Gamification, the introduction of game elements to non-game contexts, is increasingly proposed as an effective tool to attract and facilitate stakeholder attention and engagement. A growing number of conceptual and empirical research on gamification generally report positive effects of gamified communication. In the following, we ask whether gamification is able to extend mere marketing to communicate matters of social and environmental concern. Based on several experimental studies, we show that there are boundary conditions to the effectiveness of gamified sustainability communication on stakeholder attitude, intention, and behavior. We find positive, negative and insignificant effects of gamification on pro-environmental attitude, intention, and behavior. We conclude with a call for more rigorous forms of experimental manipulation in gamification research, and highlight the influence of methodological choices on study outcomes, as well as develop future research opportunities.