The IS-1 (’45) is a Soviet heavy tank, representing a deep redesign and modernization of the KV-1/KV-1S series. While retaining some structural elements of its predecessors, it received reinforced armor and a new main gun. The vehicle performs well as a breakthrough tank: its strong frontal armor is capable of withstanding hits from anti-tank weapons.

In-game, the tank comes equipped with a camouflage net and white identification stripes on the turret — a historical camouflage intended to prevent friendly fire from allied forces.

Its main armament consists of an 85 mm D-5T gun with 59 rounds of ammunition, supported by a coaxial 7.62 mm DT machine gun with 2,520 rounds.