"Damage" (ダメージ Damēji) is the primary way to reduce the player's life. It is dealt either by an attack, or by an effect that explicitly says "take/deal damage".
- The damage can be categorized as "dealt by an attack" or "dealt by an effect". This difference is necessary to activate certain cards or effects.
- If the damage that would be dealt is 0 by any reason or method, it is no longer considered as "being dealt damage".
- Paying a certain amount of life is not considered as "being dealt damage", so cards like Dragon Arms, Dragokeeper cannot reduce it.
- Cards saying "lose X life" is not to be considered as "being dealt damage", as well as cards that say "life becomes X".