The Infinite Battlefield of Acheron

The Infinite Battlefield of Acheron was an Outer Plane representing alignments between lawful evil and lawful neutral with an emphasis on law.

DESCRIPTION

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Acheron was the bridge between the ultimate order of Nirvana and the regimented evil of the Nine Hells and as such, each layer emphasized order over evil. The landmasses on each layer were blocks of geometric simplicity the size of nations floating in a sea of air. The blocks would slowly collide and part without causing any upheaval or tremor, allowing beings to move to a new block if desired. The dance of the blocks was carefully orchestrated and creatures of high intelligence could usually discern a pattern for an area by studying the motions. It was said gravity pulled toward the centre of the blocks but in practical terms, gravity was normal to each surface.

LAYERS

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AVALAS
Acheron was sometimes known as the "iron-shod battle planes of Acheron" (the Battleplains) due to the characteristics of the first layer, Avalas. The blocks of the top plane were black with a metallic hardness that allowed the sounds of battle and troop movements to reverberate loudly. Avalas had the most block-like worlds and the highest population as the armies of the Outer Planes spent their afterlife clashing in the neutral territory over differences both subtle and gross. The landscape consisted of cone-shaped mountains and pits plus the iron fortresses of the various armies. The only other remarkable feature of this layer was the river Styx that would bubble up from one pit, meander across two or three sides of a block, and then disappear down another pit. The Styx did not visit all the blocks, but those it did could be reached by Charon and his servants.
Avalas touched the Astral Plane and had spherical portals to the three adjacent planes: Nirvana, the Nine Hells, and Concordant Opposition. The portals hung at fixed locations in space and would pass harmlessly through the blocks, becoming inactive while inside a block and reactivating when they reappeared. Anyone emerging from a portal would start to fall toward the nearest block and almost certainly required some form of flight to avoid a high-velocity impact. The portals were activated by touch and the destination could be determined by the sound it made when activated. A harmonious chord indicated a portal to Nirvana, a dissonant chord meant the Nine Hells, and silence indicated Concordant Opposition.
Of all known layers of Acheron, Avalas contained the largest number of cubes, which ranged in size from cities to continents. The layer was also the most densely inhabited of the plane.
Collisions between cubes were constant, happening as frequently as once a week and sending resounding vibrations throughout the layer. The collisions also slowly eroded the cubes, destroying structures on the surface, carving canyons, and collapsing tunnels. Due to the very orderly nature of the plane, the cracks on the cubes' faces were always perpendicular, so large cubes always broke down into smaller cubes. For that reason, smaller cubes were typically the oldest, while larger ones were younger.
The layer was continuously replenished with new, featureless cubes that were generally avoided by other cubes' inhabitants due to their lack of food sources and places to hide in the event of a collision.
The Styx crisscrossed the layer, emerging from a crater on one cube, running for miles, draining down into another crater, and reappearing on a different cube entirely. Sometimes, it changed course and drowned whole cities, taking with it memories and lives. In other places, the river flowed through one cube's face only to plummet into another in massive―and deadly―waterfalls.
NOTABLE CUBES

• The Blue Cube, the lair of the solitary blue dragon Teslor.
• Reizmis, a cube located near the entry point of the Styx into Avalas. The river completely engulfed the cube in a waterfall, causing its material to rust and absorb some of its memory-stealing properties. The Doomguard held a mining facility deep within the cube, where they used the metal to forge consumptive burst weapons infused with negative energy.
• Wreychtmirk, a cube along the Styx course that allowed travelers to accurately predict the river's destination. The Styx flowed from each of the cube's faces into a specific Lower Plane, causing each face to assume the plane's characteristics, so a passenger always knew where the river led from each face.

THULDANIN
This layer was the Sargasso Sea, Elephants' graveyard, and scrap heap for countless contraptions, creations, weapons, armour, failed experiments, broken devices, fallen buildings, and shipwrecks of sea and air. The blocks of Thuldanin were hollow and pockmarked with pits that lead to the interior a few miles/kilometres down. There the flotsam and jetsam of the ages turned to stone in a matter of days or weeks due to the magic of this layer. Thuldanin had no inhabitants, only the occasional visitor from Avalas looking for some piece of magic or technology that might turn the tide of battle.
Thuldanin had no inhabitants, except for the duergar. Other than this, there was only the occasional visitor from Avalas looking for some piece of magic or technology that might turn the tide of battle.
NOTABLE CUBES

• The Mines of Marsellin, a well-known mining site.

TINTIBULUS
It was the third layer of Acheron. It was mostly deserted expanse of loudly colliding boulders of different shapes and sizes, which often attracted magical researchers for its remoteness and isolation.
The third layer of Acheron had blocks different from those of the other layers. Here the blocks were made of grey volcanic stone and the faces were six-sided, eight-sided, or even higher in a number of edges. When the blocks of Tintibulus collided the surfaces would fracture along natural fault lines into hexagons great and small. This layer had no inhabitants but was attractive to magical researchers for its emptiness and isolation.
Unlike the top layers of Avalas and Thuldanin, the blocks of Tintibulus were not exclusively shaped like cubes. Rather, regular solids of other shapes were often found floating in the layer, with eight- and twelve-sided blocks being common, although any number of sides was possible. The solids were composed of gray volcanic stone, coated with a layer of ash-like dust of varying depths.
Collisions were frequent throughout the layer, carving hexagon-shaped crevices on the solids along naturally occurring fault lines and breaking the solids up into smaller shapes. Those collisions produced a constant ringing sound that could be loudly heard across the entire layer, in many cases impairing communication.
NOTABLE LOCATIONS

• The Hopping Tower, an ancient tower constructed by spectres and occupied by the insane wizard Lysander, a former Sensate who had developed many different spells that drew on the power of Acheron and the Quasi-Elemental Plane of Radiance.

OCANTHUS
The blocks of the fourth and final layer were square and so razor-thin as to be almost two-dimensional. An infinite and perpetually dark expanse. They ranged in size from a few inches/centimetres to several miles/kilometres across. Both sides of the hard black squares had normal gravity pulling to the surface and could be walked upon. Being hit by the edge of one of these razor-sharp squares could be deadly.
Ocanthus had an icy cold atmosphere of breathable air. However, the raging storm of shards in Ocanthus was extremely dangerous. They were as sharp and possessed the same ability to decapitate creatures as vorpal blades.
Some of the shards were large enough to generate their own gravity and to support structures. They all originated from a seemingly infinite boundary of black ice located at the bottom of the layer. It was believed that all shards were chipped away from this boundary, and successive collisions broke them down progressively into smaller shards, then needle-sized pieces, and finally to dust.
RUMOURS & LEGENDS
The exact nature of the endless black ice at the bottom of Ocanthus was largely unknown. It was debated whether it was a true boundary or just a barrier between the layer and some deeper, unknown fifth layer of Acheron. Others maintained that it could be just one more enormous shard-like the others, but whose boundaries were unknown.
It was said that the black ice was either the destination or the source of the River Styx. The ice was rumoured to hold all the lost memories that were stolen by the river. In addition, such memories were even said to be easily accessible by as simple an effect as a knock spell.
There were very few inhabitants that could survive the hazards of Ocanthus. Besides the small population of bladelings in Zoronor, the layer was also home to inhabitants from Mechanus who operated mining colonies in some of the shards.
NOTABLE LOCATIONS

• Zoronor, also known as theCity of Shadows. A mostly deserted city inhabited by bladelings.

INHABITANTS

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The main inhabitants of Acheron were the spirit legions occupying Avalas. They were made up of the spirits of humans, dwarves, halflings, ogres, and many other mindless soldiers who died in wars after forgetting their purpose; those for whom war became an end in itself. The spirits would congregate with others of similar beliefs or alignment and form nations on the surface of a block. They would fight to control a block and then join forces to conquer another block when it came within their reach. Legion members who were slain in battle would return with full strength within 24 hours, ready to fight again. The orc and goblinoid spirit legions shared the same large block in Avalas and besieged one another regularly.
Other creatures that could be found in Acheron were wandering imps, rust monsters, achaierai, and occasionally devils and modrons.

Type

Dimensional plane