Elemental Reactions

Elemental Reactions are triggered by applying certain combinations of elemental effects on a target (monster or player). Elemental effects linger for around 9–12 seconds depending on what applied them. They are also removed by Elemental Reactions, though an effect can last after a reaction depending on which skill applied it and which reaction took place.^[1] Reactions have no cooldown, but skills have internal cooldowns before being able to reapply their elemental effect.^[2]

Overview

Elemental Reactions have the following effects:

Elemental Reactions
Second Element	First Element
Second Element
	—	Reverse Vaporize (1.5x DMG)	Overloaded	Melt (2x DMG)	Swirl	Crystallize	Burning
	Vaporize (2x DMG)	—	Electro-Charged	Frozen			—
	Overloaded	Electro-Charged	—	Superconduct
	Reverse Melt (1.5x DMG)	Frozen	Superconduct	—
	Swirl				—
	Crystallize				—
	Burning	—					—

Elemental Reaction damage can be increased by the Elemental Mastery of the character causing the reaction. The in-game interface shows the damage bonus provided by the character's current elemental mastery. This bonus will be applied in different ways, depending on the type of reaction.

Notable sources of Elemental Mastery include:

Instructor's set's 4-piece set bonus grants +120 elemental mastery for the team when the character with the set equipped causes an Elemental Reaction.
Sucrose's passive talents (Catalyst Conversion, Mollis Favonius) can provide elemental mastery to other team members.
Some characters, such as Lisa, gain elemental mastery as a specialized stat starting at their 2nd Character Ascension.

Transformative Reactions

Overloaded, Electro-Charged, Superconduct and Swirl predicted base damage comparison.^[4] Don't be fooled by the difference in the comparison. Swirl and Superconduct have significant effects, and Electro-Charged procs twice.

Transformative Reactions include Overloaded, Shattered, Electro-Charged, Superconduct and Swirl.
These reactions have a base damage determined by the level of the character triggering the reaction.
This base damage is then multiplied by a percentage determined by the Elemental Mastery of the character. The percentage can be seen in-game in the Details section of the Attributes page.

The damage from these reactions cannot crit and is only based on level, meaning ATK, Crit Rate and Crit Damage have no impact. However, the damage is affected by the target's elemental resistance.
Since Superconduct has the lowest base damage, the other reactions can be expressed in multiplicative term of Superconduct base damage. For Superconduct, Swirl, Electro-Charged, Shattered and Overloaded, these values are approximately 1: 1.2: 2.4: 3: 4 respectively. So it can be said, for example, that Overloaded base damage is approximately 4x Superconduct base damage (all other factors being equal).^[5]^[6]
The reaction damage will be an additional instance of damage on top of the damage from the skill, making it difficult to discern due to the overlapping damage displayed values.

Amplifying Reactions

Amplifying Reactions include Vaporize and Melt.
Unlike transformative reactions, Melt and Vaporize replace the damage of the attack/s that triggered them.
These reactions multiply damage of existing attacks by either 1.5x or 2x depending on which element triggers the reaction.
Damage from these reactions can be critical and considers the target's elemental resistance.
The damage is multiplied again by a percentage determined by the Elemental Mastery of the character. The percentage can be seen in-game in the Details section of the Attributes page.
The bonus % to Vaporize and Melt is roughly half of that to Overloaded, Superconduct, Electro-Charged, Shattered, and Swirl, though the damage being multiplied can be much greater than the base damage of the other reactions.
1.5x reactions will tend to preserve the initial element for multiple hits, while 2x reactions will tend to immediately remove the initial element.^[1]

Order of Application

Triggering element is displayed on the left, while the initial element is displayed on the right.

If an amount of damage results from an Elemental Reaction, its damage scales with the level of the character who applies the last element, as well as their elemental mastery, and is reduced by enemy elemental resistance. The triggering element will be displayed on the left of reaction animation over enemy's head, while the base element will be displayed on the right.

In the case of Swirl spreading an element to an elemental slime (e.g. a Pyro-infused swirl reaction hitting an Electro slime), the resulting damage scales based off the level and elemental mastery of the slime, not the Anemo character, though the swirl damage itself gets its scaling from the Anemo character.

Summary of element order application
Reaction	Element Order (1st ← 2nd)	Effect
Melt	←	Damage considers additional multiplier of 2 along with additional multiplier from elemental mastery.
Melt	←	Damage considers additional multiplier of 1.5 along with additional multiplier from elemental mastery.
Vaporize	←	Damage considers additional multiplier of 1.5 along with additional multiplier from elemental mastery.
Vaporize	←	Damage considers additional multiplier of 2 along with additional multiplier from elemental mastery.

Talents

Some talents have special effects when an Elemental Reaction is triggered. 4 Talents match the category selection:

Character	Name	Description	Type
Fischl Fischl	Undone Be Thy Sinful Hex Undone Be Thy Sinful Hex	If your active character triggers an Electro-related Elemental Reaction when Oz is on the field, the opponent shall be stricken with Thundering Retribution, dealing Electro DMG equal to 80% of Fischl's ATK.	4th Ascension Passive
Kaedehara Kazuha Kaedehara Kazuha	Poetics of Fuubutsu Poetics of Fuubutsu	Upon triggering a Swirl reaction, Kaedehara Kazuha will grant all party members a 0.04% Elemental DMG Bonus to the element absorbed by Swirl for every point of Elemental Mastery he has for 8s. Bonuses for different elements obtained through this method can co-exist.	4th Ascension Passive
Qiqi Qiqi	Life-Prolonging Methods Life-Prolonging Methods	When a character under the effects of Adeptus Art: Herald of Frost triggers an Elemental Reaction, their Incoming Healing Bonus is increased by 20% for 8s.	1st Ascension Passive
Sucrose Sucrose	Catalyst Conversion Catalyst Conversion	When Sucrose triggers a Swirl effect, all characters in the party with the matching element (excluding Sucrose) have their Elemental Mastery increased by 50 for 8s.	1st Ascension Passive