Before Arnold Schwarzenegger was cast in his iconic role as the Terminator in the famous film franchise, ex-NFL running back and world-famous almost-convicted murderer O.J. Simpson was almost cast in the role. The reason that O.J Simpson was almost cast in the role was due to his size. At first, studios wanted Arnold to play Kyle Reese, the protagonist in the film. In order to do that, they argued, the Terminator, the villain in the first film, would need to be as big or bigger than Arnold. Simpson was one of the rare men with the size to fill that need.