A casino is an establishment for gambling. Most casinos are located in or combined with hotels, resorts, restaurants, retail shops, and/or cruise ships. Some casinos specialize in specific types of games, such as poker or craps. Others focus on entertaining and luring in new customers with luxury services like spas and golf courses.

In the United States, casino gambling became popular after World War II. Mafia gangsters had a lot of cash from their drug dealing, extortion, and other illegal rackets and were willing to put it into casinos because of the huge potential profits. They financed many of the first Las Vegas casino buildings and even took sole or partial ownership of some. Mob involvement in casinos eventually prompted federal authorities to crack down on the business and drive mafia members out of it.

Casinos make money by charging bettors a small percentage of their total bets, called the house edge. This may be as low as two percent on some games, but it adds up over the millions of bets placed in a single casino. This profit allows casinos to build extravagant hotels, fountains, pyramids, towers, and replicas of famous landmarks.

Because of the large amounts of money handled within a casino, patrons and employees may be tempted to cheat or steal. To discourage this, casinos employ a variety of security measures. These may include cameras that cover the entire casino floor, high-tech eye-in-the-sky surveillance systems, and staff who patrol the premises looking for suspicious patrons.