Internal Cooldown

Internal Cooldown (ICD) is a mechanism that regulates how often an ability can apply an element for elemental reactions or elemental auras on a target.
==Overview==
ICD is counted based on a timer and a hit counter.
For most character abilities, the standard ICD is 2.5 seconds or 3 hits. This means that the ICD is reset either after 2.5 seconds have passed or after 3 hits of the particular move are made. Note:
* The first hit after the 3-hit sequence will apply an element, but does not reset the 2.5 second timer.
* The first hit after the timer will apply an element, reset the timer, and reset the hit sequence.
Some characters' abilities may have special ICDs or no ICD at all. Some ICDs may lack a hit counter, but a timer is always present.
Note that ICD is counted separately for each attacker and each target.
For an in-depth explanation of the properties that handle ICD, see Internal Cooldown/Data.
For example, in Yoimiya's Normal Attack sequence, she will shoot 7 arrows over the course of around 2.5 seconds, and she can infuse her attacks with Pyro by casting her Elemental Skill. When she attacks a Cryo Hypostasis, which has a permanent Cryo aura, because of the ICD, not every shot will trigger a Melt reaction: only the 1st, 4th, and 7th will trigger Melt, as per the 3-hit rule.
Note that the 1st Melt shot will start the ICD 2.5 second timer. The 2nd and 3rd shots do not melt because they were made in less than 2.5 seconds since the 1st shot. Although the 4th shot was also within the 2.5 second window, it melts because of the 3 hit rule (it is the third hit made after the 1st shot).
Moreover, after the 2.5 second timer expires, the next shot Yoimiya makes will Melt, regardless of where in the 3-hit attack sequence Yoimiya is, and start a new 2.5 second timer.
==General Patterns==
* A single character usually has separate ICDs for different abilities or different components of a single talent.
** However, sometimes multiple different abilities will share the same ICD.
Specifically:
* For most Bow, Catalyst and Polearm users, the ICD for Normal and Charged Attacks are separate.
** Exception: For Xiao, the ICDs for Normal and Charged Attacks are shared.
* For most Claymore and Sword users, the ICD for Normal and Charged Attacks are shared.
** Exception: For Kamisato Ayaka and Kamisato Ayato, the ICDs for Normal and Charged Attacks are separate.
* Plunging Attacks do not have ICD.
* The ICD for bow users' charged shots varies between specific characters.
==Notable Examples==
The following is an incomplete list of notable examples and exceptions to the 2.5 seconds/3 hits standard ICD, especially those that inherently hit more than once. For the full list of character abilities and their ICD, see Internal Cooldown/Data.
===No ICD===
* Bennett's Elemental Skill
* Candace's Elemental Burst
* Chongyun's Elemental Burst
* Collei's Elemental Skill
* Diluc's Elemental Skill
* Ganyu's Frostflake Arrow
* Kaedehara Kazuha's Elemental Burst
* Tartaglia's Riptide Slash and Elemental Burst
* Rosaria's Elemental Skill and Elemental Burst
* Sangonomiya Kokomi's Elemental Skill
* Sucrose's Elemental Burst
* Xiangling's Elemental Skill and Elemental Burst
* Xinyan's Elemental Skill
* Yae Miko's Elemental Burst
===Non-Standard ICD===
* Burning: 2s
* Thrusting Charged Attacks by most Polearm users and Kamisato Ayato: 0.5s
* Amber's Fully-Charged Aimed Shot and Fiery Rain: 1s/3 Hits
* Barbara's Melody Loop: 2.5s, 1st and 4th hits apply element
* Collei's Elemental Burst: 3s
* Cyno's Duststalker Bolts: 2.5s
* Diluc's Elemental Burst: 5s/5 Hits
* Dori's Elemental Burst: 3s
* Fischl's Oz Coordinated Attack: 5s/4 Hits
* Nilou's Tranquility Aura: 1.9s/4 Hits
* Tighnari's Clusterbloom Arrows: 2.5s/4 Hits
* Venti's Elemental Burst: 1s/3 Hits
* Yelan's Elemental Burst Coordinated Attacks: 2s/3 Hits
==Notes==
* Elemental application on Water or Grass is not affected by ICD.
==Navigation==
ja:元素付着クールタイム
ru:Время отката наложения статуса
vi:CD Ngầm