There is no single critical-strike formula shared by all games. In a simple system where an attack either crits or does not, a critical hit deals B × M, while expected damage over many attacks is B × [1 + p(M − 1)]. Here, B is damage before the critical multiplier, M is the total critical-hit multiplier, and p is critical chance written as a decimal.
How to calculate damage from one critical hit
For a single hit, multiply the damage that is eligible to crit by the game’s total critical-hit multiplier:
Critical-hit damage = B × M
- B is the applicable damage before the critical multiplier.
- M is the total multiplier expressed as a decimal: for example, 180% is 1.8.
If an eligible hit would deal 100 damage before the multiplier and the game gives it a 180% critical multiplier, the critical hit deals 180 damage before any other game-specific adjustments. This calculation does not establish whether a particular attack or damage type can crit, or how the game orders defenses, buffs, caps, and rounding.
How critical chance changes average damage
To estimate damage across many attacks in a simple binary system, include the probability that each attack crits:
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Expected damage per attack = B × [(1 − p) + pM] = B × [1 + p(M − 1)]
Here, p is critical chance as a decimal. The first expression weights normal hits by their chance, 1 − p, and critical hits by their chance, p. The equivalent second expression shows the average uplift over the non-critical baseline: p(M − 1).
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For example, with a 25% critical chance (p = 0.25) and a 180% multiplier (M = 1.8), the expected damage is B × 1.2: 20% more than the same baseline damage without critical hits. This is an average over repeated attacks, not the damage of any one critical hit.
Why the formula changes from game to game
The basic calculation is useful for understanding the relationship between damage, chance, and multiplier, but it is not a substitute for a game’s full rules. Games may calculate critical chance from several stats, apply different multipliers to different attacks, or exclude some damage types.
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1Scan for outdated or missing drivers - takes under a minute2Repair Windows errors before they cause bigger problems3Fix the driver behind crashes, sound loss and screen glitches- Guild Wars 2: The Guild Wars 2 Wiki critical-hit reference describes critical hits as multiplying strike damage, lists a default of 150% damage, and says condition damage cannot crit. Its example gives 20% more average damage for a 25% chance and 180% multiplier. These are game-specific figures; check current in-game rules before relying on them.
- Path of Exile: The Path of Exile critical-strike reference describes critical damage using a base critical-strike multiplier plus additional critical-strike multiplier, and treats critical chance as a separate calculation involving base, additional, increased, and more chance. The simple expected-value equation does not replace those stat calculations.
- League of Legends: The League of Legends critical-strike reference reports 175% default critical damage for basic attacks and a separate formula for expected repeated-attack damage. That figure should not be generalized to every attack or ability.
- Teamfight Tactics: The Teamfight Tactics critical-strike reference describes a distinct system, including 25% base critical chance and 40% base bonus critical damage. The referenced result is older, so treat these values as an illustration of how systems differ, not as confirmed current rules.
What to check before comparing critical builds
Identify the game and its version first, then compare the parts of its rules that determine actual damage:
- Critical chance and how the game derives it from stats.
- The total critical multiplier, including base and added critical damage.
- Which attacks and damage types are eligible to crit.
- Other modifiers, damage caps, defenses, and the order in which the game applies them.
Without the game and version, the only reliable general answer is the simplified model above. For an exact result, use that game’s current rules for the relevant attack and damage type.
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