- For the successor stat, see ability haste.
Cooldown Reduction (abbreviated as CDR) is a champion statistic that either reduces the cooldown of champion abilities, or the amount of time before an ability can be used again after activation, by a percentage. This stat is tracked and can be seen in the champion stats tooltip. This cooldown reduction is different than the cooldown reduction for summoner spells and items, with the value not being visibly tracked in game. Items and runes may reduce the cooldown for summoner spells and other items.
Cooldown reduction is determined at the moment an ability is activated. Increasing or decreasing cooldown reduction while the skill is on cooldown will not affect the cooldown.
Based on the type of cooldown reduction, it can affect:
- Champion ability cooldowns. (e.g. )
- Item active effects. (e.g. ).
- Item passive effects with cooldowns. (e.g. ).
- Summoner spells. (e.g. )
Cooldown reduction does not apply to the following:
- 1 Increasing cooldown reduction
- 2 Champion Abilities
- 3 Other Cooldown Reduction
- 4 Trivia
Increasing cooldown reduction
Unnamed Cooldown Reduction
Various items granted cooldown reduction.
Named Cooldown Reduction
- Unique – Haste: Grants an additional 10% cooldown reduction.
Some champions have abilities that decrease their cooldowns by a flat amount, or by a percentage, affecting either their base cooldown or current cooldown, or some abilities can completely 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 circumvent the 40% cooldown reduction cap.
- Depending on built-in reduction type:
- Base (applies before CDR)
- Flat (applies after CDR)
- Percent (applies to base / current / total cooldown)
- Refresh (cooldown is immediately reduced to 0)
- (rank 3)
Other Cooldown Reduction
|Ultimate ability haste|
- and stack additively with each other while normal CDR stacks multiplicatively with them.
|Active Item CDR|
- and stack additively with each other.
- Multiple copies of the same active ability item, and unique named active share a global cooldown.
- Purchasing yet another copy while the already owned ones are still on CD will make the newest one's sync up with the others'.
- Only 1 rune in the entire game has a way to reduce its cooldown. That rune being , which gets it's cooldown reduced by a percentage whenever the user deals ability damage to an enemy champion and Arcane Comet is on cooldown.
Last updated: December 15th, 2019 – V9.24
One cost and efficient way to reach maximum CDR (45%) is:
- Having both and , and reaching level 10, giving 15% CDR.
- Then by buying the which will provide 10% CDR.
- And finally by purchasing a 20% CDR–item.
- Have the rune which will provide 5% CDR.
- Have the from the (10% CDR)
- Relevant mathematics:
- + = 15%