Casinos are places where people gamble on games of chance, usually using cards, dice or balls. The word is most closely associated with Las Vegas, where many famous movies and TV shows have been filmed, but there are casinos all over the United States. Some are located in large cities, while others can be found in more remote areas.

In the United States, there are over 200 legal land-based casinos, with Nevada and New Jersey having the most. Most states allow casino gambling, but some have restrictions on certain types of gaming or prohibit it altogether. Some of these states also prohibit online gambling.

Most modern casinos use technology to oversee their games and prevent cheating or fraud. In some cases, this is as simple as using cameras to monitor the activity at a table; in other cases, it involves sophisticated computer systems that track bets minute-by-minute and alert operators when statistical deviations occur. Slot machines are a major source of income for American casinos, and most have special counters that record player activity.

Something about the environment in a casino seems to encourage people to attempt to cheat, steal or scam their way to winnings. This is a significant reason why casinos spend so much time, effort and money on security. Some casinos also provide a variety of responsible gambling programs, and state laws typically include provisions for funding these efforts. For example, a casino may post signs that warn players of the dangers of gambling and provide contact information for organizations that can offer specialized support.