With all the aforementioned time in development hell, Mad Max: Fury Road has been in existence in script form for over a decade at least. That's a massive amount of time to fine tune the script. In fact, George Miller had enough time that he came up with a second script (Furiosa) and reportedly parts of a third. Movies, even action flicks, live and die by their scripts. That's why Terminator 2 was incredible while Terminator 3 turned out to be a pale imitation of its predecessor. But there should be no such problem with Fury Road, which gives it a leg up on competition that has been rushing to get a script done by the start of production.