Precision is combined with Weapon DPS to determine the damage of weapon attacks.
Weapon Damage = Base Weapon Damage Multiplier * (50% Weapon DPS + 100% Precision)
Precision is a primary stat for Damagers.
Precision can be increased using Equipment Mods, Generator Mods and spending Stat Points in Precision.
The Relentless Precision Tactical Mod can temporarily increase Precision.

Other visible stats:

Hidden Stats: