Life Leach is a skill that can be used by human characters. Once trained in this skill, it is always in effect.
Skill Text: "With Life Leech, you don’t just wound your enemy as you hit him, but also gradually drain his life energy from his body and perchance add it to your own with each hit you score."
Note: There are numerous conditions and that given the Life Leech skill and it's stacking with the Life Leech enchantment. Please see Further Clarification bellow:
Leech Amount (%)
Chance to Leech (%)
Further Life Leech Clarification:
At skill level 13, there is a 34% chance that a hit for 100 physical melee damage will heal the player for 32 life. This is how the game does the math.
The Life Leech skill will attempt to life leach on normal melee hits and melee skills; the Life Leech enchantment only works with normal melee hits.
The Life Leech skill will not work with magic damage, this includes magic damage on weapons. The blue numbers in parentheses on the character sheet will not apply to the life leach amount.
The Life Leech skill does not work with ranged attacks.
The Life Leech skill can effect multiple enemies in a single hit but it attempts to leech each enemy separately. At level 13 there is an ~1/3 chance to leech from one enemy with a single attack, ~1/9 to leech from two (1/3 * 1/3 = 1/9), a ~1/27 to leech from three enemies, etc.
Some monsters seem to have life leech resistance, in a test of 200 attacks the Life Leech functioned far less than 34% of the time.
The stacking mechanics for the Life Leech skill and the Life Leech enchantment are not clear but in a test of 200 hits the amount of damage leeched never exceeded 32%; the leech amounts from the skill and then enchantment do not stack. A few hits normal melee hits however, did show two different leech numbers; it seems the enchantment and the skill can both effect the same enemy.
These observations were based on the damage numbers observed per hit, no parsing software was used. These number are accurate but are very likely not perfect.
Ultimately how effective is life leech? It was observed that character fighting the boss of the game at an even level, with full dual wield expertise, dual wielding two life leach enchanted weapons and with the level 13 life leech skill will be easily able to win the fight by spamming their primary attack.