Weapon Training | Pathfinder Wrath of the Righteous Wiki

Starting at 5th level, a fighter can select one group of weapons. Whenever he attacks with a weapon from this group, he gains a +1 bonus on attack and damage rolls.
Every four levels thereafter (9th, 13th, and 17th), a fighter becomes further trained in another group of weapons. He gains a +1 bonus on attack and damage rolls when using a weapon from this group. In addition, the bonuses granted by previous weapon groups increase by +1 each. For example, when a fighter reaches 9th level, he receives a +1 bonus on attack and damage rolls with one weapon group and a +2 bonus on attack and damage rolls with the weapon group selected at 5th level. Bonuses granted from overlapping groups do not stack. Take the highest bonus granted for a weapon if it resides in two or more groups.
A fighter also adds this bonus to any combat maneuver checks made with weapons from his group. This bonus also applies to the fighter's Combat Maneuver Defense when defending against disarm attempts made against weapons from this group.