A casino is a room or building in which gambling activities take place. People who gamble in casinos do so by playing games of chance or skill, including blackjack, poker and craps. The largest casinos in the world are found in Las Vegas, Nevada; Atlantic City, New Jersey; and Macau, China. There are also casinos in the United Kingdom, France and Monaco. In general, casinos offer a variety of games and services, including food, drink and entertainment.

Gambling is not without its problems, however. Patrons and staff may be tempted to cheat or steal, either in collusion or independently. To prevent this, casinos use a variety of security measures, from cameras to rules that require players to keep their cards visible at all times. Many casinos have elaborate surveillance systems with a high-tech “eye-in-the-sky” that allow security personnel to monitor the entire casino at once; each camera can be directed to focus on specific suspicious patrons by workers in a separate room filled with banks of security monitors.

Most casinos make their money by charging patrons a fee for the opportunity to gamble. This fee is often referred to as the house edge. It can be very small, but it adds up over time and millions of bets. In some games, such as poker where patrons play against each other, the casino takes a percentage of each pot, called the rake. In other games, such as slots and video poker, the casino’s advantage is built into the machine’s payout structure.