A casino is a building or room where people can gamble on games of chance and skill. The gambling is legalized by state or national governments and overseen by a regulatory body. The largest casinos are found in Las Vegas, Nevada and Atlantic City, New Jersey, although a growing number of states are legalizing casino-type operations. The casino industry brings in billions of dollars each year to corporations, investors, local government and Native American tribes. Successful casinos also draw crowds of visitors and generate revenue for transportation, hotels, restaurants, shops, shows and other amenities.

Something about gambling seems to encourage people to cheat, steal or otherwise try to manipulate the outcome of a game. This has led to a need for security, ranging from casino surveillance personnel on the floor to watch patrons and games through one-way mirrors, to electronic systems that track betting patterns in table games and reveal any statistical deviations.

Unlike lotteries and Internet gambling, casino gaming is a social activity that involves players in direct interaction with each other. Gamblers sit around tables or slot machines in groups, and often shout encouragement or argue over strategies. Waiters circulating throughout the casino offer alcoholic drinks and nonalcoholic beverages for free or at a nominal cost. In addition to gambling, casinos feature entertainment events, including concerts and stage shows. Casinos are designed to be exciting and visually appealing, with bright colors and noise. Some have fountains, towers or replicas of famous landmarks.