Jake Sully was born and raised on Earth and grew up hearing about Pandora, a small moon orbiting the gas giant Polyphemus in the Alpha Centauri System. Though nothing is known of his childhood, he joined the Marines as an adult for the hardship involved and a cause to fight for. He suffered a spinal injury in an unspecified war while fighting in Venezuela. The injury was severe, leaving him paralyzed from the waist down.
Since his veteran benefits are not enough to pay for the surgery to repair his spine, he has no choice but to live out his life in a wheelchair. After a night of drinking, Jake starts a bar fight with a man who strikes a woman. After breaking up the fight, the bouncers throw him out into the street where he is approached by two RDA agents. After confirming his identity, the agents inform him that his identical twin brother, Tom, had been killed in a mugging. His brother was one of the selected few scientists chosen to participate in the Avatar Program, and one of even fewer avatar drivers. Tom had trained on Earth for three years in preparation for a tour on Pandora. He represented a significant investment on the part of the Resources Development Administration due to the inherent link between the pilot and the avatar he controls, as well as the enormous cost of creating an avatar. Since Jake is genetically identical to his brother, he can link with the avatar, saving the company the cost of creating a new one. After being offered significant compensation, he apprehensively agrees to take over his brother's contract and is put in cryosleep for the trip to Pandora.
