You know how to slam into a foe in a way that is both damaging and effective at relocating him.
Benefit: You can charge into a foe and use your body to damage him, while simultaneously pushing him backwards. When you make a Bull Rush, you also make a normal melee attack roll. (This is considered a charge.) If your attack roll succeeds, you deal melee damage. The damage is 1d3 if you are unarmored, 1d4 if in light armor, 1d6 in medium armor, and 1d8 in heavy armor. You add 150% of your Strength bonus to this damage.
Adventurer’s Handbook: Genius Guide Volume 1