A critical strike is a basic attack or ability that deals twice its normal damage.
All basic attacks and some abilities can 
critically strike. Most champions cannot critically strike structures. The exceptions are 
Fiora, 
Jhin, and 
Master Yi.
Most champions have special attack animations for critical strikes. This includes mages and other champions not meant to be built using basic attacks as their main source of damage. Other champions have a sound that plays when they critically strike, typically a grunt of effort.
Champions can increase their chances to critically strike and the damage they deal with critical strikes using items and abilities. Critical strikes are specially valuable for champions who deal damage primarily with basic attacks rather than abilities. Some champions, like 
Ashe, have an affinity for critical strikes and benefit more than others from items that improve them.
Critical strike chance
Critical strike chance is the chance that a basic attack of a champion critically strikes. Every champion starts with 0% critical strike chance, and level-ups do not increase the critical strike chance.
Critical strike chance can be increased with items and abilities; it 
stacks additively, and each bonus point acquired directly affects its statistic. It cannot be increased beyond 100%, although some effects will benefit from the stat despite the cap.
Gold Value
: The critical strike chance has a gold value of 
40 per point.
The critical strike chance changes dynamically depending on the number of basic attack that didn't critically strike. For example, if you have a 30% critical strike chance you guaranteed to have 30 or more attacks that critically strike per 100 attacks. If you don't critically strike for a long time your next attacks have a higher chance of critically strkining.
When averaged over a large number of autoattacks critical strike chance is essentially a damage multiplier. At base critical damage (100% bonus damage) each 1% of critical chance adds 1% bonus damage. For example, the damage dealt with autoattacks by a champion with 50% critical strike chance and base critical damage is on average 150% of the damage he would deal if he had 0% critical strike chance. For this reason the critical strike chance scales well with both attack damage and attack speed. The formula for this damage multiplier is:
- Damage multiplier = 1 + (Critical chance × (1 + Bonus critical damage))
Increasing critical strike chance
Items
| Item | Cost | Amount | Availability |
|---|---|---|---|
 Cloak of Agility | 800 | 20 % | All maps |
 Essence Reaver | 3300 | 25 % | All maps |
 Infinity Edge | 3400 | 25 % | All maps |
 Molten Edge | 3400 | 25 % | All maps |
 Phantom Dancer | 2600 | 25 % | All maps |
 Rapid Firecannon | 2600 | 25 % | All maps |
 Runaan's Hurricane | 2600 | 25 % | All maps |
 Statikk Shiv | 2600 | 25 % | All maps |
 Stormrazor | 3200 | 25 % | All maps |
 Zeal | 1400 | 25 % | All maps |
Champion abilities
Critical strike chance as scaling
Some game elements scale with the champion's amount of critical strike chance.
Champion abilities
Modifying critical strike damage
General
- By default, critical strikes deal 200% of the normal damage (twice as much).
- In most cases, critical strike damage
stacks additively.
- Damage modifiers apply to critical strike damage normally.
Champion abilities
- Ashe's Frost Shot
- Fiora's Bladework
- Jhin's Whisper
- Senna's Absolution
- Shaco's Deceive when used to Backstab
- Yasuo's Way of the Wanderer
- Yone's Way of the Hunter
Items
Guaranteed critical strikes
Some game elements can critically strike with no dependence on critical strike chance.
Champion abilities
- Ashe's Volley
- Fiora's Bladework's second attack
- Jhin's Whisper's fourth attack and Curtain Call's fourth shot
- Kindred's Mounting Dread against low health enemies
- Shaco's Deceive when used to Backstab
- Talon's Noxian Diplomacy when close to his target
Game elements that can critically strike
Champion abilities
- Basic attack modifiers
Many abilities in the game enhance basic attacks, causing them to deal increased damage. Since these are basic attacks, they can critically strike, with a few exceptions (see below), however, the ability damage itself will only be amplified by a critical strike for the following abilities.
- Aphelios' Infernum and Crescendum
- Darius' Crippling Strike
- Galio's Colossal Smash
- Graves' New Destiny
- Jayce's Hyper Charge
- Jinx's Switcheroo!
- Lucian's Lightslinger
- Master Yi's Double Strike
- Nasus' Siphoning Strike (only the base damage)
- Nocturne's Umbra Blades (only to primary target)
- Pantheon's Shield Vault with Mortal Will empowered basic attacks
- Rek'Sai's Queen's Wrath (only to primary target)
- Riven's Runic Blade
- Shaco's Backstab and Deceive with Backstab
- Shyvana's Twin Bite
- Volibear's Thundering Smash
- Xin Zhao's Three Talon Strike
- Other abilities
- Aphelios' Onslaught, Duskwave, Sentry and Moonlight Vigil
- Gangplank's Parrrley and Powder Keg
- Garen's Judgment
- Kayle's Fire Waves and Starfire Spellblade (while Aflame)
- Master Yi's Alpha Strike
- Miss Fortune's Double Up and Bullet Time
- Samira's Flair and Inferno Trigger
- Sivir's Ricochet
- Twitch's Spray and Pray
- Vi's Excessive Force
- Yasuo's Steel Tempest
- Yone's Mortal Steel
Items
Some items that deal bonus damage can critically strike if the basic attack that triggers them critically strikes.
Exceptions
- Camille's Precision Protocol - both enhanced attacks cannot critically strike.
- Fiora's Bladework - the first attack cannot critically strike, and the second attack will also critically strike turrets.
- Jhin's Whisper - the fourth attack can critically strike turrets.
- Sylas' Petricite Burst, Twisted Fate's Pick a Card and Zac's Stretching Strikes - enhanced attacks cannot critically strike.
Others
- Tryndamere's Spinning Slash reduces its cooldown when critically striking enemies.
- Yasuo's Last Breath grants all critical strikes armor penetration against bonus armor.
Cosmetic critical strikes
Some abilities are displayed as a critical strike under certain circumstances but do not interact with critical strike chance, Infinity Edge, or 
Randuin's Omen. These are use for cosmetic purposes to indicate high amounts of, empowered, or otherwise significant damage on an ability.
- Aatrox's The Darkin Blade far end of the first two casts, center of the third
- Anivia's Frostbite's enhanced damage
- Evelynn's Empowered Whiplash and Last Caress' empowered damage
- Fiddlesticks' Terrify's doubled damage against targets that have already been terrified recently.
- Gnar's GNAR! if enemies hit terrain
- Gragas' Barrel Roll's enhanced damage
- Karthus' Lay Waste against a single target
- Kog'Maw's Living Artillery against enemies under 40% of their maximum health
- LeBlanc's Sigil of Malice, Distortion, and Ethereal Chains against a target marked by Sigil of Malice
- Lillia's Watch Out! Eep! against enemies in the center
- Malphite's Thunderclap
- Mordekaiser's Obliterate against a single target
- Nidalee's Takedown against Hunted enemies
- Pantheon's Comet Spear against enemies under 20% of their maximum health
- Pyke's Death from Below if it executes a champion
- Qiyana's Elemental Wrath (Terrain) if it hits a target under 50% of their maximum health
- Ryze's Overload against Fluxed enemies
- Samira's Taunt
- Shaco's Two-Shiv Poison if used against a low-health target
- Sett's The Show Stopper and Haymaker to all units hit in the center
- Swain's Demonflare with maximum damage
- Urgot's Fear Beyond Death if it executes a champion
- Vayne's Condemn if the target hits terrain
- Vladimir's Transfusion with Crimson Rush
- Volibear's Frenzied Maul on a wounded target and Stormbringer
- Ziggs' Satchel Charge if used to Hexplode a turret
- Rift Herald's leap attack against a turret
Trivia
- In many MMO settings, a number of attack damage-based assassins or secondary assassin-based champions also benefit from high critical strike chance in varying forms, as a means to help finish off targets faster as well as to deal more damage in bursts overall.
- Some champions may actually use their critical strike animation for their empowered-basic attack if they ever activate a single-use on-hit effect, only it does not actually count as an actual critical strike.
| Offensive |  Ability power ·  Attack damage ·  Attack speed ·  Critical strike chance ·  Critical strike damage ·  Armor penetration ·  Magic penetration ·  Life steal ·  Spell vamp ·  True damage
|
|---|---|
| Defensive |   Heal and shield power ·  Health ·  Health regeneration ·  Armor ·  Magic resistance ·  Tenacity ·  Slow resist
|
| Utility |  Cooldown reduction ·  Energy ·  Energy regeneration ·  Mana ·  Mana regeneration
|
| Other |  Experience ·  Gold generation ·  Movement speed ·  Range
|
