What is lifesteal?

Lifesteal is the name given to some skills that allow you to earn HP by dealing attack damage to other units, there are several types of these skills, but they are divided in 3 groups.


Lifesteal (Orb Effect)

This is the most common type of lifesteal , it’s separated from the rest because it’s considered an Orb Effect (non-buff placer) on melee and ranged units, it’s one of the orb effects with highest priority, as it overrides most of the other orb effects with one exception, Incinerate.

Items or Skills

• Mask Of Death (15% air,ground,enemy)
• Helm of the Dominator ( 15% air,ground,enemy)
• Mask Of Madness (17% air,ground,enemy)
• Satanic (not Activated) (25% air,ground,enemy)
• Satanic (Activated) (175% air,ground,enemy)

If you have more than two of these items the one in the highest priority slot will override. Satanic's activable will completely overried it's passive.

Aura Based Lifesteal

This is the kind of lifesteal that comes from the Vampiric Aura skill, it shares almost all the same characteristics as the previous skills, but it’s not an orb effect and it can only be used by melee heroes.

Items or Skills

• Vampiric Aura (15%/20%/25%/30% with 900 area of effect, affects allied and self owned organic units)
• Vladmir's Offering (16% on a 1100 area of effect, affects allied and self owned organic units )
• Insatiable Hunger (40%/60%/80% self only)

These skills stack additively with each other, but they will not work with themselves, this is because they all place a buff on the attacking.
For example you can have Vladmir’s on Leoric with Level 4 Vampiric Aura, giving you a total of 46% Lifesteal, but if you buy another Vladmir’s the amount will remain, since the second Vladmir’s not being able to place it’s buff on an already buffed unit.

Interactions between Orbs and Auras

They are independant of each other, the amount of lifesteal percentage can be calculated by simple addition of the individual values of the overriding orb and the buffs coming from auras that the unit has.

Damage

Lifesteal from Orb and Auras comes pretty much after all the reductions you can think of (Mana Shield, Damage Block, Armor Type and Armor Amount reduction) making it quite weak, there are some special interactions which will be mentioned here:

• Critical Strikes: Lifesteal is calculated after Critical Strikes, which mean that it will increase the amount of life you steal.
• Bashes: Melee bashes will work normally. Ranged Bashes add damage directly to your attack, thus you will lifeleech from it.
• Triggered Heals: The amount reduced by triggered heals will be considered as pre-lifesteal reduction.
• Skills that damage more than one target: Namely Cleave, Splash and others; As a general rule, lifesteal will only work on the main target of that attack, despite the animation showing something different.

Triggered Lifesteal

This is sometimes called “Pseudo-lifesteal” since it’s really a triggered attempt to reproduce the ability with some changes.
The only current skills that fall in this category are Feast and Open Wounds.

• Feast (recovers 4%/5%/6%/7% of the target’s current life on attack.

The damage dealt by feast is a separate instance of damage that can be reduced by armor type and quantity, it should be noted that this type of lifesteal will not be directly affected by any attack modifiers, incuiding Critical Strike.

• Open Wounds (recover 15%/20%/25%/30% of damage dealt during it's duration, be it attack damage or spell damage).

This also falls under this category because it works almost like Feast, the bonus damage dealt by Feast will also count towards the Open Wounds recovery amount, as will all the skills that provide bonus damage, incuiding Critical Strikes or Bashes.