Critical Hit Chance, Critical Damage Bonus, and the Crit Transition in Path of Exile 2

Critical hits are one of the most misread systems in Path of Exile 2 because several distinct numbers share similar names. Getting the vocabulary right is the first step to building around crit correctly.

Base Crit Chance is the starting probability from the source of the hit. For attacks this comes from the weapon's base critical strike chance; for spells it comes from the skill's own base. It is a property of the source, not something you stack directly.

Flat Crit Chance is any additive bonus to your crit chance that is not a percentage. These flat values are added to the base before Increased modifiers are applied.

Increased Crit Chance is the sum of all your '+% to Critical Hit Chance' modifiers. Like other Increased modifiers, they add together into one multiplier. This is separate from flat crit chance and must not be confused with it.

Critical Damage Bonus is the extra damage applied when a hit crits. It is expressed as a bonus (for example a flat +X% on top of the normal hit) rather than as a single 'multiplier' number. All sources of Critical Damage Bonus add together.

• Base Crit Chance: where the crit roll starts (weapon for attacks, skill for spells).
• Flat Crit Chance: additive points added to the base, applied before Increased.
• Increased Crit Chance: all +% crit chance modifiers summed into one multiplier.
• Critical Damage Bonus: extra damage on a crit, all sources add together.
• Do not mix up flat crit chance with Increased crit chance — they occupy different steps of the calculation.

A critical hit is decided by a single random roll against your Crit Chance for each 'crit check'. The number of crit checks depends on how the skill deals damage, and this is where many players over-simplify.

For a normal single Hit, one crit check is rolled. For a skill that hits multiple times (multi-hit), each separate hit performs its own crit check, so some hits can crit while others do not. For channeled skills, each damage tick is generally its own check. For damage over time, crit interaction follows the current Path of Exile 2 rules for ailments and DoT, which differ from a normal hit and should be sourced per the current version.

Critically, the hit must land first. For attacks, the Accuracy versus Evasion roll happens before the crit roll: if the attack is evaded, it never becomes a crit. A crit roll can therefore be 'wasted' on a hit that misses. Lucky and Unlucky modifiers, where they apply, affect how the crit roll is performed; describe their behavior from the current in-game tooltip.

• One crit check per Hit, rolled against your Crit Chance.
• Multi-hit skills roll crit separately for each hit.
• Channeled skills usually roll per damage tick.
• DoT and ailments follow their own current crit rules — source them.
• An evaded attack cannot crit; accuracy gates crit relevance.

The accumulation structure is the same across versions, even when exact coefficients change. Final Crit Chance is built from the base plus any flat crit chance, and then all Increased Crit Chance modifiers multiply that sum.

In formula terms: Final Crit Chance = (Base Crit Chance + Flat Crit Chance) x (1 + sum of Increased Crit Chance%). Critical Damage Bonus is handled separately: when a hit crits, it deals the normal hit damage plus the summed Critical Damage Bonus. Both systems add their same-category bonuses together; different categories and any More multipliers then multiply.

The numbers below are teaching examples with assumed values and are pending PC verification. They illustrate the structure, not the exact live coefficients.

• Start from Base Crit Chance (weapon for attacks, skill for spells).
• Add Flat Crit Chance on top of the base.
• Multiply that sum by (1 + total Increased Crit Chance%).
• On a crit, add summed Critical Damage Bonus to the hit damage.
• Increased bonuses of the same category add; separate categories and More multipliers multiply.

Crit chance is meaningless on a hit that never lands. For attack skills, the Accuracy rating is rolled against the enemy's Evasion before the crit roll. If you miss, the crit roll is never performed, so the attack deals no damage at all.

This means stacking Crit Chance without enough Accuracy is a trap. A high Crit Chance paired with a low Hit Chance produces few actual crits, because most attacks are evaded before they can crit. Spell skills that cannot miss by evasion still must connect with the target, so positioning and projectile behavior still matter.

When evaluating a crit transition, always pair your Crit Chance with your real Hit Chance. A lower Crit Chance that actually lands outperforms a higher Crit Chance that is constantly evaded.

• Attacks roll Accuracy vs Evasion before the crit roll.
• An evaded hit deals no damage and cannot crit.
• High Crit Chance with low Hit Chance wastes most rolls.
• Pair Crit Chance with real Hit Chance when planning the transition.