A casino is a building or room in which gambling games are played. Modern casinos offer a variety of entertainment, food and drink, as well as gaming. Some are massive resorts, while others are small card rooms or even bars. Many states have legalized casinos, and the industry generates billions of dollars each year for owners, investors, Native American tribes, and local and state governments.

While casinos offer a wide range of activities, they are primarily designed to attract and keep gamblers. They often have bright lights and elaborate decorations. Some use acoustic effects, such as bells and whistles, to add to the excitement of gambling. Many casinos are located near water, or on the shores of lakes and rivers. Some have a circus or other live entertainment as another way to draw in customers.

In the United States, casinos are mainly located in Las Vegas and Atlantic City, although there are some off-shore locations. Most casinos are operated by private corporations, with a few run by the government and a few by Native American tribes. Some states have regulated the number of casinos, while others have prohibited them entirely.

Because large amounts of money are handled within a casino, it is easy for people to cheat and steal, either in collusion with each other or independently. To counter this, casinos employ a variety of security measures. Many have cameras throughout the facility, and some of the machines are wired to computers that monitor patterns and can quickly discover statistical deviations from expected results. Casinos also place a great emphasis on security personnel, who are trained to spot suspicious behavior.