Gambling involves risking something of value (money or other items) on an event that is at least in part determined by chance, in the hope of gaining something of greater value. This includes billiards, bingo, casino games, card games, scratch tickets, and sports betting. While many people gamble, gambling can cause harm to anyone and may have negative impacts on relationships, work or study performance, and even lead to serious debt or homelessness. In addition, harms from gambling can affect children and family members, and have long-term effects that span generations.

Harmful gambling can have a significant economic impact and is a major source of addiction and problem behaviour, which in turn leads to social and family problems and even suicide. However, it is difficult to measure and quantify gambling-related harm because of the stigma associated with seeking help, as well as a lack of available resources. Moreover, governments often receive substantial taxation revenues from gambling and so have a vested interest in promoting the industry, which may create conflicting incentives to reduce harms.

It is important to understand what constitutes gambling, as this is used in legislation and regulations. Defining gambling can also help contextualize its potential harms, such as by assessing risk factors that can lead to addiction and identifying harmful behavior. A clear definition of gambling will allow governments to create responsible gambling measures that can prevent addiction and financial ruin. It is also important to remember that gambling can involve materials that do not have monetary value, such as marbles or collectible game pieces from games like Magic: The Gathering and Pogs.