Trip

This feat gives the character an ability to perform the trip combat maneuver. It also grants a +2 bonus to CMB when performing this maneuver, and a +2 bonus to CMD when defending against it. You can attempt to trip your opponent in place of a melee attack. If your combat maneuver is successful, the target is knocked prone. If the target has more than two legs, add +2 to the DC of the combat maneuver attack roll for each additional leg it has. Some creatures—such as oozes, creatures without legs, and flying creatures—cannot be tripped.