Attack

ChargedAttacks
Each weapon has a primary attack(default on left mouse button) and charged attack(default on right mouse button).

To perform a charged attack hold the charged attack button and press the primary attack button.

Some ranged weapons have several tiers of charged attack. Going to higher tiers can be done by holding the charged attack longer(before pressing the primary attack to unleash the charged attack)

Holding charged attack on melee weapons will perform a Block

Critical Hit
Each attack has a critical hit chance. Achieving a critical hit will cause extra damage.

By default, all characters have a base critical hit chance of 5%. Factors that affect critical hit chance are: the type of Weapon, the bonus gained from the "Crit Chance" item Property, certain Passive Abilities, as well as Career Talents.

Kerillian's dual-weapons, such as Dual Daggers, Dual Swords, and Sword and Dagger have an extra 10% critical hit chance on light attacks as well as push attacks, but do not have increased critical chance on charged attacks.

Bardin's Crossbow and Saltzpyre's Crossbow give 10% increased critical hit chance when aimed down (holding RMB/left trigger).

The bonus damage depends on the weapon and the bonus gained from the "Crit Power" item property.