Resistance

Version 0.29: 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 six "major" resistances. These are commonly granted by items, spells, or species-specific or random mutations:

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

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

• Fire/Cold resistance: 3 levels of resistance and vulnerability. Any level of vulnerability increases damage done by 50% from missile attacks and 100% from melee attacks and clouds. All player sources of resistance/vulnerability stack.
• Negative Energy resistance: 3 levels of resistance, no vulnerability. All sources stack, and rN+++ provides complete immunity.
• Electricity: 1 level of resistance, no vulnerability (see below). Level gives 66% damage reduction.
  • Followers of Qazlal can get 1 level of shock vulnerability if they get under penance.
• Acid resistance: 1 level of resistance, no vulnerability. Level gives 50% chance to resist corrosion and 50% damage reduction.
• Poison resistance: 1 level of resistance and vulnerability. rPois does not stack, though any amount of poison resistance and poison vulnerability cancel each other out.
  • Poison Immunity: rPois∞, a full immunity, is obtained via species, an unrand, or special forms. Unable to be vulnerable.

Damage reduction

Monsters and players with resistance will take less 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 and miasma. Note that players can only gain 1 level of rElec / rPois / rCorr from natural means. Certain forms and monsters may have more.

The damage reduction for players (except for negative energy) is:

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

Monsters' resistance is more effective:

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

Negative energy is handled differently:

rNeg	0	1	2	3
Players	100%	66%	33%	0%
Monsters	100%	0%	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) rings.
• 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.

• Steam resistance from steam dragon scales. Fire resistance will also grant some resistance to steam.
• 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 immune to damage from holy or damnation, that is not available for players.

History

• Prior to 0.26, rot resistance existed.
• 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. rElec was also changed to reduce by 66%.
• 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 armour, 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.