Improved Overrun [General]
Prerequisites: Str 13, Power Attack.
Benefit: When you attempt to overrun an opponent, the target may not choose to avoid you. You also gain a +4 bonus on your Strength check to knock down your opponent.
Normal: Without this feat, the target of an overrun can choose to avoid you or to block you.
Special: A fighter may select Improved Overrun as one of his fighter bonus feats.
Source: SRD 3.5 Feats