*Lethality*redirects here. For the 2013 Mastery, see Lethality.

**Armor penetration** is a champion statistic that determines the amount of a target's armor that will be ignored when the user deals physical damage. **Percentage armor penetration** and **Lethality** have no effect if the target's armor is less than or equal to 0.

**Armor reduction** is an effect that reduces the target's armor for a period of time, by an amount or percentage. **Flat** armor reduction can reduce armor values below 0, while **percentage** armor reduction cannot.

It is important to note that **penetration** *treats* the target's resistances as being multiplied by a percentage or reduced by a flat amount, in contrast to **reduction** which applies to the target's resistances as a whole.

All champions have 0 base armor penetration and lethality, but they can be increased by items, runes, and with certain champions' passive ability effects.

Starting in V6.22, **lethality** replaced **flat armor penetration** as a statistic, and offered 40.33% − 100% (based on target's level) of the value as penetration.^{[1]} In V7.14, it was changed to scale with the user's level instead of the target's level, offering 62.22% − 100% (based on level) of the value as penetration. In V14.1 **lethality** was changed back to no longer scale by level; it grants the full amount of **flat armor penetration** at all levels, but keeps the name to differentiate it from *percent armor penetration* and emphasize its relative effectiveness against low-armor enemies rather than high-armor enemies.^{[2]} In V14.9, **lethality** was updated to be handled as an innate statistic rather than a scripted one.

## Order of calculations[]

Armor penetration and armor reduction are considered in the following order:^{[3]}

- Armor reduction, flat
- Armor reduction, percentage
- Armor penetration, percentage
- Armor penetration, flat (Lethality)

**Base** armor and **bonus** armor are calculated separately.

## Flat armor reduction[]

The target's armor is reduced by an amount. Flat armor reduction stacks additively and is distributed proportionally between base armor and bonus armor.

*Example: 15 armor reduction against a 20 base armor and 40 bonus armor target will reduce base armor by 5 and bonus armor by 10, so the target will be reduced to 45 armor ((20 − 5)*+*(40 − 10) = 45*)*.*

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). Applies to both base and bonus armor. Percentage armor reduction stacks multiplicatively and is ignored if the target's armor is 0 or less.

*Example: 30% armor reduction multiplies the target's armor to 70%, so a target with 20 base armor and 40 bonus armor will be reduced to 42 armor ((20 × 0.7*) + (*40 × 0.7*)*= 42).*

Percentage armor reduction reduces more armor 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.

With 40% armor reduction, the physical damage dealt to a target with 50 armor is only increased by around 15%, whereas the physical damage dealt to a target with 200 armor is increased by around 36%.

If one wanted to calculate the total armor reduction after two consecutive percent armor reductions, the following formula may be useful:

Each *r* is the individual percent armor reductions. For example, the calculation of two armor reductions, 20% and 30%, would yield the following:

## 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 and is ignored if the target's armor is 0 or less.

*Example: 30% armor penetration causes the target to take damage as if its armor was multiplied by 70%, so a target with*20 base armor and 40 bonus armor will be treated as though it had 42 for purposes of damage*(the target's actual armor value will not change, however)*(*(20 × 0.7*)*+*(40 × 0.7) = 42).

Because the target's actual armor value does not change, anything else depending on that value also doesn't change.

Percentage armor penetration reduces more armor 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.

### Percentage bonus armor penetration[]

Percentage armor penetration that applies only to **bonus** armor.

*Example: 30% bonus armor penetration multiplies the target's bonus armor to 70% without affecting base armor, so a target with 20 base armor and 40 bonus armor*will be treated as though it had 48 for purposes of damage calculation (the target's actual armor value will not change, however).*(20*+ (*40 × 0.7*)*= 48).*- If the unit has multiple sources of percentage bonus penetration, they stack multiplicatively:
*Example: 10% armor penetration and 30% bonus armor penetration*.*(20 × 0.9))*+ (*40 × 0.7 × 0.9)*)*= 43.2).*

Because the target's actual armor value does not change, anything else depending on that value also doesn't change.

Percentage bonus armor penetration reduces more armor on targets with higher **bonus** armor, but will not have an effect against base armor. For instance, with 40% **bonus** armor penetration, a target with 200 **bonus** armor will be considered as having 80 less while a target with only 50 **bonus** armor will be considered as having 20 less. In contrast, a target with any amount of base armor and no **bonus** armor will be considered as having the same value.

## Lethality[]

**Lethality** is the statistic that represents and grants flat armor penetration.

The target's armor is treated as being reduced by an amount for the purposes of damage calculation, but cannot be reduced below 0. Flat armor penetration stacks additively.

*Example: 20 lethality on a user will cause a 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.

**Lethality**has a gold value of 30 per point, for more details see this page.

## Examples[]

Given 10 flat armor penetration and 45% bonus armor penetration, and the target is affected by 30 flat armor reduction and 30% armor reduction;

- Target A has 300 armor (100 base and 200 bonus armor).
- The 300 is reduced to 270 (90 base and 180 bonus armor) by the 30 armor reduction.
- The 270 is reduced to 189 (63 base and 126 bonus armor) by the 30% armor reduction.
- The 189 is considered to be 132.3 (63 base and 69.3 bonus armor) by the 45% bonus armor penetration.
- The 132.3 is considered to be 122.3 by the 10 armor penetration.
- Target A takes damage as if it has 122.3 armor.

- Target B has 18 armor.
- The 18 is reduced to −12 by the 30 armor reduction.
- The −12 is not affected by any further calculations because it is less than 0.
- Target B takes damage as if it has −12 armor.

## Lethality as scaling[]

The following have their stats improved based on the amount of lethality acquired:

### Champion abilities[]

- , , , and

### Items[]

## Increasing lethality[]

### Champion abilities[]

### Items[]

This table is automatically generated based on the data from Module:ItemData/data.

#### Item passives[]

## Increasing percent armor penetration[]

### Champion abilities[]

### Items[]

This table is automatically generated based on the data from Module:ItemData/data.

#### Item passives[]

## Reducing armor[]

### Champion abilities[]

- Percentage Reduction

- (Empowered)

- Flat Reduction

### Items[]

- Percentage Reduction

### Monsters[]

- Flat Reduction

## Notes[]

- Armor penetration will apply to any and all sources of physical damage.
- It will apply to the damage dealt to almost every type of unit, including turrets but not other structures (Inhibitors are the only building with armor).

- Armor reduction will affect the physical damage from any unit source.
- Percentage penetration is applied before flat penetration.
- Turrets and have 30% armor penetration.

## Trivia[]

### Highest Lethality[]

**Last updated:** January 20, 2024, patch V14.10

The highest amount of *lethality* any champion can obtain is **127**.

**Items:**- This item grants an additional 10 lethality at the highest level with its passive effect, Preparation.

- 27
- - 18
- - 18
- - 18
- - 18
- - 18

**Relevant mathematics:****Items**= + 10 + + + + + =**127 lethality**- This is further increased to
**160**lethality with when is included in the equation (*127*+*33*=**160**), which grants 33 lethality when lethality is fully leveled. This is the highest amount of lethality in the game that only can obtain.

- This is further increased to

### Highest Armor Penetration (%)[]

The highest amount of percentage armor penetration any champion can obtain is **40%** with .

The highest amount of percentage armor penetration obtainable in the game is **64%** with when he has and his is at rank 5.

**Relevant mathematics:***(1 -*× (1 - )0.4)*=*0.36*1 - 0.36*=*0.64*× 100 =**64%**armor penetration