Template:Merge from 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 
Stinger, you will have 15% cooldown reduction. Cooldown reduction cannot be increased beyond 40%.
One cost and mastery efficient way to achieve max CDR is to max out the 
Sorcery mastery (5%) and purchase any 20% reduction item and the 
Ionian Boots of Lucidity (15%), giving a total of 40% CDR. The cheapest is the Ionian Boots and 
Morellonomicon (2200G).
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 
Deathfire Grasp or item passive effects with cooldowns such as that of 
Guardian Angel. Most sources of cooldown reduction also do not apply on summoner spells unless specifically stated, e.g. the unique enchantment effect of 
Distortion for boots. Cooldown Reduction does not apply to an Innate Ability of any kind.
Increasing cooldown reduction
Items
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Variable Availability
- Item availability needs updating. Template:Ile
- Summoner's Rift, Howling Abyss Template:Ile
- All maps Template:Ile
- Twisted Treeline Template:Ile.
- Summoner's Rift Template:Ile
- Summoner's Rift, Twisted Treeline, Howling Abyss Template:Ile
- Summoner's Rift, Twisted Treeline, Howling Abyss Template:Ile
- Summoner's Rift, Twisted Treeline, Howling Abyss Template:Ile
Champion abilities
Ryze's Overload increases cooldown reduction by 2 / 4 / 6 / 8 / 10%.- Viktor's Augment: Gravity increases cooldown reduction by 10%.
- Zyra's Rampant Growth increases cooldown reduction by 2 / 4 / 6 / 8 / 10%.
Masteries
- Sorcery increases cooldown reduction by 1.25 / 2.5 / 3.75 / 5%.
- Intelligence increases cooldown reduction by 2 / 3.5 / 5%.
Runes
- Template:Rune and Template:Rune runes increase cooldown reduction.
Neutral buffs
- The Crest of the Ancient Golem 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
- Cassiopeia's Twin Fang base cooldown is reduced to 0.5 seconds if the target is poisoned.
- Darius' Crippling Strike base cooldown is reduced by 1 second for every stack of Hemorrhage on the target.
- Hecarim's Rampage base cooldown is reduced by 1 second if it hits a target. (Stacks up to 2 times)
Flat reduction
- Alistar's Triumphant Roar cooldown is reduced by 2 seconds each time a nearby enemy unit dies.
- Amumu's Tantrum cooldown is reduced by 0.5 seconds each time Amumu is hit by an attack.
- Ezreal's Mystic Shot reduces all of Ezreal's cooldowns by 1 second if it strikes an enemy unit.
- Gragas' Body Slam cooldown is reduced by 3 seconds if it hits an enemy unit.
- Graves' Quickdraw cooldown is reduced by 1 second for every autoattack.
- Karma's Mantra cooldown is reduced by 2 seconds for every skill that hits an enemy champion, and also half of it (1 second) for autoattacks against enemy champions.
- Katarina's Voracity reduces all her abilities' cooldowns by 15 seconds whenever she gets a kill or an assist.
- Master Yi's Alpha Strike cooldown is reduced by 1 second for every autoattack.
- Nocturne's Umbra Blades innate cooldown is reduced by 1 second for every autoattack
- Olaf's Reckless Swing cooldown is reduced by 1 second for every autoattack.
- Olaf's Undertow cooldown is reduced by 4.5 seconds if he manages to pick up his axe after using the ability.
- Ryze's Arcane Mastery allows him to reduce all of his other abilities' cooldowns by 1 when he uses an ability.
- Shen's Ki Strike cooldown is reduced by 1 second every time Shen autoattacks, or by 2 seconds every time Shen autoattacks while Feint's shield is up.
- Shyvana's Twin Bite cooldown is reduced by 0.5 seconds for every autoattack.
- Skarner's Crystal Slash cooldown is reduced by 0.5 seconds for each successful autoattack. (doubled against champions)
- Syndra's Force of Will cooldown is reduced by 1 second if she throws the .
- Taric's Gemcraft reduces Taric's cooldowns by 2 seconds on his next autoattack after using an ability.
- Thresh's Death Sentence cooldown is reduced by 3 seconds upon hitting an enemy.
- Tryndamere's Spinning Slash cooldown is reduced by 1 second for every critical strike.
- Xin Zhao's Three Talon Strike reduces his other abilities' cooldowns by 1 second for each strike.
- Zed's Living Shadow cooldown is reduced by 2 seconds when his hits an enemy champion.
- Ziggs' Short Fuse innate cooldown is reduced by 4 seconds whenever he uses an ability.
- Zilean's Rewind on activation, reduces all of Zilean's other cooldowns by 10 seconds.
Percentage reduction
- Master Yi's Highlander'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.
- Soraka's Starcall reduces Astral Blessing's cooldown by 5 / 6.25 / 7.5 / 8.75 / 10%.
- Yasuo's Steel Tempest's cooldown is reduced by 1% for every 1.72% bonus attack speed he has.
Cooldown refreshing
- Diana's Lunar Rush cooldown is refreshed if the target is afflicted with the Moonlight debuff from Crescent Strike.
- Draven's Blood Rush cooldown is refreshed if Draven catches Spinning Axe.
- Evelynn's Dark Frenzy cooldown is refreshed if Evelynn gets a champion kill or assist.
- Fiora's Burst of Speed cooldown is refreshed whenever Fiora gets a champion kill, and is reduced by half when she gets an assist.
- Irelia's Bladesurge cooldown is refreshed if it kills a unit.
- Kha'Zix's Evolved Wings cooldown is refreshed if Kha'Zix gets a champion kill or assist.
- Lucian's Relentless Pursuit cooldown is refreshed if Lucian gets a champion kill while using The Culling.
- Tristana's Rocket Jump cooldown is refreshed whenever Tristana gets a champion kill or assist.
| Offensive |  Ability power ·  Attack damage ·  Attack speed ·  Critical strike chance ·  Critical strike damage ·  Armor penetration ·  Magic penetration ·  Life steal ·  Omnivamp · Physical vamp ·  True damage
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|---|---|
| Defensive |  Heal and shield power ·  Health ·  Health regeneration ·  Armor ·  Magic resistance ·  Tenacity ·  Slow resist
|
| Utility |  Ability haste ·  Energy ·  Energy regeneration ·  Mana ·  Mana regeneration  Movement speed ·  Range
|
| Other |  Experience ·  Gold generation
|