Based on protection motivation theory, this study aims to identify factors that influence the intention to decrease problematic smartphone game use, including the effects of a gaming habit and subjective norms. The research model is tested with a scenario-based survey method. Players' perceived threat refers to the negative consequences (eg, reduced performance or social isolation) that are caused by problematic smartphone game use. The findings indicate that under high fear appeals, threat appraisal creates fearful emotions about suffering from the negative consequences, which further reduces the gaming habit and activates the intention to decrease use. Self-efficacy in decreasing game playing, the response efficacy of decreasing usage in avoiding the threat and subjective norms effectively promote users' intention to decrease use. Moreover, response costs reduce the intention to decrease use. The findings provide insights into how to activate users' intention to decrease problematic use, and the resulting implications are discussed. K E Y W O R D S gaming habit, intention to decrease use, problematic use of smartphone games, protection motivation theory, subjective norms