Damage
This article explains the mechanics of damage calculation in Arknights.
Overview
All damage are calculated to the exact value, accounting the decimals, but if the damage is to be shown in-game (see Trivia) or in the menu, the value is rounded up (e.g. 99.9 is shown as 100).
By default, the damage dealt by attacks or use of skills that scales with ATK are calculated by the following formula:
a = [(b × (1 + x1)) + x2] × y
Where:
- a represents the final damage.
- b represents the original ATK.
- x1 represents the sum of all base ATK buffs.
- x2 represents the value of ATK Inspiration.
- y represents the final ATK multiplier.
However, the exact damage dealt is determined by their type (Physical, Arts, True, and Elemental) and interaction with the target's defenses (DEF, RES, and E-RES). Regardless of the type, the final amount of damage dealt will always be at least 5% of the attacker's ATK before independent percentage-based modifiers are factored in.
Types
Technically HP recovery or healing is considered as a damage type, but not listed here due to its simplicity. It is worth noting however, that the healing "damage type" encompasses any form of HP restoration which shows the value as green numbers above them, such as those of Medics, and cannot be "inflicted" on targets with full HP.
Sources
Damages are also divided by the source which inflicted them.
| Source | Information | Example |
|---|---|---|
| Attack | All damage dealt by the unit's normal attacks, including if their attack is modified through certain skills. | Ch'en the Holungday's "Holiday Storm", Młynar's Unbrilliant Glory, Surtr's Twilight |
| Additional | All damage added to the unit's normal attacks. The additional damage is usually inflicted before the attack hits. | Ceobe's Thresher, Mech-Accord Caster's Drone |
| Skill | All damage dealt through the unit's skills, including its associated effects. This also includes effects provided by a unit that can be inflicted by others. | Archetto's Pursuing Arrows, Sesa's Delayed Concussive Parts |
| Debuff | All damage applied through a debuff. | Thorns' Nerve Corrosion, distance-based damage effects |
| Independent | All damage that is not tied to the unit which inflicts them, thus units defeated through independent damage will not be considered defeated by the source. | Blue Poison's Neurotoxin, Ethan's Fancy Maneuvers, W's D12 |
Lethal
A lethal or fatal damage is defined as any damage that exceeds the target's current HP, or in other words, would reduce the target's HP to 0. Lethal damage will trigger certain effects depending on the calculation which will be explained below; for instance, Dreadnought Guards' DRE-Y Operator Module will reduce the fatal damage they receive to 0 and fully restores their HP once per deployment.
Interestingly, Physical damage dealt will be fatal if the value is equal to or greater than the target's current HP, while Arts damage dealt will only be fatal if the value is greater than the target's current HP. Therefore, it is possible for a unit to survive with 0 HP when they take Arts damage exactly equal to the current HP.
The following are the possible lethal damage calculations:
| Calculation | Information | Example |
|---|---|---|
OnTakeDamage
|
If the incoming damage exceeds the current HP even if it is non-lethal, the damage becomes lethal. | Horn's Bloodbath |
DoApplyModifier
|
If the incoming damage is non-lethal, it will leave the target with at least 1 HP, otherwise the damage becomes lethal. | Hemopoetic Inhibition |
SetHpInternal
|
If the difference between the incoming damage and the target's current HP is 0 or lower, the damage becomes non-lethal and will never reduce the target's HP to below 1. | Surtr's Remnant Ash |
Tips
As a general rule, enemies with high DEF usually have low RES and vice-versa, but certain elite enemies and most bosses have identical levels of DEF and RES. Against such enemies, the following should be used:
- Sources of True damage and ways to ignore DEF/RES.
- Extremely high Arts damage (at least 1000 in a single hit). For instance, when an Operator with 500 ATK hits enemies with an A rating on their DEF and RES (~800 and ~50, respectively), the enemy will take only ~25 physical damage but takes ~250 Arts damage (10 times the physical damage they would have taken).
- Conversely, if the Operator deals high enough physical damage, for example 1200, the enemy would take 400 physical damage, making it more effective than Arts at extremely high levels. However, such Operators are few and far in between, leaving Arts damage as the most reliable option.
- In general, physical damage has a higher damage ceiling, while Arts damage has higher consistent damage.
- DEF and/or RES debuffs.
- Damage amplifications (only if the initial hit dealt a non-negligible amount of damage).
Trivia
- If the final damage (after factoring in skill, talents, and other effects) dealt by an attack is at least 50% higher than the original damage (i.e. if only visible ATK and DEF/RES were used for the calculation), the damage dealt will be displayed as a red number above the target. This includes but is not limited to the following scenarios:
- On-hit ATK multipliers.
- Damage amplification, such as Fragile.
- Abilities that increase the 5% minimum damage threshold (like Projekt Red's Chill or Aciddrop's Slideshot Style).
- Attacks that ignore a certain amount of DEF or RES on hit.
- Attacks that hit an invulnerable target (such as an attack fired at a target that was put to Sleep before it hit) will appear as dealing 0 damage.
- The damage indicator (see above) is capped at 10 digits (i.e. 9,999,999,999), although this normally cannot be achieved.