What Does Lethality Do in LoL? | Lethality Explained

Lethality is a stat that grants flat armor penetration, meaning it reduces a flat amount of your target’s armor before damage is calculated. It scales with the enemy’s level, so the higher their level, the more armor you'll ignore. This makes lethality most effective in the early to mid game, when armor values are still low and percentage armor penetration isn’t yet necessary.

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The Lethality Formula

The formula looks like this:

Flat Armor Penetration = Lethality × (0.6 + 0.4 × (Target Level ÷ 18))

At level 18, you get the full value of your lethality as flat armor penetration. At lower levels, you get less. This scaling is automatic, and you don’t need to do anything for it to apply.

Note that flat penetration is calculated after effects like armor reduction or percentage reduction modifiers have been applied. This matters when facing targets with already reduced armor values from things like Black Cleaver or certain champions' passive effects.

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Who Benefits Most from Lethality?

Lethality is best for attack damage champions who rely on burst damage and have high bonus AD scaling, usually assassins and ranged poke champions. These include champions like:

• Zed

• Talon

• Miss Fortune

• Kha’Zix

• Varus (Lethality build)

• Naafiri

Because lethality grants flat penetration, it’s most effective against enemies with low armor, usually mages, ADCs, and supports. It falls off against tanks or bruisers who stack more armor early. Against such targets, percentage armor penetration or percentage bonus penetration will do a better job of cutting through defenses.

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Lethality vs. Armor Penetration

Lethality and armor penetration both help physical damage get through armor, but they work differently, and they’re not interchangeable. They can, however, be stacked together for optimal value, especially against mixed-composition teams.

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Flat vs. Percentage Penetration

• Lethality grants flat armor penetration that scales with the enemy’s level. It’s best against low-armor targets.

• Percentage armor penetration (sometimes listed as percent armor penetration or percentage bonus armor penetration) removes a flat percentage of the enemy armor, whether base or bonus depending on the specific modifier.

Due to how the math around damage mitigation works, you'll get more value from flat armor reduction when enemies have low armor, and more from percentage penetration when they stack defenses.

Example:

• If a target has 60 total armor, and you have 18 lethality, you can reduce ~18 of it—nearly a third.

• If they have 300 armor, reducing 18 barely matters. Percentage armor penetration or percentage bonus penetration is needed to make a dent in the target’s bonus armor.

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Armor Penetration Variants

There are three major mechanics that reduce armor:

1. Flat armor reduction: Directly lowers the target's armor number. Applies to everyone hitting that target.
   • Example: Wukong’s Crushing Blow, or Black Cleaver's passive.

2. Percentage armor penetration: Reduces a portion of all of the target’s armor (base + bonus).
   • Example: Lord Dominik’s Regards.

3. Percentage bonus armor penetration: Affects only the bonus armor (from items, buffs).
   • Example: Black Cleaver, or some certain champions' passive effects like Kha'Zix’s evolved Q.

All of these effects stack multiplicatively, not additively. So two 20% reductions don’t equal 40%, but rather apply one after the other—resulting in 36% reduction from the original value.

This is especially important when chaining consecutive percent armor reductions. For example, hitting a jungle monster with multiple armor-reducing abilities will yield diminishing returns, but will still result in armor reduced enough to help your teammates. For monsters, there's often a percentage reduction monsters cap to prevent excessive abuse.

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When to Build What

• Use lethality when you're snowballing, facing squishy enemies, or building for burst damage.

• Use percentage armor penetration or percentage bonus armor penetration against tanks and fighters who stack bonus armor.

• In some builds, you'll want both. For longer games, many lethality users transition into items that offer percentage penetration or flat reduction items for sustained pressure.

  

Assassins can consider pairing lethality with Serylda’s Grudge, Black Cleaver, or even LDR to combine burst with durability-shredding.

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Lethality in Early, Mid, and Late Game

Lethality’s effectiveness depends heavily on timing and scaling. It’s all about knowing how much enemy armor is on the field and how well your items interact with it.

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Early Game: Strongest Impact

At this stage, most targets have low armor, and no defensive items. Lethality directly shaves off a large portion of their target’s armor, especially with an early Serrated Dirk.

Champions like Talon or Zed can make use of early lethality to force fights before opponents can stack defenses. This is also when basic attack enhancement from bonus AD becomes especially punishing.

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Mid Game: Conditional Value

From levels 8 to 11, many champions start accumulating armor, either passively or through items. This is the pivot point where percentage armor penetration reduces become more valuable.

If you're still one-shotting backline squishies, lethality works. But if fights drag, attack speed, percentage reduction, and damage over time become more relevant.

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Late Game: Sharp Drop-Off

By the late game, even ADCs commonly have 100+ armor. That’s well past the threshold where flat armor penetration is efficient.

Unless you’re playing champions that scale off lethality directly (e.g. Pyke), or ones with extreme mobility/utility scaling (e.g. Kha’Zix), you’ll want to swap at least one item for percentage armor penetration or lethality items that include percentage effects.

This is especially true against tanks where you must reduce armor values via combined flat and percentage penetration, or exploit magic resistance reduced indicator effects in mixed-damage comps.

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Best Lethality Items

Youmuu’s Ghostblade

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Voltaic Cyclosword

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Opportunity

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Umbral Glaive

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FAQ – Lethality Basics

What does lethality do in LoL?

Lethality grants flat armor penetration, scaling with target level. It reduces the target’s armor directly, improving physical damage effectiveness, especially against those with little or no armor.

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Is lethality good for all AD champions?

No. It’s best for burst AD assassins or lethality users with high ratios. Bruisers, tanks, or ADCs focused on attack speed and critical strike chance benefit more from other damage types.

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Does lethality scale late game?

Lethality does no longer scale well into the late game due to its flat nature. As target’s bonus armor grows, flat effects like lethality lose value compared to percentage armor penetration or individual percent armor reductions.

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Does lethality work on towers?

No, it affects monsters but not other structures. It also doesn't help against structures like turrets, inhibitors, or nexus. Still, it works on jungle monsters, most of whom have very low armor and can be burst quickly.

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Conclusion

Lethality is a powerful but timing-sensitive stat for attack damage champions who want to break through armor early.

• It provides flat armor penetration that scales with enemy level.

• It shines in the early game but is outclassed by percentage armor penetration obtainable later.

• Armor reduction, whether flat or percentage, can further enhance your damage when combined properly.

Understand when to stack lethality items versus when to shift to percentage armor reduction reduces and consecutive percent armor reductions. If unsure, test in Practice Tool against dummies with different setups. The more you understand how to reduce armor values, the more consistent your damage will be, no matter who you’re facing.