A Curb Stomp is a type of Execution in Gears of War, Gears of War 2, and Gears of War 3 that kills a Downed enemy. The Curb Stomp is iconic of the Gears of War franchise, which is famous for its violence and detail of blood and gore.
A Curb Stomp occurs when a player near a Downed enemy presses the "X" button, or by tapping the "Y" button for Gears of War 3. Players performing the Curb Stomp are vulnerable to damage. In Gears of War, a character performing a Curb Stomp would raise his foot and quickly bring it down, smashing the enemy's head into the ground and killing the enemy. In Gears of War 2 and Gears of War 3, the character would use his legs to flip an enemy on his back and then stomp on the enemy's head. Additionally, the point of view of the character performing the Curb Stomp in both games will sometimes shift outside of the over-the-shoulder view to focus more on the performance of the Curb Stomp, creating a cinematic perspective.
Players and AI (both allies and enemies) are able to Curb Stomp an enemy in the campaign and multiplayer. A Curb Stomp cannot be used on an enemy who is not downed, nor can it be used to down an enemy.
During Gears of War, when a player downs an enemy in, you can do a Curb Stomp (X). During this execution you can use your right stick to spin your character in a 360 motion in any direction of choice.