Penetration
A stat that reduces an enemy's effective defense, sourced from the attacker's items.
Penetration lowers a target's effective physical or magic defense from the attacker's side — as opposed to a defense-reduction debuff applied directly to the target — and comes from items like Malefic Roar (physical) or Divine Glaive (magic). Flat penetration is strongest against low-defense targets, while percentage penetration scales better into high-defense tanks, which is why anti-tank item choice depends on how much defense the enemy has stacked. Building penetration is the standard answer once a team starts stacking defense against your damage dealers.