Transmutation is one of the ways of acquiring mods. Choosing this Mod Action, players can sacrifice four selected unranked mods to generate a random mod from a list of mods that can be acquired in this way. Alternatively, three selected mods and one Transmutation Core can be used to guarantee a random mod of a specific polarity. Transmutation of Riven Mods requires a Riven Transmuter. Mods that cannot be acquired by transmutation are conventionally called untransmutable mods.