Abstract
This analog study examined whether warning and brief intervention messages would increase gamblers' knowledge of odds, alter level of irrational beliefs, and influence gambling behaviour on a computerized roulette game. College‐age participants (N = 101) were matched on level of gambling irrational beliefs and self‐efficacy and then randomly assigned to receive a warning message, a warning message plus information on limit setting and irrational beliefs, or a video about gambling history. Participants were then allowed to play roulette. In contrast to those who watched the video only, participants in the two message conditions showed greater knowledge of the risks of gambling. The limit‐setting strategy produced significant reductions in gambling‐related irrational beliefs. Across conditions, participants did not gamble differently. These results suggest that warning messages might have informational value and that limit‐setting strategies hold promise for producing cognitive change in gamblers. Under the present analog procedure, such messages did not significantly affect gambling behaviour.