The aim of this study is to analyze how the public goods game can contribute to the teaching of sustainability and positively influence sustainable behavior. The public goods game was applied to undergraduate students in business administration of educational institutions, with treatments including punishment and reward. It was called the ‘reservoir game,’ once the public good in focus was a reservoir, which ensures the drinking water supply for the city. The possibility of punishment proved ineffective in ensuring the preservation of the public good, as the possibility of reward proved to be efficient. Next, the students participated in focus group sessions. Debates about the posture towards sustainability, the importance of good examples as influencers, of awareness raising activities overlapping the punishments by the lack of cooperation, and the use of reward due to donations for the preservation of the public good were encouraged. The long-term perspective as justification for cooperation represented one of the key learning points. As complementary approach to teaching sustainability, the public goods game encouraged the students’ reflection upon the possibility to cooperate/contribute financially to the preservation of the environment or take advantage of its benefits from the contributions of others.