Disentangling real-world and virtual-world social norms: The persuasive elements and social psychological effects of a serious game

•This paper takes a novel approach to investigate the relative influence of real-world and virtual-world social norms on game outcomes.•The three alcohol use outcomes improved from pre-game to post-game.•Virtual-world norms have significant influence on attitudes toward drinking and drinking refusal self-efficacy.•As compared to virtual-world norms, real-world norms had no significant effects on alcohol use outcomes.