Armor in League of Legends – How Armor Penetration and Armor Works

Did you know a champion with -15 armor takes more damage than one with 0 armor? This shows how complex armor mechanics are in League of Legends. Knowing how armor and penetration work is key to being effective on the Rift.

Armor in League of Legends is a vital defense against physical damage in League of Legends. It’s a part of what makes champions strong. Whether you’re a tank or a carry, understanding armor is important.

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League of Legends armor stats are more than just numbers. They interact with items, abilities, and champion levels. This guide will show you how armor value affects gameplay and how to build your champions.

This guide covers everything from damage reduction to armor penetration. You’ll learn how to use armor to your advantage. You’ll also find out how to build or counter armor-heavy teams.

Key Takeaways

  • Negative armor values result in increased damage taken
  • Armor effectiveness varies based on total armor and enemy penetration
  • Lethality provides flat armor penetration at all levels
  • Percentage armor reduction is more impactful against high-armor targets
  • Understanding armor mechanics is key for optimal builds and champion selection

Understanding Armor Mechanics in League of Legends

Armor is very important in League of Legends. It helps your champion defend against physical damage. Let’s explore how armor works and its impact on your gameplay.

Base Armor vs Bonus Armor

In League of Legends, there are two types of armor: base and bonus. Base armor increases as your champion levels up. Bonus armor comes from items, runes, and abilities. Knowing the difference is essential for a strong defense.

How Armor Reduces Physical Damage

Armor helps reduce physical damage you take. Each armor point boosts your effective health by 1%. This makes your champion harder to defeat.

ArmorDamage ReductionEffective Health Increase
2520%25%
10050%100%
20066.6%200%

Armor is a defensive stat that reduces incoming physical damage. When a champion takes physical damage, their armor reduces that damage before it affects their health pool. Here’s how it works:

Basic Concept:

  • Armor converts incoming physical damage (pre-mitigation) into a lower amount (post-mitigation)
  • The higher your armor, the more physical damage you can absorb
  • Each point of armor effectively increases your health by 1% against physical damage

Damage Calculation:
For positive armor values (which is most common), the formula is:

Post-mitigation damage = Physical damage × (100 / (100 + Armor))  

For example:

  • If you have 100 armor and take 1000 physical damage
  • The actual damage you receive would be: 1000 × (100 / (100 + 100)) = 500 damage

Effective Health:
You can think of armor as a way to make your health pool more effective against physical damage. For instance:

  • A champion with 1000 health and 100 armor
  • Has an effective health pool of 2000 against physical damage
  • Because each point of armor adds 1% to your effective health

This makes armor particularly valuable when combined with high health totals, as they multiply each other’s effectiveness.

Examples using 1000 health and 1000 pre-mitigation damage, for the sake of simplicity:

  • 25 Armor
    • 25% effective health increase → 1000 nominal health becomes 1000 × (1 + 25 ÷ 100) = 1000 × 1.25 = 1250 total effective health against physical damage
    • 1000 raw damage ÷ (1 + 25 ÷ 100) = 1000 ÷ 1.25 = 800 post-mitigation damage → 20% total physical damage reduction
  • 100 Armor
    • 100% effective health increase → 1000 nominal health becomes 1000 × (1 + 100 ÷ 100) = 1000 × 2 = 2000 total effective health against physical damage
    • 1000 raw damage ÷ (1 + 100 ÷ 100) = 1000 ÷ 2 = 500 post-mitigation damage → 50% total physical damage reduction
  • 200 Armor
    • 200% effective health increase → 1000 nominal health becomes 1000 × (1 + 200 ÷ 100) = 1000 × 3 = 3000 total effective health against physical damage
    • 1000 raw damage ÷ (1 + 200 ÷ 100) = 1000 ÷ 3 = 333.3 post-mitigation damage → 66.6% total physical damage reduction

Armor Scaling and Effectiveness

Armor increases your effective health linearly. For example, 100 armor doubles your health against physical damage. This makes stacking armor a strong strategy for tank champions.

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Armor Penetration and Reduction Systems

League of Legends armor penetration systems are complex but key for better damage. Knowing these mechanics can boost your gameplay and strategy.

Flat Armor Penetration and Lethality

Flat armor penetration cuts a target’s armor by a set amount. Lethality, its advanced form, grows with your champion’s level. At level 18, 18 lethality means 18 flat armor penetration. It’s great against weak targets with little armor.

Percentage Armor Penetration

Percentage armor penetration takes a part of the target’s armor. For example,Lord Dominik's Regard item icon Lord Dominik’s Regards gives 35% armor penetration. This is super useful against heavily armored foes.

Armor Reduction Effects

Armor reduction is different from penetration. It lowers the target’s actual armor. This can be done through abilities or items and can even make armor go below zero, increasing physical damage.

Order of Calculations

The game follows a specific order for applying armor penetration and reduction:

  1. Flat armor reduction
  2. Percentage armor reduction
  3. Percentage armor penetration
  4. Flat armor penetration (Lethality)

Knowing this order is key for a good build strategy. Mixing percentage and flat penetration can be very effective against both tanky and squishy opponents.

ItemAttack DamageArmor Penetration
Duskblade of Draktharr League of Legends Item Icon Duskblade of Draktharr6018 Lethality
Mythic item, Eclipse icon Eclipse5518 Lethality
Vintage looking handgun - The Collector Icon The Collector5512 Lethality
Lord Dominik's Regard item icon Lord Dominik’s Regards4035% Armor Penetration

Don’t forget, armor penetration runes can also boost your damage. Try out different setups to find what works best for you and your champion.

Armor in League of Legends: Items and Build Strategies

Building armor in League of Legends can change the game. The right armor items can shift the battle’s outcome, helping tanks and frontliners. Let’s explore some key armor choices and when to use them.

Core Armor Items

Dead Mans Plate League of Legends Item Icon Dead Man’s Plate is great for champions who need to close gaps quickly. It has 50 armor and 300 health, perfect for initiators.Legendary Item - Frozen Heart icon Frozen Heart, with 100 armor, is ideal against enemies that rely on attack speed.

Randuin's Omen Icon Randuin’s Omen is the best choice against crit-heavy teams. It has 70 armor and a unique passive.

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Situational Armor Choices

Lol Item Thornmail Icon Thornmail is the top pick against teams that rely on healing. It offers 75 armor and reduces healing.sunfire cape item icon Sunfire Cape, with 40 armor and AOE damage, is perfect for tanks who want to deal damage while taking hits.

When to Prioritize Armor vs Health

Deciding between armor and health depends on the enemy team. Against physical damage dealers, go for armor. For mixed damage, balance both. Early game, health is more efficient, but armor becomes more valuable later.

ItemArmorHealthCostBest For
Dead Mans Plate League of Legends Item Icon Dead Man’s Plate503002900Initiators
Legendary Item - Frozen Heart icon Frozen Heart10002700vs Attack Speed
Randuin's Omen Icon Randuin’s Omen703003000vs Crit
Lol Item Thornmail Icon Thornmail7502700vs Healing
sunfire cape item icon Sunfire Cape403002750AoE Damage

Investing in armor is best when you already have good health. For damage dealers, a mix of offense and defense is often better than just armor.

ItemCostArmorAvailability
LoL item Aegis of the Legion Icon Aegis of the Legion1100 25Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Epic item Bramble Vest Bramble Vest800 30Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Chain Vest Icon Chain Vest800 40Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
Icon of League of Legends starting item Cloth Armor Cloth Armor300 15Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Cruelty Icon Cruelty0 30Arena
LoL Item Darksteel Talons Icon Darksteel Talons0 55Arena
Dead Mans Plate League of Legends Item Icon Dead Man’s Plate2900 55Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
Bloody greatsword, death's dance Death’s Dance3300 50Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Eleisa's Miracle Icon Eleisa’s Miracle0 65Arena
Legendary Item - Frozen Heart icon Frozen Heart2500 75Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
Legendary Item - Gargoyle Stoneplate icon Gargoyle Stoneplate0 65Arena
LoL Item Glacial Buckler Icon Glacial Buckler900 25Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
Guardian Angel icon Season 11 Art Guardian Angel3200 45Arena, Classic Summoner’s Rift 5v5
Full Build Iceborne Gauntlet icon Iceborn Gauntlet2900 50Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
League of Legends Item Jak'Sho the Protean Icon Jak’Sho, The Protean3200 45Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Knight's Vow Icon Knight’s Vow2300 40Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
Mythic Item - Locket of the Iron Solari icon Locket of the Iron Solari2200 25Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Plated Steelcaps Plated Steelcaps1200 25Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Radiant Virtue Icon Radiant Virtue0 35Arena
Randuin's Omen Icon Randuin’s Omen2700 75Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Seeker's Armguard Icon Seeker’s Armguard1600 25Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Shattered Armguard Icon Shattered Armguard1600 25Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Shield of Molten Stone Icon Shield of Molten Stone0 100Arena
LoL Item Steel Sigil Icon Steel Sigil1100 30Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
Mythic Item - Sunfire Aegis icon Sunfire Aegis2700 50Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL ItemTalisman of Ascension Icon Talisman of Ascension0 0Arena
LoL Item The Golden Spatula Icon The Golden Spatula0 40Arena
Lol Item Thornmail Icon Thornmail2450 75Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Trailblazer Trailblazer2400 40Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Unending Despair Unending Despair2800 25Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
LoL Item Vigilant Wardstone Icon Vigilant Wardstone2300 25Classic Summoner’s Rift 5v5
LoL Item Warden's Mail Icon Warden’s Mail1000 40Nexus Blitz, Classic Summoner’s Rift 5v5, All Random All Mid
A golden cube with an orb - Watchful Wardstone icon Watchful Wardstone1100 10Classic Summoner’s Rift 5v5
LoL Item Wooglet's Witchcap Icon Wooglet’s Witchcap0 50Arena
Zekes convergence full item build Zeke’s Convergence2300 30Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid
League of Legends item Zhonya Hourglass Zhonya’s Hourglass3250 50Nexus Blitz, Arena, Classic Summoner’s Rift 5v5, All Random All Mid

How Armor Stacking Works

Armor stacking is a straightforward but powerful mechanic. Each point of armor increases your effective health against physical damage by 1%. This creates a linear scaling that never diminishes in value.

The Formula:

Effective Health = (1 + Armor/100) × Base Health  

Simple Example:

  • Champion has 1000 base health and 60 armor
  • Effective health = (1 + 60/100) × 1000
  • Effective health = 1.6 × 1000 = 1600

This means enemies need to deal 1600 physical damage to defeat this champion, even though they only have 1000 health.

Key Points:

  • Each armor point consistently adds 1% effective health
  • There are no diminishing returns
  • The value of armor remains constant regardless of how much you already have

Special Case – Negative Armor:

  • Negative armor works differently
  • Cannot reduce effective health below 50% of base health
  • Example: -100 armor results in 66.67% effective health
  • This is rare and usually only happens with specific debuffs

This makes armor a reliable defensive stat that scales well throughout the game, especially when combined with health items.

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Optimal Balance Between Armor and Health

The ideal balance between armor and health follows these formulas:

  • For Armor: Health = 7.5 × (armor + 100)
  • For Magic Resistance: Health = 6.75 × (magic resistance + 100)

When to Buy What

Early Game:

  • Health is typically more gold-efficient early
  • This assumes you’re facing primarily one damage type
  • If enemies have mixed damage (physical and magical), health becomes even more valuable

Key Factors to Consider:

  1. Healing Efficiency
  • More armor makes healing more effective
  • Each point of health healed becomes more valuable with higher resistances
  1. Damage Types
  • Health helps against all damage types
  • Consider enemy team composition:
    • Mixed damage → Favor health
    • Burst damage → Health can be better
    • True damage → Favor health (armor doesn’t help)
    • Percent health damage → Favor resistances
  1. Champion-Specific Factors
  • Built-in defensive abilities (like Leona’s Eclipse)
  • Health-scaling abilities (like Cho’Gath’s Feast)
  • Healing or shield abilities in your kit
  1. Enemy Team Composition
  • Armor penetration items → Might favor health
  • Sustained damage → Consider healing/vampirism
  • Burst damage → Raw health pool matters more
  1. Item Priorities
  • Sometimes you need specific items for their unique effects
  • These might not follow the optimal health/armor ratio but are still necessary

Remember that this is a general guide, and specific game situations might require different approaches to defensive itemization.

Champion Abilities and Armor Interactions

In League of Legends, champions’ abilities can change how armor works. These changes can greatly affect how you play, both offensively and defensively. Let’s look at some examples of how champions can alter armor values.

Icon showing the League of Legends Champion Darius  Darius, the Hand of Noxus, has a special ability called Apprehend. It gives him up to 25% bonus armor penetration. This lets him break through enemy defenses easily.

Yasuo‘s Last Breath, on the other hand, gives him 50% armor penetration against bonus armor. This makes him very dangerous to tanky opponents.

Some champions can reduce the armor of enemies nearby.LoL Champion Trundle Icon Trundle‘s ultimate ability can take armor from a target, making him stronger.Icon showing LoL Champion Rengar Rengar‘s Empowered Battle Roar also lowers the armor of enemies around him, setting up powerful combos.

A list of champions whose abilities interact with armor includes:

  • Icon showing the League of Legends Champion Malphite  Malphite: Gains bonus armor from his passive
  • LoL Champion Rammus Icon Rammus: Transforms armor into attack damage
  • Icon showing the League of Legends Champion Leona  Leona: Increases her armor and magic resist with Eclipse
  • LoL Champion Taric Icon Taric: Grants bonus armor to himself and allies

Understanding these armor interactions is key to using your champion’s abilities to the fullest. Whether you want to break through enemy defenses or strengthen your own, knowing how abilities affect armor can give you a big advantage on the Rift.

Conclusion

Understanding armor in League of Legends is key to mastering defense and countering enemies. Armor scaling is important, with base armor at level 18 ranging from 87 for Kassadin to 149.4 for Mega Gnar. Each armor point boosts your health by 1%, making it vital for staying alive.

Armor penetration is essential for offense. Items like Thornmail, costing 2450 gold, offer strong defense. Remember, armor’s effect drops off after 200 points. Each point after that reduces damage by less than 1%, so balance is important.

Knowing these armor mechanics helps you make better choices in champion select and itemization. Whether you’re taking damage, boosting carry, or supporting your team, this knowledge improves your game. Stay updated on League of Legends’ armor system to excel in your matches.

FAQ

What is armor in League of Legends?

Armor in League of Legends is a defensive stat that reduces incoming physical damage. Every champion has a certain amount of base armor, which increases with level. Bonus armor can be obtained through items, runes, and abilities. Armor increases the effective health of a champion against physical damage, making them more durable in combat.

How does armor reduce physical damage?

Armor reduces physical damage through a formula that calculates damage reduction. The formula is: Damage reduction = Armor / (100 + Armor). For example, 100 armor provides 50% damage reduction, meaning a champion with 100 armor takes only half the physical damage they would normally receive. This calculation applies to all sources of physical damage, including auto-attacks and physical abilities.

What is the difference between base armor and bonus armor?

Base armor is the innate armor a champion has without any items or runes. It increases naturally as the champion levels up. Bonus armor is any additional armor gained from items, runes, or abilities. Some abilities and items specifically interact with base armor or bonus armor, making the distinction important for certain champion interactions and item choices.

How does armor penetration work in League of Legends?

Armor penetration lets champions bypass some of their target’s armor. There are two types: flat penetration (now called Lethality) and percentage penetration. Flat penetration is better against low-armor targets, while percentage penetration works against heavily armored foes.

What is Lethality and how does it differ from flat armor penetration?

Lethality is a stat that converts into flat armor penetration. It’s designed to be balanced throughout the game, unlike the old flat armor penetration system.

How does armor scaling work in League of Legends?

Armor scaling shows how well armor reduces damage as you get more. Each armor point increases your health against physical damage. But, the damage reduction per point decreases as you stack more armor.

When should I prioritize building armor over health?

Prioritize armor against physical damage threats. But, a mix of health and armor is best. Health works against all damage types, and some effects damage based on max health.

How do champion abilities interact with armor?

Some champions have abilities that give bonus armor, reduce enemy armor, or provide armor penetration. Knowing these interactions helps maximize your champion’s effectiveness and counter enemy strategies.

What are some effective ways to counter armor stacking in League of Legends?

To counter armor stacking, build items with percentage armor penetration. Use champions with armor reduction abilities. Or, focus on magic damage, which armor doesn’t mitigate.

How does armor affect my effective health in League of Legends?

Armor boosts your effective health against physical damage. Each armor point increases your health pool against physical damage by 1%. This makes you harder to take down with physical attacks.

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