Acid
Acid is a damage type most commonly dealt by jellies and acidic dragonkind, which can be resisted with corrosion resistance. Most types of acid damage can apply a temporary corrosion status, which lowers your AC and slaying.
Contents
Sources of Acid
Acidic damage can come from several sources:
Acidic Melee Attacks
The following monsters have acidic melee attacks, which deal acid damage and may apply corrosion:
J 
Jelly
Acid Spit
The following monsters can spit acid as a ranged attack, which bypasses AC and may incur corrosion:
P 
Oklob sapling: 3d7 (3d3)
P 
Oklob plant: 3d7 (3d6)
D 
Acid dragon:
J 
Acid blob: 3d7
d 
Yellow draconian: 3d7
Acidic Flesh
Some monsters have acidic flesh and will deal acid damage when attacked at close range:
J Jelly
Slime Walls
Standing next to the walls of the Slime Pits will cause players and non-jelly monsters to take damage, although it does not cause the corrosion status.
Worshipers of Jiyva are unaffected by slime walls.
Corrosion Resistance
Corrosion resistance reduces damage taken from acid and reduces the chance of being further corroded.
The sources of Corrosion resistance are:
- being a yellow draconian
- Ring of resist corrosion
- Acid dragon scales
- Tiamat's dragonskin cloak (50% chance per attack)
- Having the yellow scales mutation at level 3
- Having at least ** piety while following Jiyva
Damage Reduction
Players with corrosion resistance take 50% damage from acid. All monsters with any degree of acid resistance are completely immune to acid damage.
Corrosion
Corrosion is a temporary status effect which gives a stackable -4 to slaying and AC for as long as it lasts. Corrosion will be repaired after enough turns have passed. It can also be removed with Potion of cancellation or Purple Draconian's breath aimed at yourself.
In addition to taking acid damage, players may also suffer corrosion from these sources:
- The Entropic Weave spell of B
Entropy weavers - Taking damage when wearing an artefact with the *Corrode property.
Monsters that have been corroded simply get a temporary -8 to their AC.
History
Prior to 0.15, corrosion instead caused permanent damage to weapons and armor, reducing their enchantment values, possibly into the negatives. Also, potions of resistance did not grant rAcid or rCorr. There were previously three tiers of acid resistance, each one further reducing acid damage; now there is only one level which is merged with corrosion resistance.
