A casino is a gambling establishment where people can place wagers on various games of chance or skill. The most common games are blackjack, craps, roulette, and poker. In the United States, most casinos are located in Las Vegas, although more than 40 states have legalized casino gambling.

The casino industry is a major source of employment, especially in cities with large numbers of such establishments. It has also become a significant tourist attraction in its own right. In a 2003 poll conducted by Gallup, 30% of Americans reported having visited a casino within the previous twelve months.

Most casino games have an inherent long-term advantage for the house, referred to as the house edge or vigorish. However, some games allow players to reduce this house advantage with practice and knowledge. These skilled players are known as advantage players.

Because of the large amounts of cash handled in a casino, both patrons and staff may be tempted to cheat or steal. To counter this, most casinos use a variety of security measures. These include catwalks in the ceiling above the gaming floor that allow surveillance personnel to look directly down on the activities of tables and slot machines through one-way glass.

A casino’s profitability depends on its ability to attract and retain customers. To this end, it employs a variety of marketing and promotional tactics. For example, it may offer special inducements to big bettors such as free spectacular entertainment or transportation and elegant living quarters.