Jamie Madrox's mutant ability was apparent at birth when a duplicate was created upon his being slapped by the doctor. Two weeks later, Jamie's father resigned from the Los Alamos Nuclear Research Center and moved his family to an intentionally isolated farm in Kansas at the suggestion of Professor Charles Xavier. Later, Damien Tryp, of Singularity Investigations, made his own offer to look after Jamie, claiming that Jamie was not in fact a mutant, but a "changeling," a predecessor to mutants whom develop their powers at birth. Jamie's parents, however, refused to give Jamie to Tryp. From a young age, Madrox was given a special suit to wear that would neutralize his mutant power, but before this could be explained to him a freak tornado killed his parents when he was 15, recently revealed to have been caused by Tryp.
Jamie accompanied Xavier to Muir Island where he became a laboratory assistant to mutant researcher Doctor Moira MacTaggart. Madrox's ability proved invaluable to MacTaggart, and he quickly became a regular fixture on Muir. Unfortunately, Madrox also found himself battling against threats such as the alien Eric the Red and the reality-altering mutant Proteus, who possessed one of Madrox's duplicates in order to escape confinement on Muir. Proteus's possession instantly killed the duplicate, and for the first time Madrox felt the severe psychic backlash this caused. After Proteus was defeated, Madrox again declined to join the X-Men, preferring to remain on Muir with Moira and her lover, the X-Man Banshee. Soon after, Banshee's daughter Siryn came to live on Muir, she and Madrox ultimately grew close.
Eventually, one of Madrox's duplicates sought to remain apart from the original and live his own life. To this end, he drugged the original Madrox and joined Moira and Siryn on a trip to the U.S. to search for Sunspot and Warlock, two missing members of the New Mutants. Eventually finding the runaway mutants as members of the Vanisher's teenage gang, the Fallen Angels, the duplicate Madrox and Siryn were persuaded to join by the alien Ariel. During their time with the group, the duplicate Madrox and Siryn engaged in a brief romance. Eventually, the true nature of the Fallen Angels was revealed to be a ruse by aliens from the Coconut Grove dimension who sought to cure their race's stalled evolution by experimenting on mutants. Defeating the aliens, the team returned to Earth, but apparently disbanded soon after. The duplicate and Siryn rejoined Moira at the Xavier Institute to return to Muir; however, the duplicate had no desire to be reabsorbed and so created another duplicate to take his place on the return trip while he secretly remained in the U.S.
Later, the original Madrox was possessed by the psionic entity the Shadow King during the villain's takeover of Muir; after his defeat Madrox joined the government-sponsored X-Factor team. Unknown to Madrox, the duplicate that had joined the Fallen Angels years before had since found a place in the Nasty Boys, a team of super-powered mercenaries employed by geneticist Mister Sinister. With the help of Senator Stephen Shaffran, a.k.a. Ricochet, a mutant with the ability to turn other mutants' powers and fears against them, the duplicate convinced the Nasty Boys, and Madrox himself, that he was the original. Madrox merged with the duplicate, but it was a ruse; he "disassembled" the duplicate from the inside and remained the dominant personality in order to expose Shaffran and stop Sinister.
Among his X-Factor teammates, Madrox formed a close bond with Guido Carosella, a.k.a. Strong Guy. The pair shared an odd sense of humor and often joked around much to team leader Havok's chagrin. A psychiatric analysis by Doctor Leonard Samson ultimately revealed the reason for Madrox's humorous attitude. His living alone for many years as a child created an almost pathological need for attention to ensure he would never be alone again, and he was willing to do virtually anything - whether it be telling jokes, playing gags, or creative use of dupes - to get people to notice him.
Strengths and Weaknesses
Jamie has a pathological need to entertain others, often using humor (and provocation) in any situation. He occasionally experiences a madness where he loses himself in internal dialogue.
His "dupes" tend to manifest various strong personalities. The ones Jamie senses as normal he often sends far away to benefit the collective. For instance, one has graduated from Harvard... twice. One is a priest. One works for SHIELD, one for HYDRA.
Perpetual Student: Has studied Anatomy, Bio-Physics, Botany, Genetics, Immunology, Camoflage, Counterfeit Recognition, Clue Analysis, Criminology, Detective/Espionage, Disguise, Forensics, Interrogation, Law Enforcement, Philogy, Martial Arts (holds, escapes, grappling), Emergency Medicine, Surgery, Performer/Actor, Trivia:Movies (absolutely OBSESSED with movies), Guns (but not a Marksman per se)
Kinetic Duplication: Jamie Madrox creates an identical physical living duplicate of himself upon any physical impact, possibly via extradimensional mass acquisition similar to the process used by Ant-Man or the Hulk. This process is spontaneous and cannot be prevented by Madrox. Although he can create multiple duplicates, and the duplicates themselves can also replicate, each is only able to create one duplicate at a time; he has been seen to produce around forty duplicates before no more would be created. The duplicates think, feel, and act independently, though usually guided by the original. Each tends to manifest one aspect of Madrox's personality, which increases in strength with lengthier separation from the original; these traits have recently become more extreme. Madrox is telepathically and empathetically linked to his duplicates, suffering severe, potentially fatal, trauma if one dies. If Madrox himself were killed, it is not known whether any existing duplicates would continue to function independently; it is said in theory, that if the original Madrox was killed, that one of his active dupes is capable of taking over as the new original and will assume the dominant abilities and collective personality that the original Madrox had. It is virtually impossible to distinguish the original from the duplicates. His powers have increased during his life. He was once able to create hundreds of dupes by himself. He has even gained better control of his powers, he has learned to prevent his body from producing duplicates, and has even been shown at one time to have duplicated without kinetic impact.
Duplication Absorption: The original Madrox can absorb them back into himself at will, at the same time absorbing the memories, skills and experiences of the duplicate. The only limit to this power is he can't absorb a dead dupe.
* Duplication Experience Transference: Madrox merges back, he retains memories (albeit somewhat imperfect), knowledge, and experiences of the dupe. Madrox doesn't have to absorb his duplicates to absorb information from them, he automatically absorbs information from any of his dupes if it kills itself. * Duplication Healing: He also uses merging as a form of healing - Originally, uninjured Madri "shared" the damage when they reemerged (e.g., if an injured dupe merged with an uninjured Madrox, the resulting Madrox had an injury half as severe as the original injury). Now, however, the core Madrox can reabsorb injured or even near-dead dupes without taking on any of their physical injuries at all.