attack of opportunity
Whirling Staff [General]
You keep your staff spinning and whirling around your body as you fight, forcing nearby opponents to keep their distance.
Prerequisite: Weapon Finesse, Weapon Focus (quarterstaff)
Benefit: You may use your Dexterity modifier in place of your Strength modifier when attacking with a quarterstaff. Further, when you fight defensively (Player’s Handbook, page 140) and are wielding a quarterstaff, you may make an attack of opportunity against any opponent that enters your threat range. The limits regarding the number of attacks of opportunity you may make apply as per normal.
Special: A fighter may select Whirling Staff as one of his fighter bonus feats.