After World War II, the US Airborne units sought ways to improve their anti-tank firepower to defend against enemy armour attack after an airdrop. As the design must be lightweight for airborne purposes, it must contain the most firepower possible on a mobile platform. This translated into the installment of a 90 mm M54 gun onto a small tracked chassis. This small vehicle was accepted for service in 1958 as the M56, or by its nickname "Scorpion". 150 units would be produced by Cadillac Motor Division and saw combat service in the Vietnam War.

Introduced in Update 1.63 "Desert Hunters", the M56 is one of the lightest tank destroyer in the game. Despite that, it contains a very powerful punch with a 90 mm M54 gun with the standard complement of 90 mm ammunition that can be seen on the 90 mm equipped medium tanks. This includes the lethal HEAT-FS round, which can penetrate up to 320 mm of armour, more than enough against most of the M56's enemies. Being lightweight also provides mobility benefits, as the engine is more than enough to propel the M56 quickly, allowing it to weave through rough terrain to get into optimum position and hide with its low profile to wait for the right moment to strike. However, the exposed crew and the bare armour means even a light spray of machine guns can be enough to knock out or outright destroy the vehicle.