User:Lapis413

Impurity is a mechanic in dNethack, primarily used by the experimental Undead Hunter role, but accessible by anyone. The information in this document is current as of 10/26/24, and is subject to change.

Impurity is inspired by the Shinto concept of Kegare, representing how tainted you are by your actions and the things that have happened to you. As you accumulate impurity, certain blood-related effects become more potent, as well as a few other small effects.

Gaining Impurity

Impurity is gained either by performing *or being subject to* certain spiritually immoral actions. Whether you are victim or perpetrator does not matter; both are tainted.

There are 18 categories of exposure. Most of them allow 3 points of impurity to be gained from them. These work on a counter system: when an impure action is performed, a die will roll against your current counter. Beating that roll will increment the counter. Impurity is increased when the counter reaches 1, 4, and 15. This translates to needing only one exposure for the first point, roughly 7 for the second point, and around 120 exposures for the third.

Impurity type	Causes
Meat	Meat impurity is, naturally, gained by consuming meat. Anything that breaks vegetarian conduct should count for this.
Blood	Blood impurity is gained by using or being attacked by vampiric attacks, quaffing blood, scrawling in blood as a vampire, and using some weapons, such as the alternate form of the chikage. It is NOT currently raised by drawing or transfusing blood, but is intended to.
Bodies	Body impurity is gained by picking up corpses, or being attacked by skeletons or zombies (the bodies are handling YOU)
Death magic	Death magic impurity is caused by using or being affected by death magic. This includes wands of death and finger of death, as well as being subject to the killing touch of a lich. It is also increased by the drain life spell and wand. This still applies even if you resist or survive.
Great Old One Transcendence	Transcendence impurity is caused by witnessing a Great Old One survive death. This is most commonly from the major insight bosses shedding their mask as they die, but can also trigger off of Cthulhu reviving or the Masks madness. This is the only impurity counter that can go above 15, and is able to gain up to 6 points of impurity. This requires an impractically large number of exposures.
Theft	Theft impurity is gained by having your items stolen or using stolen items. This definitely works with consumables, but it's unclear what this means for a stolen weapon, armor, or tool. It also applies when you steal someone else's items through methods like yuki-onna natural theft.
Murder	Murder impurity is gained by committing murder. Keep in mind the dNethack definition of murder is broader than vanilla (peaceful intelligent monster of any type)
Bloodlust	Bloodlust impurity is gained by lowering your alignment record. This includes, for the moment, using golden scrolls of law.
Graverobbing	Graverobbing impurity is gained by digging up graves.
God Anger	God Anger impurity is gained by angering any god, including moloch (such as by attacking the priests in the temple of moloch)
Illness	Illness impurity is gained by either gaining Severe Illness or Food Poisoning.