Seizing an opening, you shove a distracted enemy and send it sprawling, just as an ally strikes.

Encounter   ✦     Martial
Standard Action      Melee 1

Target: One creature granting combat advantage to you

Attack: Highest ability modifier + 3 vs. Reflex
    Level 11: Highest ability modifier + 5
    Level 21: Highest ability modifier + 7

Hit: The target falls prone.

Effect: One ally of yours adjacent to the target can make a melee basic attack against the target as a free action.

Published in The Book of Vile Darkness, page(s) 1-14.