The material below is Open Game Content from a 3PP Source
Weapon Focus (Combat)
Choose one type of weapon. You can also choose unarmed strike or grapple (or ray, if you are a spellcaster) as your weapon for the purposes of this feat.
Prerequisites: Proficiency with selected weapon, base attack bonus +1.
Benefit: You gain a +1 bonus on all attack rolls you make using the selected weapon.
Special: You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new type of weapon.
The material below is Open Game Content from the System Reference Document.
WEAPON FOCUS [Combat]
Choose one type of weapon. You can also choose unarmed strike or grapple (or ray, if you are a spellcaster) as your weapon for purposes of this feat.
Prerequisites: Proficiency with selected weapon, base attack bonus +1.
Benefit: You gain a +1 bonus on all attack rolls you make using the selected weapon.
Special: You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new type of weapon.
A fighter may select Weapon Focus as one of his fighter bonus feats. He must have Weapon Focus with a weapon to gain the Weapon Specialization feat for that weapon.