The adoption of open data policy-making by governments is limited due to different types of constraints. Civil servants are reluctant to open their data to the public for many reasons. The lack of knowledge of benefits that can be produced by the release of data and the overestimation of risks and operational complexity seems to decrease their willingness to support the opening of data. The idea that a serious game intervention can change awareness of participants in different domains is already known. Yet, games are domain dependent and concepts differ per domain. A game has never been used for the emerging domain of open data in which civil servants are operating in a bureaucratic environment having a risk-averse culture and strict institutional rules. A role-playing game prototype was designed for civil servants to experience open data policy-making. This paper analyses its first results aiming at changes of perception for the participants of the game and aims to understand the changes in behavior of civil servants that played it. For some participants, the game influenced their attitude, whereas others were not influenced. Suggesting that different approaches might be necessary for changing the attitude of different groups.