A casino is a gambling establishment that offers several types of gambling. Although a casino may add other features like restaurants, free drinks, stage shows and dramatic scenery to draw in customers, it’s primarily a place where people can play games of chance.

In the United States, about 51 million adults—a group equivalent to a quarter of all Americans over 21—visited casinos in 2002. Worldwide, the figure could be double that or more. In many countries, the growth of casino gaming has been fueled by an increase in tourism.

Despite the large number of people who gamble at casinos, few actually lose money. The reason is that each game has a built in advantage for the casino. This advantage, often less than two percent, is known as the house edge. Casinos make money by collecting this edge on all bets placed.

In addition to the house edge, casinos employ a variety of security measures. These range from basic rules of conduct to high-tech “eyes-in-the-sky” systems that can detect a tampering or cheating attempt by analyzing the pattern of betting and other movements on the casino floor. In addition, security personnel regularly walk the casino floors to observe patrons and spot suspicious behavior. Many casinos also offer complimentary items—or comps—to big spenders, such as rooms, meals, show tickets and limo service. This is designed to encourage gambling and reward repeat business. It is a strategy that works; studies show that gamblers who visit casinos often do so again and again.