The Thompson is an American submachine gun, invented by John T. Thompson in 1919, that became infamous during the Prohibition era. It was a common sight in the media of the time, being used by both law enforcement officers and criminals. The Thompson was also known informally as: the "Tommy Gun", "Trench Broom", "Trench Sweeper", "Chicago Typewriter", "Chicago Piano", "Chicago Style", "Chicago Organ Grinder", and "The Chopper".
The Thompson was favored by soldiers, criminals, police and civilians alike for its ergonomics, compactness, large .45 ACP cartridge, reliability, and high volume of automatic fire. It has since gained popularity among civilian collectors for its historical significance.
In Project Reality, the Thompson appears as a weapon for officers of the United States Army (1940). Its high rate of fire, paired with low recoil, 2-shot-kill ability, and a 30-round magazine makes it a prime choice for a soldier's main weapon.
- Some players have found the Thompson so useful, that players have used the commander slot to simply obtain an officer kit.
- The Thompson uses the 7.62x39mm projectile as a placeholder, enabling it to have a high damage, moderate range, while having the lower recoil of a .45 ACP round.