A casino is a gambling house where a variety of games of chance can be played. The games are usually played against the house, with some requiring skill, such as poker and blackjack. The casinos make their money by taking a percentage of the bets, called the vig or rake. Some casinos also give out free goods or services to certain players, called comps.

Although gambling almost certainly predates recorded history, the modern casino evolved in the 16th century when a European gambling craze was at its height. During this time, Italian nobles would often hold private parties in their homes, known as ridotti, where they would gamble for entertainment and socialize with friends. Although gambling was technically illegal in Italy at the time, most gamblers were rarely questioned by authorities and the ridotti grew in popularity.

Today, the average casino is like an indoor amusement park for adults, with musical shows, lighted fountains and shopping centers to draw in customers. But casinos would not exist without the millions of bets placed each year by their patrons. Slot machines, poker, blackjack, baccarat, craps and other games of chance generate billions in profits for the casinos each year.

Casinos employ a large number of people to ensure that everything runs smoothly. Security starts on the casino floor, where dealers and pit bosses keep a close eye on each game and can quickly spot any blatant cheating by patrons such as palming or marking cards. In addition, many casinos use sophisticated video surveillance and computer monitoring to superintend each game. For example, betting chips have built-in microcircuitry that interacts with the electronic systems on the table to allow casinos to oversee each bet minute by minute and instantly detect any statistical deviation from expected results.