A casino, also known as a gambling house, is an establishment that houses various games of chance and provides customers with the opportunity to gamble. Casinos may also offer other types of entertainment and are found in many cities worldwide. In some countries, casinos are licensed and regulated by government authorities.

Modern casinos are often massive, resort-like complexes that feature hotels, restaurants, non-gambling games rooms and spas, as well as a huge selection of gambling opportunities. They compete to attract and keep customers by offering ever-more elaborate facilities, such as theme parks and water shows, while racing to be the biggest in their region or even the world.

But while lighted fountains, shopping malls and lavish hotels help attract customers, casinos would not exist without games of chance. Slot machines, roulette, baccarat, blackjack and craps generate the billions of dollars in profits that casinos bring in every year.

Something about the presence of large amounts of money encourages patrons to cheat, steal and scam in ways that might not occur at other places of entertainment. For this reason, casinos spend a great deal of time, effort and money on security measures. Among these are security cameras that cover the entire casino floor and can be adjusted to focus on suspicious patrons. Chips with built-in microcircuitry are used to replace real money at the tables, so that the amount bet is tracked minute by minute. Windows and clocks are often removed from the gaming area, so that players might lose track of how long—and how much—they have been gambling.