The casino, also known as the gaming house or gambling hall, is a place where people gamble by playing games of chance or skill. Gambling games are most commonly played in casinos, but can also be found in racetracks (racinos), on cruise ships and in bars and restaurants. The casino business brings in billions of dollars each year for the companies, investors and Native American tribes that operate them. It is also a major source of revenue for state and local governments that license them and regulate them.

In general, the casino strives to create a mood of wealth and excitement that is intended to make its patrons feel as though they are experiencing a unique and exclusive experience. The use of bright and sometimes gaudy floor and wall coverings, as well as carefully controlled lighting, contribute to this atmosphere. Many casinos have no clocks on their walls, as it is believed that this helps the patrons lose track of time and thus focus more closely on their gambling activities.

The Bellagio in Las Vegas is perhaps the best-known casino in the world, and its fountain show and luxurious accommodations have made it a must-see destination for tourists. Other famous casinos include the Casino de Monte-Carlo in Monaco and the Casino Lisboa in Lisbon, both of which have been featured in movies and television shows. In the twenty-first century, casinos have become choosier about whom they allow to play. They now concentrate their investments on high rollers, who are able to gamble for tens of thousands of dollars and who receive comps (free goods or services) such as free hotel rooms, meals, tickets to shows and even limo service.