Mutation resistance

Version 0.28: 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: Jiyva, Xom, and Zin's wrath may remove it, and the former two's mutation gifts 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.
• Being undead makes it so that you will rot instead of mutate, causing drops in your attributes. In general, this is easier to cure than mutations. Vampires don't function as undead in this aspect, and will mutate normally. Necromutation can allow most players to become undead.

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 0.27, 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.