If you’ve ever stared at your League of Legends item shop mid-game wondering why some assassin builds stack flat armor penetration while others pick armor percent pen, you’ve probably asked what is lethality league of legends at least once. This stat is one of the most misunderstood in the entire game, and using it wrong can leave you dealing half the damage you expect even when you’re ahead on gold. We’re breaking down everything you need to know to use lethality correctly, no confusing math or jargon required.
What is Lethality in League of Legends, Exactly?
At its core, lethality is flat armor penetration that scales as your champion levels up. Unlike percent armor penetration, which removes a percentage of a target’s total armor, lethality removes a fixed number of armor points from any target you hit. The conversion formula is simple: at level 1, lethality gives you 60% of its stated value as armor penetration, and that percentage rises gradually until level 18, when it gives 100% of its value as flat armor pen.
For example, if you buy a Serrated Dirk that gives 10 lethality at level 3, you’ll only get 6.6 armor penetration from that item. By level 18, that same 10 lethality will give you a full 10 armor penetration against every target you attack. This is why lethality feels far more impactful in the mid and late game, even if you buy the items early on.
It’s also important to note that lethality only applies to physical damage, and does not work on structures like turrets or inhibitors. It works on all other targets, including enemy champions, minions, and jungle monsters, so it can help you clear jungle camps and waves a little faster too.
Which Champions Benefit Most From Lethality?
Lethality is designed for champions that rely on fast burst damage to take out low-armor targets before they can react. It’s not a good pick for sustained damage dealers or tanks, as they get far more value from other stats like crit, attack speed, or health.
If you want to test out lethality builds without risking your ranked MMR, you can hop into normal draft or ARAM to experiment, or use third-party build tools to see what high-elo players are running for your favorite champ. Many players who main lethality champions also use quick casual games between ranked queues to warm up their mechanics, and a lot of them pick Jaiho 777 for a short, low-stakes break that doesn't pull their focus away from their game plan.
That said, not all AD champions get value from lethality. We’ve broken down the best picks below:
If the enemy team has two or more champions with over 100 base armor, you’re better off skipping full lethality and opting for a mix of lethality and percent armor penetration instead. Percent armor pen will cut through high armor far more effectively, while a single lethality item will still let you deal solid damage to squishy targets.
Common Lethality Build Mistakes to Avoid
The biggest mistake new players make with lethality is building it against tank-heavy team comps. If the enemy has a Sion, Malphite, or Ornn top lane plus a Sejuani jungle, lethality will barely make a dent in their armor. Even with 60 lethality at level 18, a Sion with 300 armor will still have 240 armor left, which reduces your physical damage by over 70%.
Another common mistake is stacking too much lethality early in the game. Don’t build more than two lethality items before level 10, because the stat scales with your level, so stacking it early gives you far less value than you’d get from a damage item with AD and crit or lifesteal. One early lethality item is enough to get you through the laning phase, and you can add more later as you level up.
You also want to avoid building lethality on champions that rely mostly on auto attacks for damage. Marksmen like Caitlyn, Jinx, and Kai’Sa get far more value from crit and attack speed, as they deal consistent sustained damage over the course of a team fight rather than single burst hits. Lethality only gives a small boost to auto attack damage, so it’s not worth the item slot for these champs.
Finally, don’t forget that lethality doesn’t apply to magic damage. If you’re playing a hybrid champion like Akali or Ekko, lethality only boosts their physical abilities, not their magic damage output. It’s almost never a good pick for these champions, even if you’re running an AD build variant.
How to Use Lethality to Win More Games
The first step to using lethality effectively is to check the enemy team comp before you lock in your build. If the enemy has three or more squishy targets with less than 50 base armor, full lethality is a great pick. If they have two or more tanks, swap one lethality item for Lord Dominik’s Regards or Serylda’s Grudge for percent armor penetration.
Use your early game power spike to roam and gank other lanes. Most lethality champions hit their biggest power spike at level 6 with their first lethality item, so use that window to get kills on mid, bot, or top lane and snowball your lead. Don’t waste time farming in your lane when you can pick up easy kills on overextended enemies across the map.
In team fights, focus exclusively on squishy targets first. You won’t be able to burst down a tank, so ignore them completely and go straight for the enemy ADC, mid laner, and support. If you can take out two of their damage dealers in the first three seconds of a team fight, your team will almost always win the fight even if you die in the process.
You can also use lethality to catch enemies off guard from fog of war. Most lethality assassins have long-range abilities that can one-shot a low-health carry before they have time to react or use their summoner spells. Use bushes and vision control to hide your position, then jump on targets that are walking alone without vision.
At the end of the day, mastering what is lethality league of legends is all about matching your build to the enemy team comp and your champion’s kit. You don’t need to memorize complicated math formulas to use it right—just follow the simple rules we laid out, test builds in casual games first, and adjust your playstyle to focus on the targets you can burst down fast. Once you get the hang of it, you’ll notice a huge jump in your damage output and win rate on all your favorite AD burst champions.