What is internal cooldown in Genshin Impact?

If you consume any Genshin Impact content, you may have heard the term “internal cooldown,” or ICD. Here’s a somewhat simplified explanation of what this means for your characters and why it’s important.

Internal cooldown for elemental application (“elemental ICD” or just “ICD”) refers to the interval of time between elemental hits that apply their element. For example, let’s look at Yoimiya, who can deal Pyro damage with her Normal Attacks.

Yoimiya stands in front of a Cryo enemy and spams Normal Attacks. Her Normal Attack string is a combo of seven hits that all deal Pyro damage. However, only hits 1, 4, and 7 triggered Melt. All of her hits did Pyro damage, but only those specific hits applied the Pyro element to the enemy. So what’s going on?

1. The first hit dealt Pyro damage and applied Pyro to the enemy. After this hit, an internal cooldown came into effect, preventing subsequent hits from applying Pyro again. 
2. The next two hits happened during this cooldown, so they failed to trigger a reaction. 
3. The fourth hit happened after ICD expired, triggering Melt and resetting the cooldown. 
4. Hits five and six occur while ICD is active, dealing Pyro damage but not triggering reactions.
5. The seventh hit applies Pyro and triggers Melt again.

Standard ICD in Genshin Impact

Yoimiya’s Normal Attacks have what we call standard ICD in Genshin Impact, meaning she applies Pyro every three hits or every 2.5 seconds, whichever comes first. In Yoimiya’s case, her Normal Attacks are fast enough that the three-hit condition is met before the 2.5s condition.

It’s also worth noting that every damage source has its own independent ICD. If Yoimiya’s Burst is active at the same time she is doing Normal Attacks, her Burst will also apply Pyro independently of her Normal Attacks.

Understanding these rules provides insight into why characters like Xingqiu are so valuable. Xingqiu’s Burst follows standard ICD rules, but it deals so many hits of Hydro damage that it ends up triggering the three-hit rule extremely often. At Constellation 6, every wave of Xingqiu’s Burst applies Hydro to the enemy. More Hydro application means more reliable reactions, cementing Xingqiu’s place in the meta as one of the best Hydro appliers in Genshin Impact.

Non-standard ICD

Some characters in Genshin Impact have special ICD rules coded into their kits. The most notable example is Xiangling, who has no ICD at all on her Pyronado. Every single Pyronado hit will apply Pyro, regardless of how much time has passed or how many times it has hit the enemy.

This makes Xiangling a powerhouse of a DPS, since she can trigger Vaporize with every single hit of her Burst, provided you have enough Hydro to keep up with her. It also makes her one of the most reliable Pyro appliers for setting up Melt reactions.

Other characters are not so lucky. Collei’s Burst has a special ICD of 3 seconds. Her Burst will only apply Dendro to the enemy every 3 seconds, regardless of how many times it has hit. This special rule actively slows down Collei’s Dendro application, reducing her usefulness in Dendro teams.

Certain chain reactions are unaffected by ICD. Swirl, for example, will apply the Swirled element to the enemy every single time it occurs. Jean and Bennett abuse this rule with their “Sunfire” combo. Bennett’s Burst continuously applies Pyro to the on-field character, and Jean’s Burst continuously applies Anemo to trigger rapid, repeated Pyro Swirls centered on the player. Any enemy caught in these Swirls gets Pyro applied to them, beating out even Xiangling’s rate of Pyro application.

Why is elemental application rate important?

How quickly you can apply an element dictates how many and what kinds of reactions you’re able to perform. If you want a specific character to trigger reactions, you need to make sure that the prerequisite element (the “aura”) is already present on the enemy. 

For example, if Yoimiya wants to trigger Vaporize with her Pyro-infused Normal Attacks, she needs to have a constant Hydro aura on the enemy. Xingqiu or Yelan can reliably provide this Hydro aura with the rapid Hydro application from their Bursts.

In other words, your aura applier should have faster elemental application than your trigger character.

Knowing which characters can apply their element more quickly or more slowly is an integral part of teambuilding in Genshin Impact. Armed with this knowledge, you are free to build more creative teams with more control over your reactions.