- Unit drain effectiveness is a percentage applied to life and mana returned by % Life Stolen and % Mana Stolen per hit, which is applied separately (and thus multiplicatively) to difficulty level penalties applied to players and mercenaries: 50% drain effectiveness results in life and mana returned to players and mercenaries being reduced to ~1/4 in Nightmare (1/2) and ~1/6 in Hell (1/3).
- Does not apply to life returned by Life Tap.
- All mercenaries always have 100% drain effectiveness.
- Following pets always have 100% drain effectiveness:
- All other pets have 0% drain effectiveness.