One of the things that Terminator: Genisys's producers have had to bare in mind is how tainted the franchise has become. The third film in the series was kind of a dud, but Terminator Salvation was even worse - for many, myriad reasons, but the lack of any Arnie probably didn't help ingratiate the film to audiences, either. In a canny move, Schwarzenegger has been brought back for the new film, reprising his role as the formerly-villainous but now really quite nice T-800 robotic assassin from the future. Much like the casting of Clarke, however, this opened up a whole bunch of other questions. Like, Arnie is noticeably older than he was when he made the other films: how do you explain that when he's supposed to be a robot? Robots don't age! There was speculation that some CG touching up might be on the cards, but series creator James Cameron came up with a much more novel solution. It'll be explained that the "fake" flesh surrounding that terrifying metal skeleton ages just like normal skin! It's genius in its simplicity. Sort of.