True Damage
Damage that ignores physical and magic defense entirely.
True damage bypasses both physical and magic defense calculations completely, only reduced by explicit 'damage reduction' effects, which can even shave off true damage. Retribution's monster damage and execute-style effects (scaling with missing HP) are the most common sources, along with certain hero passives. True damage is the hard counter to stacked-defense tanks, since raw armor stacking provides zero mitigation against it.