The SU-122 was a World War II-era Soviet self-propelled assault gun. Mounted on a T-34 medium tank chassis, the main armament consists of a 122 mm M-30S howitzer. After the German Sturmgeschütz III assault guns proved successful, the Soviet High Command became interested in this concept. Compared to conventional tanks, assault guns had certain advantages. Their lack of a turret allowed for a lower production cost. On the same chassis, they could be equipped with bigger and more potent weapons and constructed with a larger fighting compartment. However, unlike conventional tanks, assault guns usually aim by orienting the entire vehicle, making them less effective in close-quarters fighting.

Introduced in the Closed Beta Test for Ground Forces before Update 1.41, the SU-122 is a truly unique vehicle. Its formidable gun is its primary feature, but considering the incredibly long reload time, players need to make every shot matter. It also possesses formidable frontal armour that can withstand most shells at its rank. However, due to its high shell drop, it is also very difficult for it to hit targets from a distance during battles; therefore, a great deal of experience is required to operate this vehicle well.