How Does Lethality Work in League of Legends?

Lethality is one of the key mechanics for assassins and AD-based champions in League of Legends, allowing them to bypass enemy armor and deal more damage. But how exactly does it work? Let’s break it down.

Source: LoL FANDOM

Lethality vs. Armor Penetration – A Key Difference

Back in the day, Lethality didn’t exist. Instead, we had Flat Armor Penetration, which was much simpler. If you had 20 Armor Penetration, you would ignore 20 armor from your target—straightforward and effective.

However, Riot Games wanted a system that scaled better throughout the game, so they introduced Lethality, a stat that gradually increases in effectiveness as you level up.

How Lethality is Calculated

Lethality works using the following formula

This means that if you buy an item with 18 Lethality, you won’t ignore 18 armor immediately. Instead, its effectiveness increases as you level up, reaching the full 18 armor penetration only when you hit level 18.

Example Calculation

Imagine you’re playing Qiyana at level 14, and you have two Lethality items that give you a total of 41 Lethality.

Using the formula:

Yes, League of Legends uses decimal values for calculations, so even partial armor reduction applies.

Lethality in Real Gameplay Scenarios

Here’s a quick reference for how much armor you ignore at different levels with varying Lethality values:

Total Lethality	Level 6 Armor Penetration	Level 11 Armor Penetration	Level 18 Armor Penetration
18	6	11	18
30	10	18	30
50	16	27	50

Important Limitations

Lethality cannot reduce armor below 0. If a champion has 60 armor, and you have 70 armor penetration, you will only ignore 60 armor, not more.
Lethality is different from Percentage Armor Penetration and Armor Reduction, which apply differently and can stack multiplicatively.

What’s Next?

Lethality is a crucial mechanic for assassins and aggressive AD champions, helping them burst down squishy targets. However, it functions differently from Percentage Armor Penetration and Armor Reduction, which I’ll be covering in my next guide!

Make sure to follow and stay tuned for the next breakdown on LoLNOW.gg!

Frequently Asked Questions about Lethality in League of Legends

What is Lethality in League of Legends?

Lethality is a stat that grants flat armor penetration, scaling with your champion’s level. Unlike the old Armor Penetration stat, Lethality becomes more effective as you level up, reaching its full value at level 18.

How is Lethality calculated?

Lethality is calculated using the formula: Armor Penetration = Lethality × (Champion Level / 18). This means that the effectiveness of Lethality increases as you gain levels.

Does Lethality reduce armor below zero?

No, Lethality cannot reduce a champion’s armor below zero. If you have more Armor Penetration than the target’s total armor, you will only ignore up to their current armor value.

Is Lethality better than Percentage Armor Penetration?

Lethality is more effective against squishy targets with low armor, while Percentage Armor Penetration is better against tanks and champions with high armor values.

Which champions benefit the most from Lethality?

Assassins and AD-based burst champions like Qiyana, Zed, Talon, and Miss Fortune benefit the most from Lethality since it helps them deal high burst damage against low-armor targets.

Does Lethality stack with other forms of Armor Penetration?

Yes, Lethality stacks additively with other Lethality sources, but it is calculated separately from Percentage Armor Penetration and Armor Reduction effects.