Major Jackson "Jax" Briggs (U.S.A.) is a cybernetically-enhanced soldier who is the leader of the Outer World Investigation Agency (OIA), Earthrealm's Special Forces unit, in the Mortal Kombat fighting game series.
In the Special Forces' chain of command, he is Sonya Blade's direct superior and the catalyzing force of Sonya's impulsiveness. Jax is clear-headed, careful and always keeping a watch on what his men are doing. When the need arises, he is a beast on the battlefield with the attitude and ferocity of a lion. He unscrupulously makes use of the most advanced technology at his disposal to improve both himself and his unit. He is responsible for the crime lord Kano's disfigurement, forcing him to wear a metal plate over a portion of his face.
In the current timeline, Jax perished at the hands of Sindel and was revived as a revenant by Quan Chi, whom he was forced to serve. Although he was eventually freed and brought back to life, his experiences as a revenant left him traumatized, reducing the once fierce warrior to a broken shell of his former self. Sometime afterward, he married a woman named Vera, with whom he sired a child, Jacqui. Jax was opposed to her joining the Special Forces, as he did not want her to experience the same horrors and traumas he had. In Mortal Kombat 11, it is revealed that his wife had died, breaking Jax even further and causing him to become a recluse. This gave Kronika the opportunity to recruit him in her goal of resetting the timeline, promising him the ability to stop Jacqui from joining the Special Forces. Whilst initially working alongside Kronika, he was convinced to return to the side of good by his past self, his daughter, and Raiden, turning upon his ally and joining the fight against her.