Rot
Rot is a status affliction that works like poison, but damages your maximum HP. The status itself is temporary, but the damage it inflicts is permanent until it can be corrected.
All undead, nonliving, demonic, holy, and insubstantial species and monsters are immune to rotting attacks. This also makes them immune to sickness and miasma. (Ghouls' periodic rotting and undead rotting-instead-of-mutation effects ignore rot resistance.) Zin's Vitalisation, Statue Form and Necromutation also grant immunity to rotting attacks, and demonspawn with the Foul Stench mutation gain rot resistance.
Sources of Rot
The rotting status can be inflicted by:
- Miscasting Necromancy spells (and by extension, possibly from Zot traps, Hell effects, and acts of Xom)
- Attacks from necrophages, death oozes, ghouls, or rotting devils
- Advanced mummies' death curses may inflict rot.
Certain other effects can cause max HP to be drained instantly, without inflicting the rotting status:
- Quaffing a potion of decay. Also, drinking from a sparkling fountain) may instantly inflict as much max HP loss as if you had quaffed a potion of decay and allowed the rot status effect to run its course (4.4% chance per attempt).
- Ghouls periodically lose max HP, with a greater chance if they are hungry. They can restore current and max HP by eating meat, preferably rotten.
- Standing in miasma without rotting resistance (undead or Zin) has a 50% chance to drain 1 max HP every turn you do so. It also poisons and slows you. Poison resistance only protects against the poison effect.
- Mutation on the undead (mummies, ghouls, lower-satitation vampires and lichform characters) causes decomposition, which rots max HP, as well as possibly draining stats. It can be blocked by an amulet of resist mutation with a 90% chance.
Curing Rot Damage
Rotting status can be cured with a potion of curing, or Elyvilon's "Purification" invocation.
The damage, once done, can be fixed by quaffing potions of curing or heal wounds while at your (new) full HP, or by invoking Elyvilon's purification. A potion of curing restores exactly 1 rotted HP. A potion/wand of heal wounds restores 2-7 rotted HPs (though a non-satiated Vampire quaffing a potion will get only half the effect). Ghouls can restore rotted HPs by eating meat, preferably contaminated or rotten. Mummies, who cannot consume potions, must rely on wands of heal wounds and their Self-Restoration ability.
History
Crawl used to have a "rotting" spell, which caused the flesh of all those near the caster to rot. It affected the living and many of the corporeal undead.
