The BM-31, also known as “Andryusha” in some sources, was a Soviet multiple rocket launcher system developed by the Reactive Scientific Research Institute in 1942. The BM-31 was a further development of the famous BM-13 “Katyusha” rocket launcher system, utilising massive 300 mm rockets. Due to the huge warhead size, the BM-31 was initially designed as a static launcher.

As the Red Army went on to conduct offensives in the latter half of the war, the need for mobile siege artillery to destroy German fortifications arose; the SKB Kompressor plant submitted a design for a mobile version of the BM-31 in March 1944, later known as the BM-31-12. This mobile version was similar to its “little sister”, the BM-13N, in that it used the lend-lease Studebaker US6 truck as its chassis due to its reliability and mobility. When it entered service in June 1944, the BM-31-12 proved its worth by providing a much-needed firepower to break German defences. By the end of the war, around 1,800 BM-31-12s had been built before they were eventually phased out after the war by a variant based on the domestic ZIS-151 truck.

The BM-31-12 was introduced during Update “Sky Guardians” as a reward for the 2023 Legend of Victory event. Andryusha is an artillery piece, belonging more in an artillery formation than in a tank battle. Much like its “little sister”, the BM-13N “Katyusha”, Andryusha is based on the same truck chassis and therefore is extremely vulnerable to incoming fire; this is not helped by the fact that it has only two crew members, meaning even a grazing hit from machine guns can knock it out. However, the BM-31 features an ace up its sleeve in the form of twelve 300 mm rockets, with massive warheads of nearly 29 kg of explosives. This allows the BM-31 to destroy any vehicle in a direct hit. Still, due to its inability to fire directly forward, the BM-31 will be forced to stay at distance to land a hit on targets.