Improved Overrun
From Compendium of Worldly Lore
Needs review
Source: Player's Handbook
Description: You are skilled at knocking down opponents.
Prerequisites: STR 13, Power Attack
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.
Special
A fighter may select Improved Overrun as one of his fighter bonus feats.
Normal
Without this feat, the target of an overrun can choose to avoid you or to block you.