Choose a type of exotic weapon, such as dire flail or shuriken (see Table: Weapons for a list of exotic weapons). You understand how to use that type of exotic weapon in combat.
Prerequisites: Base attack bonus +1 (plus Str 13 for bastard sword or dwarven waraxe).
Benefit: You make attack rolls with the weapon normally.
Normal: A character who uses a weapon with which he or she is not proficient takes a -4 penalty on attack rolls.
Special: You can gain Exotic Weapon Proficiency multiple times. Each time you take the feat, it applies to a new type of exotic weapon. Proficiency with the bastard sword or the dwarven waraxe has an additional prerequisite of Str 13.
A Fighter may select Exotic Weapon Proficiency as one of his fighter bonus feats.
Source: Player’s Handbook (Page 94)