A casino, also known as a gambling house or a gaming establishment, is an establishment where people can legally gamble. Casinos can be operated by governments, Native American tribes, private corporations, or charitable organizations. They may offer a variety of gaming activities, including poker, blackjack, roulette, craps, and video poker. Some casinos also feature restaurants and bars. In the United States, there are over 300 casinos.

Many casinos use a variety of marketing techniques to attract gamblers. They display positive customer reviews on their websites and social media pages, and record and post videos of happy winners. They also advertise special bonuses and promotions to encourage gamblers to spend more money. Casinos typically have a high profit margin, because they make money from the house edge and other hidden fees.

The house edge is the mathematical advantage that the casino has over players in games of chance or skill. This advantage is based on the fact that, for most casino games, there are fixed odds that determine how often a player will win or lose. In addition, the casino takes a percentage of all bets made on its machines or tables. This fee is known as the rake.

In the past, casinos attracted customers by giving out complimentary items, or comps, such as free drinks and food. These promotions are still used in some places, but in the twenty-first century casinos are becoming choosier about who they accept as patrons. They are increasingly focusing their investments on high rollers, or gamblers who place large bets, often in the tens of thousands of dollars. These gamblers are often given their own private rooms, away from the main casino floor, and receive a level of service that is a step above what most people get at the local bar.