A casino, also known as a gaming house, is an establishment for certain types of gambling. Some casinos specialize in one type of game, while others offer a wide variety of games. Casinos are usually located near or combined with hotels, resorts, restaurants, retail shops, cruise ships or other tourist attractions. Some casinos are also known for hosting live entertainment events such as stand-up comedy, concerts or sports matches.

In the United States, there are 40 legalized casinos. The largest casinos are in Las Vegas, Nevada; Atlantic City, New Jersey; and Chicago, Illinois. Most of these casinos have multiple floor levels and contain many different gambling activities, including poker rooms, blackjack tables, roulette wheels, craps tables and slot machines. In addition, many casinos feature exotic Far Eastern games such as sic bo, fan-tan and pai gow.

The economic model of most casinos is based on the premise that they will lose money on some bets, but earn enough from other bettors to cover those losses. This allows them to make a profit, on average, over time. Because of this virtual assurance of gross profit, casinos regularly reward big bettors with free or reduced-fare transportation, hotel accommodations, expensive meals and spectacular shows.

Because large amounts of money are handled within a casino, both patrons and staff may be tempted to cheat or steal, either in collusion with each other or independently. For this reason, most casinos have substantial security measures in place. These often include a physical security force and a specialized surveillance department.