In casting Sully, Cameron had two very specific, very different visions in mind. 

Plan A? Matt Damon. "The Bourne Identity" star told GQ in 2019, "When he offered it to me, he goes, 'Now, listen. I don't need anybody. I don't need a name for this, a named actor. If you don't take this, I'm going to find an unknown actor and give it to him, because the movie doesn't really need you." Cameron also offered Damon 10 percent of whatever "Avatar" would end up making at the box office — which would have been, according to unofficial calculations, enough money to buy a small country (or about $250 million). Damon ultimately declined, citing prior commitments to the "Bourne" franchise. "I realized in having to say no that I was probably passing on the chance to ever work with him," he added. "So that sucked and that's still brutal. But my kids are all eating. I'm doing ok."

True to his word, Cameron proceeded to cast an unknown actor as Jake Sully. He eventually hired Sam Worthington, who had acting experience but wasn't a household name. Worthington recalled the audition process took over a year. Reflecting a decade later, he said, "I didn't look at them as auditions. I looked at the process as, 'Well, if I don't get it, at least I got to work with Jim Cameron in some respect.'" Worthington's screen tests were "very collaborative and really quite painless."