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.[1][2]
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.[3]
The total amount of life or mana leeched without Vaal Pact can be described as
- HP(t) = r * t
where r is the leech recovery rate and t is the time. The leech recovery rate, r, varies depending on how many enemies have been hit and how many times the enemies have been hit. [4]
Recovery rate
| Symbol | Value | Description |
|---|---|---|
| q | 2 % 2 % |
Base Life Leech Rate Base Mana Leech Rate |
| qmax | Expression error: Unrecognized punctuation character "[".% Expression error: Unrecognized punctuation character "[".% |
Base Maximum Life Leech Rate Base Maximum Mana Leech Rate |
The leech recovery rate r is given by
- r = p * n * q * (1 + m)
where p is the character's maximum life (for life leech) or mana (for mana leech), n is the number of active leech instances, q is the Base Leech Rate and m is the sum of all the #% increased (or reduced) Life/Mana Leeched per second modifiers.
There is a upper limit of the leech recovery rate which is defined as
- rmax = p * (qmax + mmax)
where qmax is the Base Maximum Leech Rate and mmax is the sum of all the #% of maximum Life/Mana per second to maximum Life/Mana Leech rate modifiers.
If r > rmax those values will be substituted with rmax. The total amount of active leech instances allowed, ntot, to not exceed the maximum recovery rate is
- ntot = (qmax + mmax) / (q * (1 + m))
| Derivation of ntot |
|---|
Find the amount of instances that gives the maximum leech recovery rate:
solving for n yields the total amount of active leech instances allowed
|
Leech duration
The leech recovery duration for each instance in seconds is given by [5]
- tdur = d * l / (p * q)
where d is the damage inflicted on the enemy, l is the total amount of leech. The leech duration is independent on other leech instances. [5] 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.
To be able to sustain the maximum recovery rate, rmax, against a single target the total amount of instances allowed needs to be active at all times, ntot. The attack time between each hit, tatt, needs to be
- tatt ≤ tdur / ntot
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, tdur, of the leech effects, meaning that more total life/mana will be gained from each leech instance as a result.[3][5] 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:[3][6]
- The of Smothering modifier for maps slows life and mana leech recovery rate by 50%.
- For life leech by a skill supported by the Module Error: No skills found with q_where = skill.active_skill_name="Life Leech" gem.
- Vorici's master modifier also offers #% increased Life Leeched per second.
Examples
When using skills such as 
Dual Strike linked with Module Error: No skills found with q_where = skill.active_skill_name="Melee Splash" 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 |
|---|
The recovery rate is:
Make sure that the recovery rate doesn't exceed the maximum recovery rate which is
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
which gives the total life leeched
|
| 5 enemies hit at once |
|---|
The recovery rate is:
Make sure that the recovery rate doesn't exceed the maximum recovery rate which is
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
which gives the total life leeched
|
| 11 enemies hit at once |
|---|
The recovery rate is:
Make sure that the recovery rate doesn't exceed the maximum recovery rate which is
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
which gives the total life leeched
|
| 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 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
- Module Error: No skills found with q_where = skill.active_skill_name="Life Leech" and Module Error: No skills found with q_where = skill.active_skill_name="Mana Leech" has the mod #% of Damage Leeched as Life/Mana implying it works for all types of skills that hits a target.
- Module Error: Too many skills found with q_where = skill.active_skill_name="Warlord's Mark". Please choose only one of the following ids:
WarlordsMark - Base duration is (6-9.8) seconds, Hits against Cursed Enemies have (40-59)% chance to double Stun Duration, Cursed Enemies grant 20 Rage Regenerated over 1 second when Stunned, Cursed enemies grant 2% Life Leech when Hit by Attacks, Cursed enemies grant 2% Mana Leech when Hit by Attacks, Cursed enemies have a 100% chance to grant an Endurance Charge when slain (page)
WarlordsMarkTriggered - Base duration is (7.4-8.2) seconds, Trigger this Skill when you Hit a Rare or Unique Enemy (page) 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.
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
Miscellaneous
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. 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
Immunity to leech
A player can become immune to being life leeched from by enemies through allocating the Bloodless notable passive skill.
Template:Passive table
Immunity can also be achieved by equipping certain unique items.
Lua error in Module:Cargo at line 896: bad argument #1 to 'gsub' (string expected, got nil).
Cannot Leech
Certain unique items prevent the user from leeching life and/or mana.
Lua error in Module:Cargo at line 896: bad argument #1 to 'gsub' (string expected, got nil).
References
- ↑ GGG_Mark (August 6, 2013). "Evasion and Damage Reflection questions". Path of Exile forum. Retrieved November 17, 2015.
- ↑ GGG_Mark (July 1, 2013). "Explosive Arrow". Path of Exile forum. Retrieved November 17, 2015.
- ↑ 3.0 3.1 3.2 3.3 GGG_Neon (May 18, 2015). "Upcoming changes to Leech Thread". Path of Exile Forum. Retrieved July 20, 2015.
- ↑ GGG_Mark (June 20, 2015). "Vitality Void: Leech Cluster Thread". Path of Exile subreddit. Retrieved July 20, 2015.
- ↑ 5.0 5.1 5.2 GGG_Mark (October 1, 2015). "Life leech (wiki)". Path of Exile forum. Retrieved October 12, 2015.
- ↑ Mark_GGG (March 4, 2014). "Leech: GGG clarify please!". Official Path of Exile Forums. Retrieved March 6, 2014.