Gambling is any form of risk-taking in which people stake something valuable – a sum of money, a physical or virtual good, or even their lives – for the chance to win an uncertain amount of money or other reward. It can occur in a casino, on the internet or at other venues such as sports games or horse races. People gamble for a variety of reasons; mood change and the dream of winning are popular motives, as are a desire to socialize with others. The addictive aspect of gambling is often linked to the brain’s reward system. Like video games, gambling creates a pattern of rewards and losses, optimizing the reward schedule to ensure continued engagement.

Harms related to gambling have been identified through a number of methods, including literature reviews, qualitative research with people who gamble and their affected others, focus groups, analysis of public forums, and other data sources. The initial themes that emerged from these analyses were grouped into two separate categories that were then used to generate a conceptual framework and catalogue of harms.

The framework was designed to clarify the distinction between a harmful outcome and a harmful behaviour, as well as to highlight the complexities of harms related to gambling. A key insight was that harms experienced through gambling may persist after a person has stopped engaging in the behaviour, or they may continue to emerge as a result of someone’s continuing participation in gambling (termed legacy harms). These are also often co-morbid with other harmful behaviours and reduced health states, including alcohol use and depression.