This dissertation consists of three journal articles that explored the effectiveness of a digital game, called EnerCities, in producing pro-environmental attitudes and behaviors by using a mixed-methods study approach. The first study was conducted as a quasi-experimental study among undergraduate students in the United States. Based on the Attitudinal Learning Instrument (ALI), this study found that the attitudinal learning gained from EnerCities influenced participants’ pro-environmental behavioral intentions significantly. This learning was retained until five weeks after game play according to the qualitative results of the study. The second study, conducted in India, used EnerCities to study the differences in attitudinal learning among high school students who played the game collaboratively or individually, using the ALI and Theory of Planned Behavior (TPB). Results showed that the attitudinal learning and its effect on pro-environmental behavioral intentions between collaborative and individual players was similar. This study also showed that EnerCities had significantly impacted the environmental attitudes and behaviors of the game players when compared to students who did not play any game, although all students had studied environmental studies through traditional instructional methods since elementary school. The third study, conducted among high school students in India, compared the environmental attitudes between game players and students who did not play any game based on the New Ecological Paradigm (NEP) scale. Both the unidimensional and multi-dimensional properties of the NEP were considered. It was found that EnerCities had impacted game players’ environmental attitudes significantly. All the three studies showed that digital games are more effective in promoting attitudinal (cognitive, affective, behavioral and social) learning compared to traditional instructional methods. This supports the implementation of digital games as a pedagogical tool in influencing environmental attitudes and behaviors.