatures who try to express it.
The creatures who live here are those who loved to battle, regardless of why they warred. They roam these massive geometric shapes, waiting for when they may crash into another cube drifting through this plane and lead a charge against its inhabitants. The strongest armies on this plane are the armies of goblinoids and the armies of the orcs and its not surprising that they are constantly waging wars and striking at each other. The goblins despise the orcs and their lack of law, while the orcs are led by their god trying to find a home somewhere in the planes after fleeing from Gehenna and the Nine Hells after trying to take on more than they could.
Apart from the goblinoid and orc petitioners are the petitioners of duergar whose original deity who was exiled from the other dwarven deities in Mount Celestia, and they are a grave and somber lot who live on the second layer, Thuldanin. In their duergar city, they are constantly producing weapons to help protect themselves from the monsters who roam Acheron. The other major faction on this plane is the Mercykillers who see mercy as weakness and weakness as death. They are after order and punishment, for only punishment breaks the souls of those who would go against the group and against the order.

Ecosystem

Absolute Souls Many claim that every effect on Acheron has an opposite and equal effect. If you cast a fire spell, a cold spell somewhere else in the plane goes off as well. If a creature dies on the plane, another creature is born to this plane. Many go on to assume that the number of creatures on this plane is therefore finite and that you can never have more creatures on this plane than the set number, though no one knows what the number is. Many armies take this to heart and have decided that the only way to grow their numbers is to cause war and kill everyone that is not them, thus allowing more of their own petitioners to join their ranks.
Other creatures think this as well, except that they think this only applies to the petitioners, those who are already dead and it is their soul that has come here for their eternal resting place. Mortal creatures, like humans from The Material Plane or elves from the Feywild, do not count against the number of absolute souls allowed on the plane at one time, and thus many armies will hire mortals to be mercenaries… or if they mortals don’t wish to be mercenaries, they will simply press them into slavery and force them to fight for the army instead. Many see this as a loophole so that they may grow their army without having to lose any of their petitioners, only mortals who are only useful as being expendable.
Atmosphere The atmosphere of this plane is much like The Material Plane, though the light is never brighter than a dull, overcast day and gets as dim as a full moon. No one is sure where this light comes from, but its dim shining can be seen everywhere. When cubes pass in front of the light, it causes beams of light and shadow, making many think there is a cube out there who glows with intense light, but its an infinite distance away as no one has ever seen it.
The natural hazards of this plane come mostly from the floating geometric shapes that will routinely crash into one another, destroying anything that is unlucky enough to exist on the surface of the blocks. Most creatures and armies have made their homes inside of the iron blocks where they are protected from being smashed into oblivion, though cave-ins still pose a threat. The most dangerous layer due to its atmosphere is the last layer, Ocanthus, as it is filled with flat shards of black ice that are a few inches to a few miles across. They shoot forward with great speed at all sorts of angles, causing any creature who arrives on the bottom layer to become punctured with hundreds of wounds in a matter of minutes or have their head sliced off if they are truly unfortunate.
The weather on this plane is aptly known as brooding, with its gray light and cold winds that howl through the plane. Blizzards and ice storms fed by the River Styx on the first layer can cause horrible problems for the armies during their battles, and the iron cubes that make up every layer suck all the warmth out of those who live here.

Tourism

Travel to the Plane Arriving on this plane is can be done through portals from the Nine Hells or Mecanus, though many of these portals are free-floating and thus when a creature appears, they appear in the middle of nothing and begin falling to whatever surface is closest to them. There are a handful of portals that are locked to specific cubes, though they are heavily guarded by armies and any trespassers, which is everyone not part of that group, is either enslaved or killed if they dare resist. Of course, you could also journey to this plane by paying the ferrymen to take you along the River Styx as it moves across the top layer of the plane and is even said that it ends at the bottom of this plane, though no one has been able to prove it.
If you are able to locate a portal on this plane, they appear to be spherical and when you touch them they emit a chord of music. A harmonious sound means the portal will take you to Mechanus, while a discordant sound means the portal leads to Baator, the Nine Hells. If the sphere makes no noise when you touch it, it will take you to the Astral Plane. These portals exist free of any cube, though they are locked into a specific space in the plane and must typically be reached by a creature who has the ability to fly. Of course, sometimes these cubes will pass through the space of the portal, in which case you can access the portals quickly, though they do not work as they are passing through a cube.
Traversing the Plane Planes of Law, 1995 TSR Inc. Planes of Law, 1995 TSR Inc.
Traveling through this plane is simple, so long as you pay attention to where the other geometric shapes are located across the plane. Many armies, so focused on battle, will find themselves smashed to oblivion as another cube slams into the one they are fighting over. While these two cubes are knocked into each other, a quick traveler can cross on to the next cube by simply stepping over to the other cube, gravity always pulls a creature to the center of the cube, making it easy to walk along the sides of the cubes.
Each cube is large enough to hold a city or large enough to hold kingdoms, many say that the smaller the cube, the older it is as it slams into the others, slowly breaking itself up into smaller geometric shapes. There are several massive cubes that show little damage or cracks, and many assume those cubes are new and to be avoided as no one has mined through the iron cube and made tunnels to protect yourself from collisions. Most cities exist on the inside of cubes, though gods have the power of pushing other cubes away from theirs.
The top layer cubes are made of solid iron and you must mine your way into the cube in order to start up a settlement. The second layer, Thuldanin, is made up of hollow cubes and following pits into the cube you can find mountains of old machinery that have been turned into stone. The third layer, Tintibulus, is made up of hundreds of different geometric shapes all floating through the void, the more they crash into each other, the more they form smaller, more complex geometric shapes. Finally, the fourth layer is made up of flat shards of black ice that range in size from a few inches to a few miles wide and long. Due to their impossible thin thickness, they are dangerous and capable of slicing through metal as if it weren’t even there.
The Birds On the top layer, Avalas, are massive flocks of birds who fly from cube to cube. These flocks watch for battles and feast on the dead bodies leftover and many see these flocks of sparrows, hawks, buzzards, ravens, pigeons, and more as signs of good luck… though if birds are ever encountered as solitary, that is a sign of horrible and bad luck and there are complicated rituals used to be rid of bad luck.

Type

Plane of Existence

Location under

Lower Planes