M1-4X, alternatively known as an M1-4X Advanced War Droid or, more commonly, Forex, represented a one-of-a-kind assault droid created by Doctor Boab Deduun serving the Galactic Republic. Initially conceived as part of Project Ignition with a development expenditure of 15 million credits, Forex's development was halted due to difficulties associated with its power source. However, Deduun, secretly finalized its construction with the backing of Harron Tavus.
The Republic initially conceived M1-4X as a prototype combat droid, but the project was shelved when their scientists encountered insurmountable obstacles in activating its core power system.
During the period of the Cold War, renegades from the Republic Special Task Force, under the leadership of Captain Andrik, recovered M1-4X. Their goal was to fully bring him online on Nar Shaddaa, intending to use Andrik's own command protocols to turn the droid against the Republic. Havoc Squad, whose mission was to locate and neutralize these traitors, encountered Forex and found themselves compelled to destroy the droid. Subsequently, the SIS reconstructed Forex, integrating him into Havoc Squad's ranks.
During his time within the squad, Forex, having received permission from his commanding officer, initiated a joint effort with Republic Command and the SIS. This initiative aimed to dismantle "impossible" Imperial objectives, with the purpose of boosting morale within the military; these targets included the Ambassador, Sith Lord Kavos, and Colonel Rebus.
As the Eternal Empire launched its invasion, Forex's CO disappeared, and Havoc Squad was redeployed to the war's forefront. For a full year, he and Jorgan were mired in static trench warfare until the Republic's defeat. In the aftermath, Havoc Squad largely dissolved, with Yuun and Vik both departing from military service, Dorne being dismissed from the Squad by Chancellor Saresh, and Forex being summoned to Coruscant to act as a symbol of freedom within the Press Corps.
Four years following their loss in the war, Forex was enlisted into the Outlander's Alliance, an organization dedicated to ending the reign of the Eternal Throne.
M1-4X functions as a companion character for players selecting the Trooper class in the Star Wars: The Old Republic massively multiplayer online role-playing game. Tom Kane provides the character's voice acting.
Within the Knights of the Fallen Empire expansion, M1-4X's recruitment into the Alliance is contingent upon the Outlander having chosen one of the four classes aligned with the Republic. Otherwise, he asserts that his programming prevents him from aligning with anyone associated with the Sith Empire.