Tripping Staff

Combat

You can make a trip attack with your quarterstaff.

Prerequisite: Int 13, Combat Expertise, Improved Trip, Weapon Focus (quarterstaff), base attack bonus +6.

Benefit: You treat quarterstaves as if they had the trip special feature.

Special: If you are a magus with the staff magus archetype, you can use spellstrike on any trip combat maneuver you make with the staff.

Source: Ultimate Magic