Critical Hits increase an attack's damage by 25%, or by 50% if the enemy is suffering from Topple or Daze. Fiora's "Ultimate Strike" skill increases the damage of critical attacks by another 20%. In addition, landing a Critical Hit fills the Party Gauge by 10% of one bar.
Critical Rate is the probability that an attack will score a Critical Hit. The base rate is 5% plus the critical rate of the equipped weapon. It may be further raised or lowered by: