A casino is a facility where people can gamble on games of chance. Modern casinos are often designed with a theme, such as an Asian theme or a Western theme, and they feature many types of games, including slot machines and table games like poker, blackjack, and roulette. Casinos also have entertainment venues and dining options.

Casinos make money by charging a fee to patrons who play the games. This fee, known as the house edge, can be very small — less than two percent for most games — but over millions of bets, it adds up to a significant source of revenue for the casino. In addition, most casinos offer free drinks and food to attract customers. This free advertising is known as comping.

Slot machines account for a large part of casino profits. The player puts in a coin or paper ticket, pulls a handle or pushes a button, and watches varying bands of colored shapes roll on reels (actual physical ones or video representations). If the pattern matches a predetermined payout, the player receives a cash prize. Unlike other casino games, no skill or strategy can affect the outcome of a slot machine game.

Something about the gambling environment seems to encourage people to cheat, steal and scam in order to win. To counter this, casinos spend a lot of time and money on security. They monitor the games with cameras that can zoom in on specific suspicious patrons and they use sophisticated computer systems to supervise their games. For example, betting chips have built-in microcircuitry that interacts with electronic systems on the tables to oversee the exact amount of money being wagered minute by minute; and roulette wheels are electronically monitored regularly for any statistical deviation from expected results.