Cooldown reduction

Cooldown reduction (abbreviated as CDR) is a champion statistic that reduces the cooldown of abilities, or the amount of time you must wait before an ability can be used again once you activated it, by a percentage.

Cooldown reduction is granted by items, buffs, runes and masteries, as well as some passive abilities.

Cooldown reduction stacks additively. For example, if you have 5% cooldown reduction from masteries and 10% cooldown reduction from, you will have 15% cooldown reduction.
 * Cooldown reduction cannot be increased beyond 40%
 * Unless you have the mastery (raises your cooldown reduction up to 45%)

Cooldown reduction is determined at the moment an ability is activated. Increasing/decreasing your cooldown reduction while the skill is on cooldown will not affect the cooldown.

Cooldown reduction does not apply on item active abilities such as that of or item passive effects with cooldowns such as that of . Most sources of cooldown reduction also do not apply on summoner spells unless specifically stated, e.g. the unique enchantment effect of for boots. Cooldown Reduction does not apply to an Innate Ability of any kind.

Although not a basic item, is the item from which the cooldown reduction gold value is derived. From this item derives a value of approximately per percentage of cooldown reduction. This yields for items with 10% CDR,  for 15% CDR, and  for 20% CDR.

Champion abilities

 * increases her cooldown reduction by 25% at 250 stacks.
 * increases cooldown reduction by %.

Masteries

 * increases cooldown reduction and the cap by %.

Neutral buffs

 * The buff increases cooldown reduction by 10%.

Lowering cooldowns
Some champions have abilities that decrease their cooldowns by a flat amount, either their base cooldown or current cooldown, or entirely refresh their cooldown. Base reduction occurs before cooldown reduction takes effect while flat reduction occurs after cooldown reduction takes effect. By using those, a champion can disregard the 40% cooldown reduction cap.

Note: Only the cooldown reduction of these abilities is shown here, to read more information on each of these abilities, follow the link on each of them.

Base reduction

 * base cooldown is halved if it kills the target.
 * base cooldown is reduced by 1 second if it hits a target, stacking up to 2 times.
 * base cooldown is reduced to seconds while casting inside of.

Flat reduction

 * cooldown is reduced by 2 seconds each time a nearby enemy unit dies.
 * cooldown is reduced by seconds each time Amumu is hit by an attack.
 * reduces all of Ezreal's cooldowns by 1 second if it strikes an enemy unit.
 * cooldown is reduced by 3 seconds if it hits an enemy unit.
 * cooldown is reduced by 1 second for every autoattack.
 * cooldown is reduced by seconds every time she damages an enemy champion with an ability, and by  seconds for a basic attack.
 * reduces all her abilities' cooldowns by 15 seconds whenever an enemy champion dies within 3 seconds of Katarina dealing damage to them.
 * cooldown is reduced by 1 second for each of 's strikes, and by 2 seconds against champions.
 * cooldown is reduced by 1 second for every autoattack.
 * innate cooldown is reduced by 1 second for every autoattack.
 * cooldown is reduced by 1 second for every autoattack.
 * cooldown is reduced by seconds if he manages to pick up his axe after using the ability.
 * reduces his other spells' cooldowns by seconds.
 * cooldown is reduced by seconds for every autoattack.
 * cooldown is reduced by seconds for each successful autoattack, and by 1 second against champions.
 * cooldown is reduced by 1 second if she throws the.
 * 's basic attacks reduce the cooldowns of his basic abilities by seconds, increased to  seconds for  recharge time.
 * cooldown is reduced by 3 seconds upon hitting an enemy.
 * cooldown is reduced by 1 second for every critical strike.
 * reduces his other abilities' cooldowns by 1 second for each strike (for a maximum of 3 seconds reduction).
 * cooldown is reduced by 2 seconds when his hits an enemy champion.
 * innate cooldown is reduced by 4 seconds whenever he uses an ability.
 * on activation, reduces all of Zilean's other basic abilites' cooldowns by 10 seconds.

Percentage reduction

 * cooldown is reduced by % if he can catch it when its return (scales with level).
 * cooldown is reduced by 60% if he picks up his boulder after using the ability.
 * 's passive component allows him to reduce the current cooldown on all of his basic abilities by 70% for every kill or assist he scores.
 * base cooldown is reduced by 70% while it's currently higher if it kills a unit, or if hits an enemy marked as.
 * 's cooldown is reduced by 1% for every he has.
 * 's cooldown is reduced by 50% if it kills a minion or monster.

Cooldown refreshing

 * cooldown is refreshed if the target is afflicted with the Moonlight debuff from.
 * cooldown is refreshed if Draven catches a.
 * cooldown is refreshed if Evelynn gets a champion kill or assist.
 * cooldown is refreshed if it kills a unit.
 * cooldown is refreshed if Kha'Zix gets a champion kill or assist.
 * cooldown is refreshed whenever Tristana gets a champion kill or assist.

Trivia
[Last updated 09/05/2016 on patch 6.9]

One cost and efficient way to reach maximum CDR (45%) is:
 * First of all, by maxing out the mastery which will provide 5% CDR and raise the CDR cap to 45%.
 * Then, by including 10% CDR in your rune pages.
 * Then by buying the which will provide 10% CDR.
 * And finally by purchasing a 20% CDR–item, the cheapest being the.
 * 20% CDR–items:
 * – (cheapeast 20% CDR–item in Howling Abyss)
 * – (cheapeast 20% CDR–item in Howling Abyss)
 * – (cheapeast 20% CDR–item in Howling Abyss)
 * – (cheapeast 20% CDR–item in Howling Abyss)
 * – (cheapeast 20% CDR–item in Howling Abyss)
 * – (cheapeast 20% CDR–item in Howling Abyss)
 * – (cheapeast 20% CDR–item in Howling Abyss)

The most cooldown reduction any champion can obtain at level 1 is 35%. To achieve this you must :
 * Max out the mastery which will provide 5% CDR and raise the CDR cap to 45%.
 * Have the from the  (10% CDR)
 * Have a full CDR rune page:
 * 9 Marks of Cooldown Reduction (9% CDR)
 * 9 Seals of Cooldown Reduction (9% CDR)
 * 9 Glyphs of Cooldown Reduction (9% CDR)
 * 3 Quintessences of Cooldown Reduction (3% CDR)


 * Relevant mathematics:


 * 35%
 * (This value is actually, but in-game value is displayed rounded)

Cooldown reduction Abklingzeitverringerung Reducción de enfriamiento Réduction des délais de récupération Skrócenie czasu odnowienia Сокращение перезарядки 冷却缩减