Editing Ogre:CharacterCodex:Combat:Maneuver (section)

====Bull Rush====
When you make a bull rush, you attempt to push an opponent straight back instead of damaging him.

First, you move into the defender’s space. Doing this provokes an attack of opportunity from each opponent that threatens you, including the defender. For any attack of opportunity made by anyone other than the defender against you during a bull rush, you have the benefit of a half-cover from your opponent. If the defender’s attack of opportunity deals any damage, your bull rush attempt suffer a penalty equal to the damage you have received.

Second, you make a Move Attack against the Stability of the opponent. If you succeed, you push him back 5 feet. If you wish, you can move with the defender. If you fail, you move 5 feet straight back to where you were before you moved into his space. If that space is occupied, you fall prone in that space.