A casino is a place where people gamble by playing games of chance, in some cases with an element of skill. The casinos make their money by taking a percentage of the total amount of bets, or “the rake,” in poker, blackjack and other table games. In addition, casinos earn income from slot machines and video poker. They also profit from the gifts they give to players, known as comps, and the fees charged to host events, such as weddings.

While gambling almost certainly predates recorded history, the modern casino as a place where people could find a variety of ways to gamble under one roof didn’t appear until the 16th century. That was when a craze for gambling spread across Europe, with wealthy nobles forming private clubs called ridotti where they could play their favorite games without fear of legal prosecution.

In the United States, casino gambling began appearing in the 1980s when various American Indian reservations changed their laws to permit gambling. Today casinos can be found all over the world, from Atlantic City to Macau.

To ensure the fairness of their games, casinos have strict rules that must be followed. Dealers are heavily trained to spot blatant cheating like palming cards or marking dice, and pit bosses and table managers keep a closer eye on patron behavior to spot suspicious patterns. Elaborate surveillance systems offer a high-tech “eye in the sky” that allows security personnel to watch every table, window and doorway at once; electronic chips have built-in microcircuitry to monitor bets minute by minute, and roulette wheels are monitored regularly for statistical deviations.