A casino (or gaming house) is an establishment for certain types of gambling. Casinos are most often associated with hotels, cruise ships or resorts, and they may also serve as standalone attractions. Some casinos host professional or recreational games of chance, such as poker tournaments. In addition to gambling, some casinos host live entertainment and have restaurants.

Despite their widespread availability, casinos vary greatly in size and style. Some casinos are renowned for their luxurious facilities and exclusive service, while others have a more casual atmosphere. Some are owned by big name entertainment companies, while others are independent and operate primarily in local markets.

In the United States, the most famous and largest casinos are in Las Vegas; some smaller cities such as Atlantic City, New Jersey, and Chicago are also major centers of casino activity. Some states have legalized casinos, while others have prohibited them. In the latter case, the casinos are often operated by American Indian tribes on reservations, which are exempt from state gambling laws.

Some casinos are best known for the high level of skill involved in their games; players with enough knowledge and technique to overcome the inherent long-term advantage of the casino, are referred to as “advantage” players. In some cases, the casinos have been designed to make use of technology to monitor and prevent cheating. For example, chips with built-in microcircuitry allow the casino to monitor the exact amounts of money wagered minute by minute and quickly discover any statistical deviations.