The first M1 Abrams tank originally featured a 105 mm M68A1 gun as part of cost concerns to get the Abrams into service. However, after its acceptance in 1981, the US military began looking into the more powerful 120 mm Rheinmetall smoothbore gun for use in the Abrams. Following a trial period with the M1E1 prototype with the 120 mm M256 gun installed, the vehicle was officially accepted into service in 1984 as the M1A1 Abrams, with production lasting from 1985 to 1993. The M1A1 would set the standard of the modern Abrams design, becoming the most numerous produced base version of the Abrams tank at around 5,000 units manufactured (including retrofits to older M1 and IPM1 into M1A1 standards), and would most notably see combat in the US campaign in the Middle East such as the 1991 Operation Desert Storm and 2003 Operation Iraqi Freedom. The M1A1's ubiquity paved the way for various M1A1 upgrades, foreign sales, as well as the improved M1A2 Abrams.

The M1A1 (shortened to M1A1) has been present in the game since Update 1.87 "Locked On" and gives the highly mobile Abrams platform the deadly 120 mm M256 gun to use against enemy tanks. The round selection is limited to APFSDS and HEAT-FS, the APFSDS rounds allow for a more even fight against opposing tanks, though may still require the M1A1 to aim at weak points against more protected opponents. The composite armour of the M1A1 retains the effective chemical protection and against downtier opponents, the protection against kinetic shells, especially those in uptiers, would force players to rely on the M1A1 mobility to avoid being hit, as well as excellent "soft" protection like the blow-out panels for the turret bustle ammo racks that can help prevent an ammunition cook-off from outright destroying the tank. The M1A1 remains an impressive vehicle for players to use and outpace their opponents with its mobility and destroy them with the 120 mm gun.