A casino is a gambling establishment that houses many different games of chance, and often some games that involve skill. Craps, roulette, blackjack and poker are all popular casino games. Casinos also offer other amenities like restaurants, spas and top-notch hotels. A casino’s revenue is derived from the money bet by patrons, and from a percentage of the winnings from the games, known as the house edge.

Something about gambling (maybe the proximity to large amounts of cash) seems to encourage people to try to cheat, steal or scam their way to a jackpot. That’s why casinos invest a lot of time, effort and money on security. It starts on the casino floor, where pit bosses and managers watch over table games with a keen eye for blatant cheating, like palming cards or marking dice. Dealers are trained to spot a variety of other subtle patterns, from the location of bets to expected reactions and motions.

But even when there are no obvious signs of cheating, the odds for every casino game are designed to win the house money. There’s a built in mathematical advantage for the casino that can be very small, less than two percent on average, but that small advantage adds up over millions of bets and earns the casino billions of dollars a year. Some games have a smaller house edge than others, and the house may or may not make this information available to players.