There's an incident where a man is cheating at blackjack, and a couple of security guys sidle up to him and jab him with a stun gun. And it knows about how casinos don't like to be stolen from. It also knows how to skim from the other games, and from food service and the gift shops. Assuming you could steal 25 percent of the slot-machine take - what would you do with tons of coins? How would you convert them into bills that could be stuffed into the weekly suitcase for delivery to the mob in Kansas City? 'Casino' knows. The first hour plays like a documentary there's a narration, by Rothstein ( Robert De Niro) and others, explaining how the mob skimmed millions out of the casinos. The movie explains how such a thing came to happen to him. The movie opens with a car bombing, and the figure of Sam 'Ace' Rothstein floating through the air. Like ' The Godfather,' it makes us feel like eavesdroppers in a secret place. It's based on a book by Nicholas Pileggi, who had full access to a man who once ran four casinos for the mob, and whose true story inspires the movie's plot. Martin Scorsese's fascinating new film 'Casino' knows a lot about the Mafia's relationship with Las Vegas.