At the center of Arcanum lies a region that truly belongs to no known kingdom.
A colossal abyss, ancient and deep, whose limits have never been found. No one knows for sure when it appeared.
Some believe the Abyss was born alongside Arcanum, a flaw left behind when the world was formed. Others claim it was created later, when something too powerful had to be removed from the surface. And there are those who defend a more unsettling hypothesis:
The Abyss was never created.
It was always there.
For ages, however, its passages remained sealed. Gates, ruins and structures raised around its depths suggest that ancient peoples knew the danger below, and did everything they could to keep it from reaching the surface.
The seals held for a long time.
Until they began to fail.
The World Beneath Arcanum
The Abyss is not just a deep cave.
The deeper you go, the less its structures obey Arcanum's natural laws. Tunnels lead to places that shouldn't fit underground. Ruins appear at depths where no known civilization could have existed. Dark horizons can be seen where there should be only rock.
Some scholars believe there is an entire world beneath Arcanum.
Others suspect there are several.
Surface
The kingdoms, forests, cities and creatures of Arcanum
Decay
Everything that is lost, forgotten, corrupted or rejected
Abyss
A lower world formed by the build-up of that decay
The Abyss seems to grow from everything that decays in the worlds above it.
Not just bodies.
Forgotten memories, corrupted energies, abandoned desires, failed spells and fragments of creatures that ceased to exist seem to slowly sink into its depths. There, these remains don't disappear.
They pile up.
They transform.
And they learn to take on new forms.
That's why some arcanists describe the Abyss as the place where Arcanum sends everything it can't completely destroy.
The Birth of the Abyssals
The Abyssals are manifestations formed in the depths of the Abyss.
They are not a race with a shared origin, culture or lineage. Each Abyssal is the result of decayed energies that piled up until they gained matter, instinct and will.
Some are born from the remains of creatures consumed by the depths. Others seem shaped from emotions, memories or spells that rotted for centuries. There are even manifestations so old that no scholar can identify what gave rise to them.
The rise of an Abyssal is no ordinary birth.
Nor is it a traditional summoning.
It is decay learning to live.
In the early stages, these manifestations may show incomplete forms: limbs that fade into the darkness, bodies covered in unstable matter or faces that seem to belong to several creatures at once.
Over time, however, the Abyss's energy settles on a more defined form.
And what was once only decay begins to hunt.
The Reapers
Most known Abyssals manifest as Reapers.
They are creatures shaped to roam the depths, gathering whatever falls from the surface and carrying the remains to even deeper regions. It's unknown whether they fulfill a natural role of the Abyss or obey something that remains hidden below.
Their bodies vary, but certain traits show up often:
Elongated bodies
Thin, long or disproportionate frames, adapted to the deep passages.
Gathering limbs
Claws, blades, chains and appendages used to drag matter into the Abyss.
Unusual senses
They sense Anima, fear, death and decay even through stone.
Reapers don't hunt just to feed.
They gather.
Corpses, cursed objects, fragments of magic and creatures still alive can be taken into the depths. The fate of what is captured remains unknown, because almost nothing comes back.
And what does come back can no longer explain what it found.
An Ecosystem of Decay
Despite its chaotic appearance, the Abyss seems to have an ecosystem of its own.
The upper layers are home to lesser manifestations, drawn by the energy that escapes from the worlds above. In the deepest regions dwell ancient beings, adapted to concentrations of decay that could destroy an ordinary creature in moments.
The deeper you go, the less recognizable its inhabitants become.
Predators feed on arcane residue. Colonies grow over buried ruins. Smaller creatures live inside larger Abyssals, slowly consuming their energy until they emerge as new manifestations.
There are accounts of lightless forests formed by bone-like structures. Dark lakes that reflect places that don't exist. Entire cities built upside down above even deeper openings.
No one knows whether these regions were born inside the Abyss.
Or whether it swallowed them.
The Abyssal Leak
The Abyss stayed sealed for ages, but its seals are no longer perfect.
When its energy finds a passage, it begins to influence the surface. This phenomenon is known as the Abyssal Leak.
Ancient rifts, underground ruins and places marked by great concentrations of death are common leak points. The energy seeps out slowly, contaminating the soil, the water, the creatures and even the local magic.
When the leak continues, the changes stop being individual.
Whole regions can mutate.
Forests change shape. Caves grow in impossible directions. Buildings sink without the ground moving. Lesser Abyssal beings begin to appear nearby, signaling that the border between the two worlds is weakening.
The Abyss doesn't need to open completely to transform what lies above it.
It only needs to breathe through a crack.
Surface Mutations
Not every creature altered by the Abyss's energy becomes an Abyssal.
True Abyssals are manifestations born in its depths. Surface beings contaminated by that energy still belong, at least at first, to their original species.
That distinction, however, can fade over time.
Prolonged exposure changes flesh, consciousness and Anima. Some creatures develop unusual senses, new body structures or an inexplicable need to approach the rifts. Others slowly lose their natural traits until they become unrecognizable.
Brief exposure
Fever, hallucinations, behavioral changes and sensitivity to abyssal energy.
Prolonged exposure
Physical mutations, warping of the Anima and gradual loss of identity.
Deep contamination
The creature begins to act as an extension of the Abyss and may no longer recognize the world it belonged to.
Scholars still argue over whether this transformation has a limit.
Some believe a contaminated being never becomes a true Abyssal. Others argue that, given enough time, the Abyss completely replaces what the creature once was.
At that point, the difference stops mattering.
Those Who Go In
Explorers, scholars, arcanists and whole expeditions have tried to understand the depths of the Abyss.
Few returned.
None came back completely unharmed.
Some come back with altered bodies. Others keep their original appearance but show deep changes in behavior. They forget their own names, recognize places they've never been or spend nights describing landscapes that don't exist on the surface.
Some survivors claim they stayed inside only a few minutes, though they had vanished for years. Others swear they crossed entire cities over months and returned the same day they left.
The Abyss transforms everything that crosses its limits.
Flesh.
Memory.
Time.
Even those who escape bring something back.
And, in many cases, the creature that returns knows things it should never have learned.
What Remains Sealed
The ancient seals found around the Abyss were built with techniques from different eras and civilizations. Some are simple arcane barriers. Others use structures so complex that today's scholars can't reproduce them.
This suggests the Abyss was sealed more than once.
And by different peoples.
With each failure, new barriers seem to have been raised over the old ones, forming layers of containment around something that could never truly be destroyed.
The biggest question isn't what the seals keep from getting in.
It's what they keep from getting out.
The Reapers may be only the manifestations able to cross the upper regions. Older creatures may remain below, trapped not for lack of strength, but because they haven't yet found a passage big enough.
That's why every leak stirs fear among those who know the history of the depths.
A crack is never just a crack.
It's a path being opened.
Its Influence on Arcanum
Even sealed, the Abyss affects the world.
Its energy feeds mutations, alters natural regions and draws scholars eager to understand forces that exist nowhere else. Some arcanists believe it can be controlled and used as a source of power.
Others consider that idea a death sentence.
Abyssal energy doesn't respond like Anima, nor does it behave like Essence. It doesn't create from life.
It reshapes from what was lost.
Every use of this energy creates a link with the depths. The more someone wields it, the easier it becomes for the Abyss to recognize their presence.
And perhaps to look back.
Traits
- They are manifestations born in the depths of the Abyss.
- They don't form a single race, having different origins and structures.
- They arise from the decay of matter, Anima, memories and energies coming from the worlds above.
- Most of them manifest as creatures known as Reapers.
- They inhabit a possible underground world made up of countless regions and, perhaps, entire dimensions.
- They may show incomplete, shifting forms or forms incompatible with Arcanum's natural laws.
- The Abyss's energy causes mutations when it leaks to the surface.
- Contaminated creatures aren't necessarily Abyssals, but they can gradually lose their form and identity.
- Beings that enter the Abyss rarely return, and those who come back are never the same.
- Their existence suggests that something far older remains sealed in the lower regions.
The Abyssals are born from what the world has lost.
And beneath Arcanum, nothing stays lost forever.