目录
1 Order of calculations
2 Flat armor reduction
3 Percentage armor reduction
4 Flat armor penetration
5 Percentage armor penetration
6 Examples
7 Increasing armor penetration
7.1 Items
7.2 Champion abilities
7.3 Masteries
7.4 Runes
7.5 Neutral buffs
8 Reducing armor
8.1 Items
8.2 Champion abilities
9 Notes
10 See also
11 References
Armor penetration is a champion statistic that allows the champion to ignore some or all of a target's armor. All champions have 0 base armor penetration but can increase it with items, runes, masteries and some champion abilities. This cannot affect enemy armor beyond 0 to deal bonus damage.
Armor reduction is the effect of some items and champion abilities that temporarily reduces the armor of one or more targets. This allows allies to benefit from the reduction of armor. This can reduce armor below 0, resulting in bonus damage (see Armor).
Order of calculations[]
When attacking, armor penetration and armor reduction are considered on the target champion in the following order[1]:
Flat armor reduction
Percentage armor reduction
Flat armor penetration
Percentage armor penetration
Flat armor reduction[]
The target's armor is reduced by an amount. Flat armor reduction stacks additively.
Example: 20 armor reduction reduces the target's armor by 20, so a target with 30 armor will be reduced to 10 armor. (30 − 20 = 10)
Flat armor reduction can reduce a target's armor below zero. For example, if an enemy with 10 armor has their armor reduced by 25, the enemy will have −15 armor.
Percentage armor reduction[]
The target's armor is multiplied by a percentage (100% − the listed reduction). Percentage armor reduction stacks multiplicatively. Percentage armor reduction is ignored if the target's armor is 0 or less.
Example: 20% armor reduction multiplies the target's armor to 80%, so a target with 30 armor will be reduced to 24 armor. (30 × 0.8 = 24)
Percentage armor reduction makes a bigger difference on targets with higher armor. For instance, with 40% armor reduction, a target with 200 armor will lose 80 while a target with only 50 armor will lose 20.
Flat armor penetration[]
The target's armor is treated as being reduced by an amount for purposes of damage calculation, but cannot be reduced below 0. Flat armor penetration stacks additively.
Example: 20 armor penetration causes the target to take damage as if its armor was 20 less, so a target with 30 armor will be treated as though it had 10 for purposes of damage calculation (the target's actual armor value will not change, however).
Because the target's actual armor value does not change, anything else depending on that value also doesn't change (e.g. Rammus' Spiked Shell).
Percentage armor penetration[]
The target's armor is treated as being multiplied by a percentage for purposes of damage calculation (100% − the listed penetration). Percentage armor penetration stacks multiplicatively. Percentage armor penetration is ignored if the target's armor is less than 0.
Example: 20% armor penetration causes the target to take damage as if its armor was multiplied by 80%, so a target with 30 armor will be treated as though it had 24 for purposes of damage calculation (the target's actual armor value will not change, however).
Because the target's actual armor value does not change, anything else depending on that value also doesn't change (e.g. Rammus' Spiked Shell).
Percentage armor penetration makes a bigger difference on targets with higher armor. For instance, with 40% armor penetration, a target with 200 armor will be considered as having 80 less while a target with only 50 armor will be considered as having 20 less.
Examples[]
Given 20 flat armor reduction and 30% armor reduction, and the target is affected by 10 flat armor penetration and 40% armor penetration,
Target A has 80 armor.
The 80 is reduced to 60 by the 20 armor reduction.
The 60 is reduced to 42 by the 30% armor reduction.
The 42 is considered to be 32 by your 10 armor penetration.
The 32 is considered to be 19.2 by your 40% armor penetration.
Target A takes damage as if it has 19.2 armor.
Target B has 18 armor.
The 18 is reduced to −2 by your 20 armor reduction.
The −2 is not affected by any further calculations because it is less than 0.
Target B takes damage as if it has −2 armor.
Increasing armor penetration[]
Items[]
Last Whisper: Unique passive: +40% armor penetration. +40 attack damage. 2290 gold.
The Brutalizer: Unique passive: +15 armor penetration, +25 attack damage. Unique passive: +10% cooldown reduction. 1337 gold.
Youmuu's Ghostblade: Unique passive: +20 armor penetration. +30 attack damage; +15% critical chance; +15% cooldown reduction. Unique active: You gain +20% movement speed and +50% attack speed for 4 seconds. Attacking enemy units with melee attacks increases the duration by 2 to a maximum of 8 extra seconds. 60 second cooldown. 2687 gold.
Lord Van Damm's Pillager: Unique passive: +25 armor penetration. +40 attack damage; +350 health. Unique passive: +10% cooldown reduction; +10% spell vamp. 2962 gold
Champion abilities[]
Note: Only the armor penetration effect of these abilities is shown here, to read more information on each of these abilities, follow the link on each of them.
Olaf's Ragnarok passive grants him 10 / 20 / 30 armor penetration.
Darius' Apprehend passively grants him 5% / 10% / 15% / 20% / 25% armor penetration.
Masteries[]
File:Weapon Expertise.png Weapon Expertise: Gives 10% armor penetration.
File:Sunder.png Sunder: Gives 2 / 4 / 6 armor penetration.
Runes[]
Desolation runes provide flat armor penetration. These are commonly purchased because, especially along with armor penetration quintessences and against an enemy with low starting armor, armor can be brought very low, if not to zero, from the very beginning of the game and armor penetration is hard to acquire otherwise from items or abilities. Destruction runes provide flat armor penetration and magic penetration.
Neutral buffs[]
Crystal Scar's Aura grants every champion 12% armor penetration while playing on the Dominion game mode.
Reducing armor[]
Items[]
The Black Cleaver: Unique passive: Physical attacks reduce your target's armor by 15. This debuff stacks up to 3 times and lasts for 5 seconds. +55 attack damage, +30% attack speed. 2865 gold.
Champion abilities[]
Note: Only the armor reduction effect of these abilities is shown here, to read more information on each of these abilities, follow the link on each of them.
Percentage Reduction:
Jarvan IV's Dragon Strike reduces the armor of all enemies hit by 10% / 14% / 18% / 22% / 26% for 3 seconds.
Jayce's Transform: Mercury Cannon reduces the armor and magic resistance of the enemy hit by his first attack after cast, by 10% / 15% / 20% / 25% for 5 seconds
Kayle's Holy Fervor reduces the armor and magic resistance of enemies hit by her autoattacks by 3% for 5 seconds. This debuff stacks up to 5 times.
Nidalee's Bushwhack reduces the armor and magic resistance of enemies that step on the trap by 20% / 25% / 30% / 35% / 40% for 12 seconds.
Renekton's Slice and Dice, when empowered by having more than 50 Fury, Dice will reduce the armor of all enemies hit by 15% / 20% / 25% / 30% / 35% for 4 seconds.
Shyvana's Flame Breath reduces the armor of all targets hit by 15% for 4 seconds.
Trundle's Agony targets an enemy to steal their armor and magic resistance by 15% / 20% / 25%, this amount is doubled over the next 6 seconds.
Urgot's Noxian Corrosive Charge reduced the armor of all enemies hit by 12% / 14% / 16% / 18% / 20% for 5 seconds.
Wukong's Crushing Blow reduces the armor of the target hit by 30% for 3 seconds.
Xin Zhao's Challenge reduces the armor of the target by 15% for 3 seconds with his basic attacks and Audacious Charge. Only one target can be challenged at a given time.
Flat Reduction:
Corki's Gatling Gun fires automatically every half second, reducing enemies armor with each hit by 2 / 4 / 6 / 8 / 10 for 2 seconds.
Heimerdinger's H-28G Evolution Turret, while in ranks 2, 3, 4 and 5, the turrets' attacks reduce armor and magic resist by 1 per hit stacking up to 50 times.
Kog'Maw's Caustic Spittle reduces the target's armor and magic resistance by 5 / 10 / 15 / 20 / 25 for 4 seconds.
Nasus' Spirit Fire reduces the armor of all enemies in the area by 20 / 25 / 30 / 35 / 40 for the time they are on it plus 1 second.
Rammus' Puncturing Taunt reduces the target's armor by 10 / 15 / 20 / 25 / 30 for 1 / 1.5 / 2 / 2.5 / 3 seconds.
Taric's Shatter reduces the armor of all enemies hit by its activation damage by 10 / 15 / 20 / 25 / 30 for 4 seconds.
Notes[]
Armor penetration is a very valuable stat for physical damage dealing champions. There are few sources for it, so Desolation marks and quintessences are very popular runes.
Armor penetration benefits all sources of physical damage including all champion abilities that deal physical damage.
For example, Xin Zhao's Crescent Sweep will benefit from armor penetration as it deals physical damage, however his Audacious Charge will not benefit from armor penetration as it deals magical damage.
The on-hit effect on items like Tiamat.
See also[]
Magic penetration
Armor
Champion statistic
References[]
↑ http://www.youtube.com/watch?v=OiXRjVxu5Mk at Youtube.com
Champion statistics
Offensive
Attack damage
Attack speed
Critical strike
Life steal
Armor penetration
Movement speed
Defensive
Health
Health regeneration
Armor
Magic resistance
Tenacity
Magical
Mana
Mana regeneration
Ability power
Cooldown reduction
Magic penetration
Spell vamp