The intervention is a Web-based, computer-tailored game in which adolescents receive personalized
feedback on their drinking behavior aimed at changing motivational determinants related to this behavior. The
development of the game is grounded in the I-Change Model. A CRTC is conducted to test the effectiveness of the
game. Adolescents are recruited through schools, and schools are randomized into the experimental condition and
the control condition. The experimental condition fills in a baseline questionnaire assessing demographic variables,
motivational determinants of behavior (attitude, social influences, self-efficacy, intention) and alcohol use. They are
also asked to invite their parents to take part in a short parental component that focusses on setting rules and
communicating about alcohol. After completing the baseline questionnaire, the experimental condition continues
playing the first of three game scenarios. The primary follow-up measurement takes place after four months and a
second follow-up after eight months. The control condition only fills in the baseline, four and eight month follow-up
measurement and then receives access to the game (i.e., a waiting list control condition). The effectiveness of the
intervention to reduce binge drinking in the previous 30 days and alcohol use in the last week will be assessed.
Furthermore, intention to drink and binge drink are assessed. Besides main effects, potential subgroup differences
pertaining to gender, age, and educational background are explored.