Mutations vs. mutagens — the confusing part
These two systems sound alike but are different. Mutagens are red / green / blue items you slot into the character panel for flat bonuses to Attack Power, Sign Intensity or Vitality (and they boost more when grouped with skills of the same color). Mutations are a separate, deeper system added by the Blood and Wine expansion that unlocks powerful new passive effects and extra skill slots.
How to unlock mutations
Mutations require the Blood and Wine expansion. Once you start Blood and Wine, progress to the point where Professor Moreau's laboratory becomes available; the mutation menu then appears in your character screen. Each mutation must be researched there.
- Mutagens — Every mutation costs a set of red, green and/or blue mutagens — the same items you craft from monster mutagens.
- Ability points — Researching a mutation also spends ability points, so they compete with normal skills. Use a Potion of Clearance to respec if needed.
- One active at a time — You can research all of them, but only one mutation is active at once — swap freely outside combat.
The mutations and what they do
| Mutation | Effect |
|---|---|
| Euphoria | Every point of Toxicity raises your sword damage and Sign Intensity, up to a cap — the strongest endgame mutation for alchemy builds. |
| Piercing Cold | Aard gains a chance to freeze enemies — and frozen, low-health foes shatter instantly. The freeze chance scales with Sign Intensity. |
| Conductors of Magic | While a sword is drawn, your Signs deal extra damage equal to a share of the sword's own damage — scaling Signs off your weapon. |
| Toxic Blood | Each time an enemy injures you in melee, they take damage back in proportion to the blow they landed. |
| Mutated Skin | Each Adrenaline Point reduces incoming damage, up to a cap — a defensive staple for survivable combat builds. |
| Bloodbath | Fatal sword blows dismember enemies or trigger a finisher, and each hit stacks a damage bonus that grows as you cut through a crowd. |
| Second Life | When your Vitality reaches 0 you briefly become invulnerable and regenerate health — once per fight. |
| Adrenaline Rush | At the start of a fight your Attack Power and Sign Intensity spike for a few seconds, scaling with the number of foes you face. |
| Cat Eyes | Greatly increases crossbow damage and critical hit chance, turning the crossbow into a genuine weapon. |
| Magic Sensibilities | Your Signs can land critical hits, with critical chance and damage scaling off your Sign Intensity. |
| Deadly Counter | Counterattacks — and hits against counter-immune humans and monsters — deal heavy bonus damage, rewarding precise parry play. |
| Metamorphosis | Applying a critical effect activates a random decoction for a time with no Toxicity cost, letting you stack more decoctions at once. |
Extra skill slots
Each mutation you unlock also opens additional mutation skill slots branching from the four main trees. These let you slot more active skills than the base game allows, which is the main reason to chase mutations even before settling on a favorite.
Frequently asked questions
- What's the difference between mutations and mutagens?
- Mutagens are color-coded items that give flat stat bonuses in the character panel. Mutations are a Blood and Wine system that unlocks powerful passive effects and extra skill slots, researched with mutagens and ability points.
- Do you need Blood and Wine for mutations?
- Yes. The mutation system is exclusive to the Blood and Wine expansion and unlocks at Professor Moreau's laboratory after you begin the expansion.
- What is the best mutation in Witcher 3?
- Euphoria is widely considered the strongest for alchemy/Toxicity builds, raising both sword and Sign damage. Piercing Cold and Conductors of Magic are top picks for Sign-focused builds.
- Can you have more than one mutation active?
- You can research every mutation, but only one can be active at a time. You can switch the active mutation freely outside of combat.