Resistance

Version 0.18: This article may not be up to date for the latest stable release of Crawl.

For the ego found on robes and shields, see resistance (ego).

Monsters and players may have resistances against various types of damage; these are a subcategory of intrinsics.

Types of resistance

There are five "major" resistances. These are commonly granted by items, spells, or species-specific or random mutations:

• Fire resistance
• Cold resistance
• Negative energy resistance (aka life protection), which is resistance against draining attacks, necromantic magic, etc.
• Electricity resistance
• Poison resistance

The degrees to which characters may have resistance to these elements vary from resistance to resistance:

• Fire/cold resistance: can vary from rF/rC--- to rF/rC+++. Having any level of vulnerability increases damage done by 50% from missile attacks and 100% from melee attacks and clouds, but a character with rF--- will take no more damage from fire attacks than a character with rF-. All player sources of resistance/vulnerability stack.
• Negative energy resistance: can vary from none to rN+++. All sources stack, and rN+++ provides complete immunity. Vulnerability does not exist.
• Electricity resistance: Player can only have one level, rElec, which provides 66% damage reduction. Vulnerability does not exist, and sources do not stack.
• Poison: The player can have four levels: rPois-, none, rPois, or rPois∞. Vulnerability is obtained by being in Spider Form, being under the effects of the Virulence spell, or from artefacts with rP-, while immunity (rPois∞) is obtained by being undead or a Gargoyle, including being in Lichform or Statue Form. Sources of rPois do not generally stack, with one exception: poison vulnerability and poison resistance will cancel each other out to leave a character with no resistance.

Damage reduction

Monsters and players with resistance will take less damage (or no damage) from a resisted attack. Some attacks are only partly resisted – for instance, only 45% of the damage from Fire Storm will have resistance (or vulnerability) applied to it.

Resistance is more effective vs. Sticky Flame, electrical attacks, and miasma.

The damage reduction for players is:

Player Resistance level	Damage taken	Dam. vs. sticky/elec./mias.
1	50%	33%
2	33%	25%
3	20%	17%

Note that players can only ever gain one level of electricity resistance. Monsters, however, can have more than one.

Monsters' resistance is more effective:

Monster Resistance level	Damage taken	Dam. vs. sticky/elec./mias.
1	50%	33%
2	20%	17%
3	0%	0%

It is also possible for the player to be vulnerable (i.e., to have negative resistance) to fire, cold, or poison. Monsters can be vulnerable to fire, cold, poison, and electricity, and evil creatures (including the player, if undead, demonspawn, or in lichform) are vulnerable to cleansing flame. Vulnerability (of any degree) causes a creature to take 150% normal damage from missiles and 200% damage from all other attacks.

Life protection is handled differently: each level reduces damage taken by a third, meaning level 3 provides total immunity to draining and necromancy. Torment is also resisted by life protection, using yet another formula.

Gaining Resistances

• Quaffing a potion of resistance will give you one level of fire, cold, electricity, corrosion and poison resistance for a while.
• Various dragon scales, as well as other ego armour, will provide various major or minor resistances if worn.
• Most resistances (not electricity) can be gained by wearing particular (standard) items of jewellery.
• Artifacts may provide one or more resistances, including electricity resistance and some of the "minor resistances" below.
• All major resistances can be gained through a corresponding mutation (although only demonspawn can gain the life protection mutation).
• Some species have racial resistances or vulnerabilities. Notably, all the playable undead races have at least Cold Resistance 1, Life Protection 3, Poison Resistance, and Immunity To Torment.
• Many spells in the Transmutations school provide assorted resistances along with their other, more dramatic effects.

Minor Resistances

There are also a few "minor" resistances which come from specific items or species characteristics.

• Acid resistance protects you from acid damage and gives you a 50% chance to resist each instance of corrosion. It can come from a ring of resist corrosion, wearing acid dragon scales, being a yellow draconian, rank 3 of the Yellow Scales mutation, some randarts, the unrands Maxwell's patent armour and Punk, or having at least *** piety with Jiyva.
• Steam resistance from steam dragon scales. Fire resistance will also grant some resistance to steam.
• Rot resistance comes from being undead (including being in lich form). It does not protect ghouls against their own random rotting, and all undead will rot instead of mutating. Vine stalkers, characters in Statue Form, and demonspawn with the Foul Stench mutation also receive rot resistance. Rot resistance also confers resistance to sickness and immunity to miasma.
• Torment resistance will reduce damage from monsters casting Symbol of Torment or when using a scroll of torment. Being undead or in Dithmenos's Shadow Form provides full resistance, following Kikubaaqudgha will sometimes prevent torment damage, and having the Hurl Damnation demonspawn mutation, being a gargoyle, or being in Statue Form each reduce torment damage by half. All other adventurers must rely on mitigating torment damage with negative energy resistance.
• Mutation resistance comes from the mutation of that name, the unrandarts Hat of the Alchemist or Lajatang of Order, or high piety with Zin. The unrandarts and ranks 1 and 2 of the mutation have a 66% prevent you from mutating, while Zin's protection scales with piety, reaching 100% at maximum. Rank 3 of the mutation also provides 100% protection from mutations (as well as mutation removal). Additionally, having previous mutations may allow you to resist gaining new ones (though that may remove some of them in the process). Undead will always rot instead of mutating, but mutation resistance will block that rotting with the same frequency it would block mutation for a living character.
• A few other intrinsics act like specialized resistances: clarity (confusion, frenzy, sleep, mesmerization), stasis (slow, teleport, paralysis, haste)
• Although some monsters are resistant to damage from damnation and tornado, these resistances are not available for players.

History

• In 0.18, the amulets of resist mutation, stasis, and clarity were removed and the amulet of resist corrosion became a ring. Additionally, mutation resistance from now on only provides a 66% chance to avoid mutations.
• Prior to 0.17, sustain attributes was named "sustain abilities", and corrosion reduced slaying and AC by 3 and 5 respectively instead of giving -4 to both.
• Prior to 0.15, wearing a cloak of preservation was the usual choice to prevent item destruction. The concepts of item destruction and permanent corrosion effects retired at the same time. 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.
• Racial equipment variants were removed in 0.14, so is gone corrosion resistance of anything of dwarven make.
• Elemental (Fire, Cold, and Electricity) resistances for players were nerfed in 0.6.
• Poison resistance for living characters was nerfed to provide only 90% protection against poisonous melee attacks in 0.10.