A casino is a gambling establishment that houses games of chance and skill. Games are played at tables and machines, and successful casinos make billions of dollars each year for the companies, investors, Native American tribes, and state and local governments that operate them. Some casinos have elaborate hotels, towers and replicas of famous buildings; others are smaller and resemble old-time saloons. The casino business is regulated and audited by government agencies to prevent cheating and other violations of gambling law.

In addition to security guards and video cameras, modern casinos use technology to monitor the games themselves. For example, betting chips have built-in microcircuitry that enables them to be tracked minute by minute; roulette wheels are monitored electronically to detect any statistical deviation from expected results. Table managers and pit bosses also keep close watch over the players, noting their movements and observing their reactions to the game.

The glitz and glamour of the modern casino may seem like an aberration, but gambling has been around for centuries. Miners chasing gold in the West took a break from their mining work by playing poker in a local card room, and mobsters provided the money for many early Las Vegas casinos.