A casino is a facility for certain types of gambling. It is also an entertainment complex, often combined with hotels, restaurants and/or retail shopping. Casinos typically feature slot machines and/or table games such as poker, roulette, baccarat, blackjack, craps, and more. In the United States, casinos are most popular in Nevada and New Jersey, with most gaming revenue coming from Las Vegas.

A small percentage of the bets made in a casino give it a mathematical advantage that earns it money over time. This is sometimes called the house edge, and it varies by game. Regardless, casinos make billions of dollars in profits every year. This allows them to build elaborate fountains, hotel towers and replicas of famous landmarks. In addition, casinos give out free items to gamblers known as comps, which can include hotel rooms, food and drink, show tickets, and even airline flights.

The large amounts of money handled within casinos create opportunities for patrons and staff to cheat, in collusion or independently. To combat this, most casinos have security measures in place. These range from a highly visible presence of security guards to sophisticated surveillance systems. For example, a high-tech eye-in-the-sky system watches every table and window in the casino, and is adjusted by security workers to focus on specific suspicious patrons.

Because casino games have a negative expected return, they attract people who are willing to take a risk in exchange for an opportunity to win money. This demographic has helped fuel the growth of casino gambling around the world. From the elegant spa town of Baden-Baden in Germany to smoky backrooms filled with dice and cards in downtown Brooklyn, casino owners have sought ways to attract the most customers while keeping them happy.