Your shout draws the enemy's attention so that your allies can maneuver around the foe, letting them get in close or get away.

Encounter   ✦     Arcane, Implement, Thunder
Standard Action      Ranged 10

Target: One creature

Attack: Charisma vs. Will

Hit: 2d8 + Charisma modifier thunder damage, and the target takes a -5 penalty to opportunity attack rolls until the end of your next turn.

  Virtue of Cunning: The penalty to opportunity attack rolls equals 4 + your Intelligence modifier.

Published in Player's Handbook 2, page(s) 72.