Critical hit

Occurrence
Each weapon attack has an independent chance of dealing a critical hit. A higher weapon attribute increases this chance. Attacker and target levels are also factors. A few skills can cause or negate critical hits, as specified in their description. If you strike an opponent who is fleeing from you, you will always score a critical hit.

Effects
Whenever a critical hit occurs, the damage done is equal to the maximum damage of the weapon multiplied by approximately &radic;2, the equivalent of striking for maximum damage with a weapon attribute 4 higher than actually possessed. Non-critical hits are a random value chosen between the minimum and maximum damage values of the weapon.

According to empirical research done by game players, it appears that each weapon attribute point increases the chance to critical hit by ~1.44%. The recorded critical hit rates with a 12 and a 16 weapon mastery were 15% and 23% respectively, while the best linear fit suggests approximately 17.5% and 23.5% (R^2=0.953). Every point in the Critical Strikes attribute increases the critical hit rate by 1%.

Ensign generated a list based on a study of over 8000 hits, with a result of ~1.3% per point in Weapon Mastery, or more precisely 0.0133x + 0.01. This table shows his results:

From these observations, a linear progression table can be approximated:

Related skills
These skills guarantee critical hits when they hit:
 * Critical Strike
 * Malicious Strike (if it hits a foe with a Condition)
 * Decapitate
 * Wild Blow

These skills involve critical hits in other ways:
 * Critical Defenses provides a chance to block attacks, refreshes when you land a critical hit.
 * Critical Eye raises critical hit chance and you gain +1 energy for every critical hit you make.
 * Dark Apostasy removes one Enchantment from your target on critical hit.
 * Sharpen Daggers causes bleeding on critical hits.
 * Siphon Strength raises critical hit chance against targeted foe.
 * Way of Perfection heals when you make a critical hit.
 * Way of the Assassin raises critical hit chance while you are enchanted.
 * Stone Sheath prevents the foe and adjacent foes from making critical hits.
 * Dulled Weapon prevents the foe and adjacent foes from making critical hits.
 * "Find Their Weakness!" causes a party member to inflict a Deep Wound with their next critical hit.
 * "Go for the Eyes!" raises critical hit chance by allies within earshot.
 * Vicious Attack will apply a Deep Wound if a critical hit is achieved.
 * Balanced Stance prevents extra damage from critical hits.
 * Primal Rage raises critical hit chance.
 * Disrupting Accuracy critical hit arrows interrupt the target

The Assassin's Critical Strikes attribute improves the critical hit chance with any weapon. This stacks with ranks in attributes such as Swordsmanship, Marksmanship, and Dagger Mastery, which affect critical hits as mentioned above.