Mask of Death, Mask of Madness, Helm of the Dominator and Satanic have the ability “Lifesteal” which, as its name suggests, steals some of the attacked target’s life and adds it to the Hero’s own with no other effects. Here are some important points on lifesteal:
– The amount of life stolen is based on the damage done to the target after armor reduction. Therefore, Critical Strikes will cause the attacker to steal extra life for that attack, and abilities that reduce armor such as Assault Cuirass’s armor reduction aura and Weave will cause the attacker to steal more life.
– You only lifesteal from the main target, never from units that got hit by Cleave, Splash, Moon Glaives or Split Shot.
– Lifesteal does not work on illusions, even though the graphics may suggest so.
– As far as orb effects are concerned, lifesteal overrides all other item orb effects. (Except ranged eye of skadi slow which is actually a buff not an orb. i.e. lifesteal and eye of skadi work together perfectly on ranged hero)
– For those who don’t know, if you got two orb lifesteal items, only one will work. The item in the highest priority slot will override the other. Primary priority is highest row, secondary priority is left over right.
– Also note that while Vampiric Aura[Skeleton King] and Vladmir’s Offering are similar to lifesteal and follow all the rules of the orb effect Lifesteal, they themselves are Auras and not orb effects, and can stack provided they give different debuffs to the target. Similar is Lifestealer’s Feast which stacks with everything.