Gamification has been identified as an important means of engagement in environmental sustainability. It has been shown to enable consumers to accept green products and effectively engage in resource recycling and can, therefore, help to accomplish sustainable development of the ecological environment. However, theoretical and practical interest in the research of gamification has been hampered by the lack of a reliable scale with confirmed predictive validity. Thus, this study aims to operationalize, develop, and test a measure of gamification based on a theoretically valid definition. Drawing on data from the literature and six in-depth interviews, this study develops and validates a scale to measure gamification. Via the exploratory factor analysis and confirmatory factor analysis, the results identify nineteen items across six dimensions. To investigate the model extension of the developed multi-dimensional 19-item ESGS, cross-validation analysis is performed using 394 responses obtained through the Zero2 APP. This allows the implementation of a green and sustainable economy through gamified ESG. Finally, based on the research results, this study offers practical implications for governments (i.e., policymakers) and non-governmental organizations (NGOs) seeking to devise strategies to improve sustainable user engagement behavior among citizens.