Corruption

If you encounter a corrupting influence, you gain Corruption based on the severity of the exposure you experience. You may resist some or all of the Corruption with a Fortitude or Discipline Test, as determined by the GM — usually physical influences are resisted with Fortitude, and spiritual corruption is resisted with Discipline. On a success, you may reduce the Corruption you gain by your SL, to a minimum of 0.

Minor Exposure

(1 Corruption)

These relatively weak corrupting influences still endanger a feeble soul. Examples include:

• Witnessing a Lesser Daemon.
• Reading a few pages of a profane tome.
• Contact with a Chaos Mutant or Chaos tainted artefact.
• Momentarily giving in to a powerful emotion tied to a Chaos God, such as despair (Nurgle), rage (Khorne), excess (Slaanesh), or curiosity (Tzeentch).
• Prolonged exposure to Chaos worshippers, Chaos Temples, Mutant Lairs, and similar.

Moderate Exposure

(2 Corruption)

Moderate corrupting influences are a danger to every soul and should be avoided under all circumstances. Examples include:

• Witnessing multiple Daemons.
• Contact with a Daemon or profane artefact.
• Embracing a powerful emotion tied to a Chaos God, such as despair (Nurgle), rage (Khorne), excess (Slaanesh), or curiosity (Tzeentch).
• Brief exposure to a place where a Chaos ritual was held.
• Reading a profane tome.

Major Exposure

(4 Corruption)

If confronted with a major corrupting influence, flee. Stay for too long, and you may never be the same again. Examples include:

• Witnessing a Greater Daemon.
• Taking the time to truly study or obsess over a profane tome.
• Prolonged contact with a Daemon or profane artefact.
• Making a deal with a Daemon.
• Prolonged exposure to an environment steeped in warp energy.

As corruption ravages your soul, the warping breath of Chaos whispers within, either fanning your flesh into a new form, or fracturing your psyche with exquisite knowledge it can never unlearn. Corruption expresses itself as Mutation and Malignancy. Mutations are unnatural changes to the Human body. Malignancies are akin to mutations of the mind. They are insidious, drawing one into ever more extreme positions and unwelcome insights, eventually leading down the path to damnation.

Should you ever gain more Corruption than your Willpower Bonus plus your Toughness Bonus, you are in danger of succumbing to Chaos. During the next adventure (at an appropriate point determined by your GM), attempt a Challenging (+0) Fortitude (TGH) or Discipline (WIL) Test. If successful, you have managed to hold off your corruption for now, but will have to Test again the next time you gain Corruption. If you fail, then either your body or mind changes profoundly and unnaturally.

Dissolution of Body and Mind

When you fail a Test to resist succumbing to your Corruption, you first remove Corruption equal to your Willpower Bonus. Next, roll 1d10. If the result is an even number, roll 1d100 on the Mutations Table; if odd, roll on the Malignancies Table. You gain the resulting Mutation or Malignancy.

If you would gain a Mutation or Malignancy you already have, reroll on the table until you receive a result that you don't have.

[Warr's Note: whatever changes I do end up making to the corruption mechanics will likely end up centring the above point, as well as foregrounding the socio-political aspect of "corruption" and "mutation" (see Pellenne's lore for an in-universe example).]

Limits of the Soul

A soul can only withstand so much corruption before it collapses upon itself, leaving a mutated, gibbering mess. Should you survive long enough to gain more Mutations than your Toughness Bonus, or more Malignancies than your Willpower Bonus, you have completely fallen to Chaos, your soul lost to the Dark Gods. At this point, your body utterly succumbs to the mutating force of the warp, and your mind shatters into countless fragments. Your character becomes a Chaos Spawn under the GM’s control. There is no salvation from such a fate — make a new character.

Once the claws of the Dark Gods have sunk into your soul, removing their vile stain is difficult, but not impossible. Beyond the less-than-desirable option of losing Corruption by gaining mutations, some do manage to claw their way back from the edge. Those seeking to purge themselves and atone for their misdeeds may seek Absolution.

Absolution

As Corruption builds and you feel the oppressive fist of the Ruinous Powers curling around your soul, dread may lead you to seek absolution. But simply asking forgiveness from a local preacher won’t be enough. The stain of the Dark Gods’ touch isn’t so easily scrubbed clean. The exact limits of what is required to remove Corruption is left in the hands of the GM, but it is rarely, if ever, simple. Examples include:

• Make a pilgrimage to Thaur, Ossuar, or a similarly sacred location.
• Cleanse a desecrated shrine.
• Destroy or cleanse an unholy artefact.
• Seek out and destroy a Traitor Astartes.