Aim: To provide an overview of gambling and problem gambling in Britain, including historical background, current regulations and the recognition, prevalence and treatment of problem gambling. Methods: A new theory, Gambling Restraint Erosion Theory (GRET), is used as a framework for understanding the history of gambling regulation in Britain in the 20th century and evidence about the prevalence of gambling and problem gambling, as well as public attitudes towards gambling, in Britain in the first decade of the 21st century. Findings: Restraints on gambling were progressively dismantled as regulation moved from partial prohibition, to tolerance, and then to liberalization by the turn of the millennium. British adult gambling prevalence surveys carried out in 1999/2000, 2006/07 and 2009/10 suggest that the British public is still relatively restrained in its engagement in gambling, and is still suspicious of gambling. There is evidence from the last of those surveys that engagement in some forms of gambling, and the prevalence of problem gambling, have risen, and that attitudes have become less negative towards gambling. Conclusions: Restraints which kept British gambling circumscribed, and the prevalence of problem gambling low, may be in the process of being eroded. Meanwhile, an effective public health response to problem gambling is constrained by lack of Department of Health interest and a failure to develop a research and treatment base independent of the gambling industry.