This paper presents a study about a ‘serious game’, “Energy Battle”, as a means to influence energy-related behavior in households. The Energy Battle is designed to engage home occupants in a fun way in energy conservation via a competition with other households. The challenge enabled home occupants to gain insight in their energy consumption and actively involved them in reducing energy consumption. The energy reduction was registered online and information and tips on the online platform were given to help the participants to reduce energy consumption. The game is tested in 20 student-households in the city of Rotterdam. The evaluation of the pilot focused on behavioral changes in the short and in the long term and on the role of social interaction in the game. The Energy Battle in the Rotterdam households resulted in an average reduction of 24% in electricity consumption. Eight months later the participants indicated that only a few of the behaviors developed in the game were maintained. In interviews and questionnaires the participants indicated that the game made them more aware of energy consumption in their household and how to influence it. Additionally it affected social aspects, such as dining together to save energy and the ability to discuss a topic that otherwise was avoided. Based on the results of the first study a second study is being set up with families to gain deeper insight in the effect of the social interaction in the game on behavior change in the short and in the long term.