Lifesteal

Lifesteal allows the attacking unit to gain Health when damaging an enemy with a regular(right-click) attack, which includes any attack modifier with physical damage. The lifesteal ability can be gained via items, passive abilities or the auras of other units.

The amount of health a unit gains from lifesteal is calculated by percentage of the actual damage done to the damaged unit.

Lifesteal Unique Attack Modifier
Lifesteal as a Unique Attack Modifier is the most common form of lifesteal and can be used by both melee and ranged units. With the exception of Satanic's Unholy Rage ability, they are all passive abilities. Items that give this type of lifesteal are:



These items do not stack with each other. The one in the highest priority slot will override the others.

Lifesteal Aura
Lifesteal granted by an aura gives certain units in the area of effect the lifesteal ability. Lifesteal auras will stack with other lifesteal auras, but not with identical lifesteal auras. Lifesteal auras will stack with lifesteal granted by Unique Attack Modifiers. Items and skills that provide a Lifesteal Aura are:



Lifesteal and other Abilities

 * Critical Strike: Lifesteal is calculated after Critical Strikes, which means that it will increase the amount of life you steal.
 * Bash: Only bashes that deal physical damage will grant lifesteal.
 * Lifesteal will only work on the main target of the attack, abilities that cause an attack to hit more than one target (e.g. Cleave, Splash or Moon Glaive) do not add extra lifesteal, despite what the animation might show. The only exclusion to this rule is with Rubick. If Rubick steals Insatiable Hunger and then steals Flak Cannon, for the next 3/4/5/6 attacks, Rubick will have 60/80/100% life steal from everything around him.
 * Illusions do not benefit from lifesteal or lifesteal auras, although they perform the animation.
 * Lifesteal will not work on abilities even if they do physical damage.
 * Unique Attack Modifiers: With the exception of Orb of Venom and Eye of Skadi, lifesteal from orbs will not stack with other orbs.

Triggered Lifesteal
Certain lifesteal effects were written as triggered effects in the original Warcraft III engine. While such nuances are moot as of Dota 2, the following spells still behave differently than other lifesteal effects:


 * Feast is written as two independent effects. The damage is reduced by armor, but the heal to Lifestealer is not. Therefore, the heal cannot be increased with damage bonuses such as critical strike. Lifestealer's physical attack damage (including the bonus damage from Feast) can still benefit from other sources of lifesteal.
 * Open Wounds is unique in that it will grant allies lifesteal on the target. All damage dealt can grant lifesteal, including magical damage from spells. This is the only way ability damage can grant lifesteal. (regardless of skill's damage type)
 * Feast is written as two independent effects. The damage is reduced by armor, but the heal to Lifestealer is not. Therefore, the heal cannot be increased with damage bonuses such as critical strike. Lifestealer's physical attack damage (including the bonus damage from Feast) can still benefit from other sources of lifesteal.
 * Open Wounds is unique in that it will grant allies lifesteal on the target. All damage dealt can grant lifesteal, including magical damage from spells. This is the only way ability damage can grant lifesteal. (regardless of skill's damage type)
 * Open Wounds is unique in that it will grant allies lifesteal on the target. All damage dealt can grant lifesteal, including magical damage from spells. This is the only way ability damage can grant lifesteal. (regardless of skill's damage type)
 * Open Wounds is unique in that it will grant allies lifesteal on the target. All damage dealt can grant lifesteal, including magical damage from spells. This is the only way ability damage can grant lifesteal. (regardless of skill's damage type)
 * Open Wounds is unique in that it will grant allies lifesteal on the target. All damage dealt can grant lifesteal, including magical damage from spells. This is the only way ability damage can grant lifesteal. (regardless of skill's damage type)

PD: This is wrong, you can technically lifesteal with bloodseeker's first skill, but im too bored to edit this properly. Please someone do it. PD2: If that ^ is wrong, its still like the old bloodseeker ability which healed BS for a percentage of the Max HP of any killed unit.