Matt Damon has had brushes with science-fiction fare in the past -- 2011's "The Adjustment Bureau," based on Philip K. Dick's short story, comes to mind -- but the actor is diving in, exoskeleton first, with Neill Blomkamp's "Elysium," out Wednesday (August 7).

Set in a future world in which the poor inhabit Earth and the rich live on a man-made colony far above, Damon plays Max, a blue-collar felon who must infiltrate the utopia in order to save his life.

A self-professed "huge" sci-fi fan, Damon cites "Blade Runner," "Star Wars" and "Alien" among his early favorites. But, as the Academy Award-winner told MTV News' Josh Horowitz, his love for the genre never translated into his own writing.

"I think I was always trying to write more something that I knew, something that was closer to me," Damon explained. "Not that this -- great sci-fi does feel familiar in a way. But I was always intimidated. It's so hard to kind of come up with a full, complete concept and follow that thought exercise all the way."

Perhaps, then, that's why Damon acts in sci-fi films, letting other screenwriters tackle the difficult task of world-building. It's a talent he recognized in "Avatar" director James Cameron (Damon famously turned down the film's lead role that ultimately went to Sam Worthington) and his "Elysium" director Blomkamp.

"I remember sitting with Cameron before he made 'Avatar,' and he described the world, and he described it as though he'd been there before," Damon recalled. "It totally existed as a real place, he just needed help to manifest it, right? He needed, like, 200 people to help him realize this place that already totally existed. It was like that with Neill."

In fact, the level of detail Blomkamp put into imagining his fictional universe surprised even Damon.

"He gave me this graphic novel that he created, and there was another book that came with it that was all weapon systems and vehicles -- stuff that's deep in the background of shots and is never featured," Damon explained. "But it's completely detailed, and he can explain how it works and why. It's just a level of detail. It makes it feel like you're talking to somebody who's describing a city to you that they've lived in. That, I think, is a huge similarity, and I suspect whether it's Ridley with 'Blade Runner,' any of those cases, the person has gone all the way down to the last detail."