A casino (from Latin kasino) is an establishment for certain types of gambling. Casinos are commonly built near or combined with hotels, resorts, restaurants, retail shops, cruise ships and other tourist attractions. They are also known for hosting live entertainment such as stand-up comedy, concerts and sports events. Some casinos are operated by government-sanctioned or licensed gambling clubs, while others are open to the general public.

Gambling almost certainly predates recorded history, with primitive protodice and carved six-sided dice among the oldest archaeological finds. But the first casino as we know it did not appear until the 16th century in Venice, during a gambling craze that saw many Italian aristocrats gathering in private houses called ridotti to gamble and feast on elaborate meals. These were technically illegal, but the authorities rarely bothered with them.

Modern casinos look like an indoor amusement park for adults, but the vast majority of their profits come from games of chance and skill. Slot machines, blackjack, roulette and craps generate billions in revenue for U.S. casinos each year. But even more money is generated by a less obvious source: the house edge. This is the percentage of the total bet that is taken by the casino, a number that varies by game.

The house edge is how casinos make their money, and it is why the industry has developed sophisticated security measures. In addition to surveillance cameras, most casinos have catwalks in the ceiling that allow security workers to watch through one-way glass at tables and slots from above. Moreover, gaming chips have microcircuitry that allows the casino to monitor their exact movements minute by minute, and roulette wheels are electronically monitored to quickly discover any statistical deviations from expectations.