A Submachine Gun (SMG) is a magazine-fed, automatic/semi-automatic carbine designed to handle like a pistol/small assault rifle with the firepower of a light assault rifle. Whilst being used by humans long before 2184 CE, the SMG first entered galactic circulation following the Battle of the Citadel and the switch to ammunition-fed weapons, brought about a sudden exposure to human weapons technology that occurred due to the heroic actions of the Fifth Fleet that led to the defeat of Sovereign and the geth in 2183 CE.