To start off with, I was skeptical to hear they were making the book World War Z into a movie, especially since there was an emphasis on Brad Pitt headlining it. World War Z is a collection of different people, events, documents chronicling the worldwide zombie outbreak. The movie bears little resemblance to the book...Therefore, I can't judge the movie on how well it adapts the book because it doesn't (It doesn't even have the same type of zombies). What I can do is judge it as a movie and as a zombie flick.
As I mentioned before, there's no amount to stupidity in this movie. I wanted to throw up my hands in disgust/slap characters upside the head a dozen different times. It might as well be a teenage slasher flick. Various characters keep talking about how impressive Brad Pitt's character is, and all that he's done, but their words are weaker than his actions. He's as dumb as everyone else. He has zero credibility as the respected professional he is. Through half the movie, he runs around with a hipster scarf. Why? Because he wants to look cool for the zombies? I mean, does this scarf serve a useful purpose?
This is only one example of several ludicrous situations.
Despite all this, the fast pace of the movie kept me entertained. It's at least a fresh take on the traditional zombie post-apocalyptic movie and involved a little more of how different parts of the world would act. And again, at least in this movie, not all the military men are idiots.
Apparently, this movie was in a tug-a-war contest between Brad Pitt's company and one headed by Leonardo DiCaprio. I'm curious as to how the latter would have interpreted the movie/book, had he won out. The world will never know.
PS. If you keep your eyes peeled, you can see Matthew Fox for a few seconds. Apparently he had a bigger role in the movie originally, but all of his scenes were cut. Boo.