How Armor Works in League of Legends

Rifat Mahmood
By Rifat Mahmood
6 Min Read
Image Source: Riot Games

Armor reduces the damage taken from physical damage sources in League of Legends.

League of Legends is a MOBA where you can play a lot of different characters. At the time of writing this article, League currently has 158 champions you can play with. Some champions deal physical damage, while some deal magic damage. There is also another type of damage called true damage.

  • Physical Damage is also known as attack damage. Champions like Jinx, Caitlyn, Zed, Talon, Riven, Fiora, etc., deal physical damage. Buying armor gives you some defense against champions that deal physical damage.
  • Magic Damage on the other hand, is a type of damage that is non-physical and comes from AP-scaling abilities. Ziggs, Veigar, Evelyn, Lissandra, Cassiopea, Rumble, etc. champions deal damage with their abilities based on how much ability power they have. Magic resistance reduces magic damage.
  • The third type of damage is True Damage. This cannot be reduced. True Damage cuts through your health bar, ignoring armor and magic resistance. Although getting more HP can help against a flat amount of true damage. Some champions’ abilities deal true damage like Camille’s Q, Vayne’s passive on her W, Chogath’s R, etc.

What is Armor?

Armor is one of the many stats champions have in League of Legends. Every champion has some base armor at the start that increases with levels, runes, items, or the champion’s passive. Usually, champions gain a small amount of armor per level. ‘Thresh’ has a passive that lets him collect souls to get more armor and ability power. So he doesn’t get armor per level like most other champions. Armor reduces physical damage and increases your effective health pool against attack damage champions.

How Does Armor Work in League of Legends

The amount of physical damage you can reduce with the help of armor can be calculated by the following formula given by Riot.

Post Mitigation Damage League of Legends
Image Source: Riot Games

So having 25 armor, a champion can mitigate the incoming physical damage by 20%. And if a champion has 100 armor, they take 50% reduced damage. This is a simplified representation of armor, considering the opponent does not have anything to reduce or penetrate the armor.

Armor increases the effectiveness of health and shields. Having 100 armor means your effective HP against physical damage is 2 times your actual HP. With 100 armor, a 250 HP shield will take 500 HP worth of damage to break.

Effective Health League of Legends
Image Source: Riot Games

So to have a better bang for your buck, you need to buy health as well as armor to reduce physical damage. For example, having 1000 health and 400 armor count to 4000 effective health against AD champions. On the other hand, 2500 health and 200 armor will equal 5000 effective health against physical damage. Also, most of the time, you will face some magic damage champions on the enemy team. So health gives you some type of defense against them, even if you don’t buy any magic resistance.

How Armor Works in League of Legends
How Armor Works in League of Legends
How Armor Works in League of Legends

Image Source: League of Legends

Penetrating or Negating Armor in League of Legends

There are several ways to reduce or ignore the armor of your opponent.

Armor Reduction

Some champions’ abilities have armor reduction effects. This armor reduction can be flat or percentile. Abilities or passives like Corki’s Gatling Gun and Rell’s Break the Mold have flat armor reduction capabilities, while Jarvan IV’s Dragon Strike and Kog’maw’s Caustic Spittle have percentage armor reduction.

Armor Penetration

Armor penetration works well against enemies with high armor. 30% armor penetration reduced the enemies’ armor by 30%. For example, Rammus with 400 armor will lose 120 if the opponent has 30% armor penetration. Armor penetration stacks multiplicatively. Gangplank’s Powder Keg has 40% armor penetration. Items like Lord Dominik’s Regards have 35% armor penetration.


While armor penetration works well against high armor targets, lethality works wonders against targets with low armor. Lethality penetrates a flat amount of armor. It scales with level and goes up to 100% at level 18, meaning at level 18, if you have 30 lethality you will ignore 30 armor of the enemy. Thus it is good for assassins who want to take out high-priority enemy carries with low resistance. Taking away 40 armor from a 50-60 armor target makes a huge difference, but taking away 40 armor from a Rammus with 300 armor doesn’t amount to much.

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Rifat Mahmood is a former League of Legends writer at GameRiv.