A casino (also called a gambling house or a gaming establishment) is an institution for certain types of gambling. Casinos are often combined with hotels, restaurants, retail shops, cruise ships or other tourist attractions. They may also be located within or alongside other entertainment venues, such as theatres and arenas. In some countries, casinos are licensed and regulated by law. Others are unlicensed and operate illegally. In either case, the primary objective of a casino is to attract and keep patrons through a combination of games of chance, and other forms of social amusement such as live entertainment.

Many casinos have a bright and exciting interior design, and use colors to stimulate the senses of their patrons. They also employ lighting techniques and sound effects to evoke particular emotions, including excitement, suspense, fear, romance, or tranquility. In addition, many of them have music playing in the background to heighten the atmosphere and encourage play.

Some casino games have a degree of skill involved, but most depend largely on luck. Some of the most popular are roulette, craps, baccarat, and blackjack. Some casinos specialize in a specific game, such as keno, bingo, or sic bo.

In the United States, most people who go to a casino do so with family members and friends or in organized groups. According to a 2004 survey by Peter D. Hart Research Associates and Luntz Research Companies, about nine out of ten casino gamblers view the activity as a fun night out, and nearly all go on a regular basis. To attract and keep customers, most casinos provide a variety of incentives known as comps (complimentary items or free services).