Online interventions for gambling problems hold a strong potential to help people with gambling concerns. However, there are no trials, to-date, that have been able to demonstrate the effectiveness of such an intervention. The current trial will compare participants provided access to an online gambling intervention to those assigned by chance to a no intervention condition in order to test the efficacy of one such Internet intervention for gambling.

Participants will be recruited through Amazon's MTurk crowdsourcing platform. Potential participants identified as problem gamblers who are interested in quitting or reducing their gambling in the next 6 months, or often think about it, based on an initial survey will be invited to complete additional surveys at 6 weeks and 6 months. Those who then agree to be followed up will be randomized to access an online intervention for gambling or a no-intervention website. These participants will then be contacted again at 6 weeks and 6 months to ask about their gambling, and their impressions of the online intervention. The primary hypothesis to be tested is that participants receiving access to the online gambling intervention will report a greater reduction in number of days gambling and in NODS scores at 6-month follow-up than participants in the no intervention control condition.

Inclusion Criteria:

• 18 years of age or over
• A score of 5 or over on the Problem Gambling Severity Index (PGSI)
• Thinking about cutting down or quitting their gambling (in next 6 months, or state that they are thinking about it most or almost all of the time)
• Willingness to complete a 6-week and 6-month follow-up survey