Any attack the character makes of 12 Damage or more gains a number of additional Damage equal to the number of Knacks they have, including magical attacks.
Any attack the character makes of 12 Damage or more gains a number of additional Damage equal to the number of Knacks they have.
Purchasing this Knack multiple times only adds +1 to the additional Damage dealt.
Many weapons, such as warhammers, come with this Knack in-built, so anyone with the Knack: Finishing Blow, who also wields a warhammer, would trigger +2 Damage any time they dealt 12 or more Damage, or more if they had further Knacks.