Powerful shot
rogue attack 13
ranged weapon
Requirement: wielding a crossbow, a light thrown weapon, or a sling.
Target: one creature
Attack: Dexterity vs. AC
Hit: "3[W] + Dexterity modifier damage, you push the target 1 square, and the target is slowed until the end of your next turn."[MP:80]
Powerful shot is an encounter power available to rogues at 13th level.