Guglielmo Maglio is Manager of Exhibitions at the science centre “Città della Scienza” of Naples. With “Città della Scienza” he took part in the creation of “Decide”, which he appreciates for its ability to create an informal atmosphere favouring discussion. As concerns the involvement of scientists and policy-makers in the debate, though desirable, it sometimes may influence negatively the spontaneity of the debate among non-experts. In the participants, the main differences can be ascribed to personal experience, rather than to other factors such as age, nationality or social groups. Though not the ideal places for the use of this kind of games, especially owing to time limits, science centres may exploit them to attract specific groups of interest and may obtain useful information on the attitudes of the public to subsequently develop exhibitions and events on the themes dealt with.