The Strv 81 was the Swedish designation for the Centurion Mk 3. Sweden acquired a batch of 80 Centurion Mk 3 in 1953, and another batch of 160 in 1955 with a few modifications from the later Mk 5 version like a new barrel with bore evacuator. The Strv 81 would serve in the Swedish army from 1953 until the 2000s as the backbone of the Swedish armoured forces alongside the Strv 103. They had an extensive service and would be modernized a few times throughout their service to meet standards as time progressed, becoming the Strv 102 and 104, but would eventually be replaced by the more modern Strv 121.

Introduced in Update 1.97 "Viking Fury", the Strv 81 represents a Swedish-camouflaged Centurion Mk 3. Its gameplay is very similar to that of modern main battle tanks. Players never have to worry about opponents appearing around corners and stopping to take aim with the two-plane fully automatic stabilization system. Even with aggressive manoeuvring, the gun sights are fully stabilized, ensuring that the player always fires first upon spotting an enemy. The introduction of the 84 mm QF 20-pounder tank gun, which can penetrate up to 384 mm of armour at point-blank range with armour-piercing discarding sabot (APDS) ammunition, significantly improves firepower. This basically allows the player to engage the opponent's heavy tanks on their own terms, serving as a true ancestor to the main battle tank doctrine.