Mutation resistance

Version 0.30: This article may not be up to date for the latest stable release of Crawl.

Mutation resistance (rMut) provides player a chance to avoid being mutated. Sources of this resistance stack multiplicatively.

Useful Info

Mutation resistance blocks incoming mutations from affecting you. Except for having the "Mutation Resistance" mutation, they don't block mutations from being removed.

God-given mutations (from Jiyva and Xom) ignore all mutation resistance except from 1. other divine sources or 2. being undead. Mutations from magical contamination have a 50% chance to ignore all non-undead resistance, including Zin's divine protection.

Sources

• The rMut item property (found only on Hat of the Alchemist and lajatang of Order) gives a 66% chance to block mutations. The item property does not stack with itself.
• The Mutation Resistance mutation can block mutations based on its level. Level 1 gives a 66% chance to block incoming mutations. Level 2 also gives a 50% chance to block mutations from being removed. Level 3 gives a 100% chance to block incoming or outgoing mutations (barring the above exceptions).
• Zin provides a piety / 1.6% chance to block mutations. At 6* piety, this is full immunity.
• Being undead (Ghoul, Mummy, Lich Form) provides full, absolute immunity to mutation. Instead, you "rot" when mutating, causing stat drain.

Also, Ashenzari provides immunity to mutations that would shatter a cursed item, like Horns with a cursed helmet. This applies to every source of mutation, including ones that Zin doesn't protect form.

Existing mutations

Existing mutations may block further mutations from effecting you.

• Each mutation you already have gives you 6.5% resistance against future random mutations. This ONLY applies to random mutations; bad mutations from enemy attacks still affect you normally.
• Any time you resist a random mutation through this method, you have a 33% chance of losing one of your mutations as well.

History

• Prior to 0.29, Ashenzari did not provide protection against mutations.
• Prior to 0.27, Halflings started with a level of mutation resistance.
• Prior to 0.21, Zin's mutation protection was 100% at 200 piety instead of 160 piety.
• Prior to 0.20, potions of cure mutation existed.
• Prior to 0.18, amulet of resist mutation existed.
• Prior to 0.15, vampire mutation effects depended on their satiation level.