Improved Trip [General]
You are trained not only in tripping opponents safely but also in following through with an attack
Prerequisites:Int 13 , Combat Expertise.
Benefit: You do not provoke an attack of opportunity when you attempt to trip an opponent while you are unarmed. You also gain a +4 bonus on your Strength check to trip your opponent.
If you trip an opponent in melee combat, you immediately get a melee attack against that opponent as if you hadn't used your attack for the trip attack for the trip attempt.
Normal: Without this feat, you provoke an attack of opportunity when you attempt to trip an opponent while you are unarmed, see trip, players handbook page 158.
Special: A fighter may select Improved Trip as one of his fighter bonus feats (see page 38).
At 6th level, a monk may select improved trip as a bonus feat, even if she does not have the prerequisites.
Source: Player's Handbook