Gambling involves the exchange of real money or material values for an outcome determined at least in part by chance. People engage in gambling for a variety of reasons, including social interaction, enjoyment, and the hope of winning. The prevalence of gambling varies across countries and cultures. A small number of adults experience a gambling disorder, which is defined in the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) as a comorbidity with other disorders and is associated with significant distress and impairment.

Many people do not have a gambling problem and are able to enjoy the occasional bet without experiencing distress or impairment. However, for a small percentage of people, gambling becomes compulsive and ruins their lives. Research suggests that about 2.5 million U.S. adults (1%) meet the criteria for a severe gambling disorder, and another 5-8 million (2-3%) would be considered to have mild or moderate gambling problems.

The risk of gambling addiction increases when a gambler is in a vulnerable situation. This may include a lack of financial resources, family or work responsibilities, and personal challenges. The likelihood of developing a gambling problem is also increased by certain environmental factors. These include the existence of a disproportionate concentration of gambling venues in disadvantaged areas and the aggressive promotion of gambling products in social media and popular culture.

Gambling is a complex issue, and different interests frame the issues in various ways. For example, elected government leaders often support gambling to bring in tourists and other revenue. Bureaucrats in agencies that are promised gambling revenue often support the introduction of new casinos, while casino owners tend to oppose such initiatives when they think they might lose their business.