Mutation resistance

Version 0.29: 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. Different sources of mutation resistance generally stack additively.

Sources

• You may acquire the Mutation Resistance mutation. It has three ranks: at ranks 1 and 2, 66% of attempts to mutate you will be blocked. Additionally, at rank 2, 50% of attempts to remove mutations will fail. At rank 3, you can neither add nor remove any more mutations: they are fixed. The only way to change this is divine intervention: Wrath from Jiyva, Xom, and Zin may remove it, and mutation gifts from the former two bypass resistance.
• Two unrands, the Hat of the Alchemist and the Lajatang of Order, provide mutation resistance when equipped. This is a 66% chance, equivalent to the first rank of the Mutation Resistance mutation. Using both at the same time won't increase the resistance.
• Zin provides a piety/1.6% chance to protect against attempts to mutate you. Six stars of piety is a perfect defense against mutation attacks.
• Ashenzari provides immunity to mutations that would shatter a cursed item, like Horns with a cursed helmet.
• Being undead provides full immunity to mutation. Whenever you'd mutate, you rot instead, causing attributes to temporarily drop. Stat drain can be cured by gaining XP, a generally easier process. Ghouls, Mummies, and players under Necromutation are undead, though Vampires are never considered undead for this purpose.

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.