A casino is a large building or group of rooms where people can gamble on games of chance, in some cases with a skill element. The house edge, a mathematically determined advantage for the casino, is built into every game and can be less than two percent in some cases. The casino makes money by charging players a commission on their bets, which is called the vig or rake. It also gives out complimentary goods or services to “good” patrons, known as comps. These can include free hotel rooms, food, show tickets or even limo service and airline tickets.

In the early days of casino gambling, gangsters controlled many casinos. They put in their own capital and even took part ownership in some. Federal crackdowns on mob money and the taint of illegal gambling made legitimate businessmen wary to get involved, but soon enough big-money investors like Donald Trump and the Hilton hotel company got their hands dirty and began building Las Vegas and Reno casinos.

Modern casino security is very sophisticated. Employees patrol the floor, observing players to make sure that they’re not cheating (palming, marking or switching cards, for example). The pit bosses and table managers have a much wider view of the tables, looking for patterns of betting that might indicate a pattern of cheating. The casino’s cameras, sometimes hidden behind a mirrored wall or placed in a room filled with banks of monitors, act as a high-tech eye-in-the-sky to watch every table, doorway and window.