The Retro Lancer, previously known as the Pendulum Wars Lancer Assault Rifle, was used during the Pedulum Wars as the COG army's primary weapon. After Emergence Day, the Retro Lancer saw to be ineffective against the invading Locust Horde and was replaced by the Lancer Assault Rifle as the go-to-rifle for all COG soldiers. After the events of Gears of War 2, the Retro Lancer began popping up again, due to shortages of other weaponry.
The rifle is fitted with a bayonet on the front of it, which in conjunction with a little running build up, will impale any enemy that comes in contact with it. The bayonet is also useful for outright stabbing the enemy, or, slicing their throats as seen in some executions.