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Toppling slash
rogue attack 13

Requirement: wielding a light blade

Target: one creature

Attack: Dexterity vs. AC

Hit: "2[W] + Dexterity modifier damage, and you push the target 1 square and knock it prone."
Brutal Scoundrel: The attack deals extra damage equal to your Strength modifier, and you push the target 1 extra square.[MP:81]

Toppling slash is an encounter power available to rogues at 13th level.