Pistol Mastery
Pistol Mastery is a Pirate secondary attribute, meaning that any character with Pirate as their primary or secondary profession can put points into this attribute.
Guild Wars Description
"No inherent effect. Pistol Mastery increases the damage you do with pistols and your chance to inflict a critical hit when using a pistol. Many skills, especially pistol attack skills, become more effective with higher Pistol Mastery."
General Description
Pistol Mastery directly relates to the weapon 'pistol' and skills required by an pistol.
Pistol Mastery is a requirement for meeting an pistol's max damage.
The Pistol Mastery attribute increases the damage, adrenaline gain and the ability to extend the duration of a variety of conditions on a enemy through pistol mastery skills.
As well as increasing the critical rate, the pistol mastery attribute will add hidden damage by changing the Effective Damage Level (EffDL) if certain conditions are meet. For further information about this, see Damage Level.