Gambling is the wagering of something of value (money, property, etc.) on an uncertain outcome of a game of chance or skill, where instances of strategy are discounted. Gambling takes place in a variety of settings, including casinos, horse races, sports events and on the Internet.

People gamble for the thrill of winning, and to relieve anxiety or boredom. In addition, gambling can provide social interaction and entertainment. However, many gamblers develop a pathological addiction to gambling, which is classified as an impulse control disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM). Pathological gambling is a complex compulsion triggered by environmental factors, such as an environment conducive to betting and social pressure to participate; it also results from genetic or physiological predisposition.

Although gambling does create some positive economic impacts, such as increased revenues and tourism, the negative impacts can outweigh these benefits. The negative impact on personal health and well-being is known as a social cost of gambling, which is not quantifiable in monetary terms. A health-related quality of life approach, such as disability weights (DW), can measure these aversive impacts.

While gambling can take place in some private settings, it is more common to find groups of friends or coworkers engaging in games of chance together. Examples of such games include card games like poker, blackjack or bridge, and dice games such as roulette or craps. Some such private games are played at home, while others involve a higher level of risk and reward.