A boxer gains skill through training. Boxers guard themselves and then attack with precision strikes. They often take their time and find weakness in a foe's fighting ability, and tend to drag a fight out on purpose so that their foes get tired. Sometimes boxers display their skills socially fighting for sport in rings, cages, or arenas. Boxers tend to train in schools with other boxer but some gain skill by themselves working to learn where and when to hit their foes.
Guard (Ex): Starting at 5th level a boxer's guard is advanced enough to turn aside the most powerful of blows. Treat the boxer as if he has moderate fortification. A boxer retains this ability even if flat-footed.
Pick and Choose (Ex): Starting at 10th level a boxer's ability to watch for openings proves to be his most powerful ability. As a standard action a boxer can make one attack, that if it hits it counts as a critical. You do not need to confirm the critical hit. This ability can not be used in the first round of melee combat with a foe.
Stamina (Ex): Starting at 16th level a boxer's control over the fight reaches a point where his foes find it tiring to deal with him. At the end of a foe's third consecutive round of melee combat with the boxer and every round after, it must make a Fortitude save (DC = 10 + 1/2 the pugilist's level + Constitution modifier) or become fatigued. If the target is fatigued already, or fails a second save it then becomes exhausted.
Corner (Ex): Starting at 20th level a boxer's ability to control his foes reaches its peak. If an adjacent foe takes a move action he provokes an attack of opportunity. If the boxer successfully damages the foe with this attack, the enemy cannot complete his action. This does not stop his foe from using another move attempt, but doing so will provoke another attack of opportunity.