The Type-120's predecessor, the type-24, had several flaws that came to light during its time in service. A slow and vulnerable chassis was the main reason for Stalker Inc. to pull the IFV from active service. The type-120a was designed to replace it. Its performance was above expectations. Quick, agile and deadly against infantry and light armour it best suited the role as a quick reaction vehicle. Today, the Type-120 still serves as Stalker Inc.'s main infantry fighting vehicle.
- Lightweight chassis, making it an extremely agile and relatively fast vehicle.
- Due to its weak armament and thin armour, the Type-120 is ill suited for combat against armoured opponents.
After several months of use, the St.Type-120 models -- as well as the St.Type-25a and St.Type35 series -- were recalled for performance enhancements. The St.Type-120a received several upgrades, including an optimised powertrain, adjustments to electronics and stabilisation mechanism, and most notably compartmentalisation of its vulnerable inner components. As a direct result the survivability, as well as all round performance, increased drastically. In addition it received a modernised turret turret with a more powerful 40mm autocannon. All existing Type-120a models received these upgrades and were designated as the Type-120a-2 series.
The type-120b is an anti-armour version of the Type-120a with its 30mm autocannon. It features the same turret and chassis as the Type-120a, but with the main weapon being replaced by a 75mm cannon. Armed with APHE and AP rounds, combined with the Type-120's speed, this vehicle allows for penetrating enemy medium or even heavy tanks from the side or rear when flanked. While the thickness of the armour on the tank is negligible when it comes to tank to tank combat, the low profile combined with heavy sloping of the frontal and side armour add to its survivability.
Like the Type-120a, the Type-120b series was recalled for modifications to the chassis. The Type-120b received performance- and survivability enhancements, but retained its original turret and armament.
The Type-120c is an anti-air modification of the St.Type-120b-2 chassis. Its armament consists of 2 aim-9 missile launchers. While originally intended for air-to-air use, the missiles proved to be equally efficient as a short-range surface-to-air missile. The SAM launcher is remotely controlled from within the vehicle. The chassis remains unaltered.
A light tank destroyer variant, based on the Type-120 chassis. It features a formidable main weapon for its weight class, a 100mm cannon capable of penetrating up to 170mm of RHA steel. The armour is thin, with a maximum of 25mm of frontal armour, but it makes up for that in mobility.