You understand how to use the exotic weapons associated with the weapon groups you have mastered
Prerequisite: base attack bonus +1.
Benefit: You gain proficiency with the exotic weapons associated with the weapon groups you already know how to use.
Axes: waraxe (one-handed).
Crossbows: derringer, pistols and rifle.
Cutting Blades: bastard sword (one-handed).
Maces & Flails: war hammer (one-handed), whip.
Piercing Blades: rapier.
Spears: light lance (light), heavy lance (one-handed).
Slings & Thrown Weapons: net.
Normal: You take a -4 penalty when using a weapon with which you are not proficient.