Gambling is an activity that involves risking something of value (money or belongings) on events with random or uncertain outcomes. It can be done in many ways, from buying a lottery ticket to betting on sports and politics. It can even be done online, with virtual casino games and scratch cards. It can be a fun and entertaining pastime, or it can lead to negative effects for the gambler and those around them.

Historically, the term “gambling” has been used to describe activities that involve skill, as well as those that are entirely random or uncertain. The former, such as a game of marbles, may include some elements of skill; the latter is totally random and cannot be predicted or improved upon. However, the vast majority of gambling activities have two common features – an element of risk and an uncertain outcome.

In modern times, the development of a wide range of gambling opportunities and the proliferation of electronic devices has changed the way people gamble. This change has had profound implications for the understanding of gambling problems and how they are classified in psychiatric manuals, such as the Diagnostic and Statistical Manual of Mental Disorders (DSM) published by the American Psychiatric Association.

It has also meant a change in how people think about pathological gambling, from the perception that it is just like substance abuse to the recognition that it is much more complex and likely to occur with other psychological disorders. It has also led to a greater understanding of how the brain responds to gambling, and how this affects individuals and families.