A casino is a facility where people can gamble for real money by playing games of chance, or by using video poker machines. Most games have a statistical advantage for the house, which can be small (less than two percent), but over time it adds up. Casinos earn money by taking a percentage of bets, which is called the vig or rake. Some casinos also offer complimentary items or comps to players.
Because of the large amounts of cash handled within casinos, security is a major concern. The usual method of security is to use cameras, but some casinos go further. They have catwalks on which personnel can look down, through one-way glass, directly onto the table game areas. Similarly, some casinos have tables that are entirely enclosed and operated by electronic devices; these allow the casino to monitor exactly how much is wagered on each bet minute by minute.
In the past, organized crime groups ran many of the largest casinos in the United States, including those in Las Vegas and Reno. But federal crackdowns and the ability to lose a gaming license at the slightest hint of mob involvement forced these groups to pull back. Despite this, legitimate businessmen with deep pockets, such as real estate developers and hotel chains, bought out the mobsters and began operating their own casinos. Donald Trump and the Hilton hotel chain, for example, each own several casinos. The casinos they run often feature fountains, giant pyramids and towers, as well as luxurious rooms and restaurants.