Knock Heads
You push foes into each other with disorienting, painful force.
Preqrequisite
Improved Combat Maneuver (bull rush).
Benefit
When you succeed at a bull rush combat maneuver and push the target into another creature’s space, the target stops in the previous square as normal. However, both the target and the other creature take damage equal to half your character level plus your Strength modifier and gain the off-target condition until the beginning of your next turn. The second creature can reduce the damage by half and negate the off-target condition with a successful Reflex save (DC = 10 + 1/2 your level + your Strength modifier)
Source
Ports of Call pg. 43
Dragonscript
ID
c7f83ee1831a4df0e6364e70
Preqrequisite
condition character.feats contains '9400f755a09fde832ae236cc';