Leech

"Life Leech" redirects here. For the support gem, see Life Leech (support gem). For the passive skill, see Life Leech (passive skill).

"Mana Leech" redirects here. For the support gem, see Mana Leech (support gem).

Leech recovers an amount of life, mana or energy shield over time, relative to the damage inflicted on an enemy. Leech cares about the damage taken by the enemy, not the amount of life removed.

Mechanics

In The Awakening expansion the leech mechanics were changed with the goal to make it harder to leech against a single enemy. Earlier the leech recovered at a constant rate, this method do not take into account how many enemies that were hit by the skill. The leech mechanic was therefore changed so that a new leech instance was created per hit. These instances can stack meaning a single hit against multiple targets will grant multiple instances, as will multiple hits against a single target.

A Leech instance is calculated by taking a percent of the damage done in each hit according to the #% Damage Leeched as Life (or Mana) stat then healing the character up by that amount, the speed in which a instance of leech heals character is limited by the leech recovery rate, the default leech recovery rate is 2% of the character's max health per second, which can be increased by #% increased (or reduced) Life/Mana Leeched per second modifiers. There is a maximum amount of leech recovery rate per second which is by default 20% of maximum health, this can be increased by #% of maximum Life/Mana per second to maximum Life/Mana Leech rate modifiers.

Each hit against each target creates a new instance of leech which will all heal the character simultaneously until the maximum leech recovery rate per second is reached.

Recovery rate

The total leech recovery rate (accounting for all instances of leech) is given by

total leech recovery rate = max life * instances of leech * 0.02 * (1 + increased leech per second)

where max life can also be the character's maximum mana for mana leech. Increased leech per second is the sum of all the #% increased (or reduced) Life/Mana Leeched per second modifiers.

There is an upper limit of the leech recovery rate which is defined as 20% of the character's maximum health. This maximum is increased by any #% of maximum Life/Mana per second to maximum Life/Mana Leech rate modifiers.

The total amount of active leech instances allowed that will not exceed the maximum recovery rate is

max instances = (0.2 + increased max leech rate) / (0.02 * (1 + increased leech per second))

Derivation of max instances

Find the amount of instances that gives the maximum leech recovery rate: max recovery rate = recovery rate max life * instances * 0.02 * (1 + increased leech per second) = max instances * (0.2 + increased max leech rate) setting max instances to instances and solving yields the total amount of active leech instances allowed max instances = instances = (0.2 + increased max leech rate) / (0.02 * (1 + increased leech per second))

Leech duration

The leech recovery duration is how long in seconds a leech instance has to last to recover the entirely of its life pool. It can be found by dividing the percent damage inflicted that is leeched by the leech recovery rate.

duration = damage inflicted * % attack damage leeched / (max health * 0.02 * (1 + increased leech per second))

Note that the leeched damage is always rounded down to nearest integer, which can be noticeable for skills that do low amounts of damage quickly.

Modifiers

Modifiers that alters the leech recovery rate increases the value of Life/Mana you're gaining per second for each leech effect. However, it does not affect the duration, t_dur, of the leech effects, meaning that more total life/mana will be gained from each leech instance as a result. This also implies that by increasing the Life/Mana Leeched per seconds gives a larger total of life leeched compared to Vaal Pact.

There are only a couple of ways for these factors to be altered, besides the passive tree:

• The of Smothering modifier for maps slows life and mana leech recovery rate by 50%.
• For life leech by a skill supported by the gem.
• Vorici's master modifier also offers #% increased Life Leeched per second.

Examples

When using skills such as linked with several enemies can be hit at once. The leech rate will vary considerably depending on how many enemies are hit. The character used in the following examples have the following stats:

p = 5000 maximum life.

d = 1000 damage taken by the enemy.

l = 1 % life leech.

1 enemy hit

n = 1 leech instance/enemy. m = 0% increased Life Leeched per second. mmax = 0% of maximum Life per second to maximum Life Leech rate. The recovery rate is: r = n * p * q * (1 + m) = 1 * 5000 * 0.02 * (1 + 0) = 100 HP/sec Make sure that the recovery rate doesn't exceed the maximum recovery rate which is rmax = p * (qmax + mmax) = 5000 * (0.2 + 0) = 1000 HP/sec The limit has not been exceeded, meaning that no substitution is necessary. The time it takes to recover the total amount of life leeched is tdur = d * l / (p * q) = 1000 * 0.01 / (5000 * 0.02) = 0.1 seconds which gives the total life leeched HP(tdur) = r * tdur = 100 * 0.1 = 10 Life

5 enemies hit at once

n = 5 leech instances/enemies. m = 0% increased Life Leeched per second. mmax = 0% of maximum Life per second to maximum Life Leech rate. The recovery rate is: r = n * p * q * (1 + m) = 5 * 5000 * 0.02 * (1 + 0) = 500 HP/sec Make sure that the recovery rate doesn't exceed the maximum recovery rate which is rmax = p * (qmax + mmax) = 5000 * (0.2 + 0) = 1000 HP/sec The limit has not been exceeded, meaning that no substitution is necessary. The time it takes to recover the total amount of life leeched is tdur = d * l / (p * q) = 1000 * 0.01 / (5000 * 0.02) = 0.1 seconds which gives the total life leeched HP(tdur) = r * tdur = 500 * 0.1 = 50 Life

11 enemies hit at once

n = 11 leech instances/enemies. m = 0% increased Life Leeched per second. mmax = 0% of maximum Life per second to maximum Life Leech rate. The recovery rate is: r = n * p * q * (1 + m) = 11 * 5000 * 0.02 * (1 + 0) = 1100 HP/sec Make sure that the recovery rate doesn't exceed the maximum recovery rate which is rmax = p * (qmax + mmax) = 5000 * (0.2 + 0) = 1000 HP/sec The limit has been exceeded, therefore the recovery rate needs to be changed to r = 1000 HP/sec. The time it takes to recover the total amount of life leeched is tdur = d * l / (p * q) = 1000 * 0.01 / (5000 * 0.2) = 0.1 seconds which gives the total life leeched HP(tdur) = r * tdur = 1000 * 0.1 = 100 Life

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Marauder dual strike

For example, let's take a marauder with dual strike skill. p= 5577 life total L= 3.2% base phys leech (gear and passives) m= 93% Inc. leech per second Mmax+13% of max life per second to max life leech rate d= 1400-2500 single attack physical damage (I used MINIMUM main hand damage) n= number of enemies (1 for this example) r= recovery rate Rmax= cap for recovery rate Tdur= Leech duration APS= attacks per second (Variables left in for ease of use) Recovery rate r215.27= p5577 * n1 * q0.02 * (1 + m0.93) Recovery rate max cap Rmax 1187.90 = p5577 * (Qmax0.2 + Mmax 0.013) Leech duration MINIMUM Tdur 0.40 = d1400 * L0.032 / (p5577 * 0.02) MAXIMUM Tdur 0.72 = d2500 * L0.032 / (p5577 * 0.02) Total Leech Figures 86.46 leech per hit per per enemy MINIMUM = r215.27 * Tdur0.40 154.4 leech per hit per per enemy MAXIMUM= r215.27 * Tdur0.72 911.33 to 1627.376 leeched per second per enemy= APS10.54 x 86.464 and then x 154.4 for min/max leech 4556.65 to 8136.88 leeched per 5 enemies per second 9113.3 to 16273.76 leeched per 10 enemies per second

Types of Leech

There's several types of leech that specializes on certain types of skills. Some leech types only works for attacks, others only works with elemental damage or all sources of physical damage. If there is specialization it will be defined in the modifier.

Generally the leech modifiers follow this template:

#% of X Y Damage Z Leeched as Life/Mana

Where X can be:

• Physical/Fire/Cold/Lightning/Elemental/Chaos

Y can be:

• Attack/Spell

and Z can be:

• Dealt with {Weapons}

Note that if X, Y or Z are not specified it means that it applies to all those types.

Examples

• and has the mod #% of Damage Leeched as Life/Mana implying it works for all types of skills that hits a target.
• also has the mod #% of Damage Leeched as Life/Mana, granted the enemy already is cursed.
• The notable passive Soul Raker grants the mod #% of Physical Damage Dealt with Claws Leeched as Life specifying it works for only Physical damage dealt by a Claw, this implies that this passive only works for Attacks because Spells are separate from the weapon.
• The notable passive Lust for Carnage grants the mod #% of Physical Attack Damage Leeched as Life specifying it applies to Physical Attacks. All types of weapons can make use of this notable, however not Spells.

Passive skills

There are passive skills that grant passive leech or bonuses to leech.

Attack Damage Leeched as Life

These passive skills that grant passive life leech when dealing any damage with a weapon. Template:Passive table

Physical Attack Damage Leeched as Life

These passive skills that grant passive life leech when dealing physical damage with a weapon. Template:Passive table

Increased Life Leeched per second

These passive skills increase the rate of life gained while leeching. Template:Passive table

Increase to Maximum Life Leech rate

These passive skills increase the maximum life leech rate. Template:Passive table

Minion Life Leech

These passive skills grant life leech for minions. Template:Passive table

Modifiers

These keystone passive change the way Life Leech works, but do not directly enhance Life Leech. These effects do not apply to Mana Leech.

The Vaal Pact Keystone will allow life leech to apply immediately at the cost of losing life regeneration. Ghost Reaver applies life leech to energy shield instead of life. Endless Hunger causes Life Leech effects to not get removed when the user reaches full life. Template:Passive table

Attack Damage Leeched as Mana

These passive skills that grant passive mana leech when dealing any damage with a weapon. Template:Passive table

Physical Attack Damage Leeched as Mana

These passive skills that grant passive mana leech when dealing physical damage with a weapon. Template:Passive table

Increased Mana Leeched per second

These passive skills increase the rate of mana gained while leeching. Template:Passive table

Increase to Maximum Mana Leech rate

These passive skills increase the maximum mana leech rate. Template:Passive table

Non-Attack Damage Leech

These uniques and abilities grant Leech from methods other than damage dealt with attacks or applies to all forms of damage.

Related effects

These effects are associated with Leech:

Items

• The RetchThe Retch
  Rustic SashRequires Level 44(12-24)% increased Global Physical Damage+(60-80) to maximum Life
  +(30-40)% to Cold Resistance
  0.4% of Physical Attack Damage Leeched as Life
  60% increased Flask Effect Duration
  30% reduced Flask Charges gained during any Flask Effect
  200% of Life Leech applies to Enemies as Chaos Damage
  15% increased Movement Speed during any Flask EffectBut the grain grew twisted and the water turned dark
  and those who partook of Mother Gull's gift
  birthed monsters that fed
  on the flesh of one another.

Immunity to leech

A player can become immune to being life leeched from by enemies through allocating the Bloodless notable passive skill.

Immunity can also be achieved by equipping certain unique items.

Cannot Leech

Certain unique items prevent the user from leeching life and/or mana.