We address the problem of collecting a database of "common-sense facts" using a computer game. Informally, a common-sense fact is a true statement about the world that is known to most humans: "milk is white," "touching hot metal hurts," etc. Several efforts have been devoted to collecting common-sense knowledge for the purpose of making computer programs more intelligent. Such efforts, however, have not succeeded in amassing enough data because the manual process of entering these facts is tedious. We therefore introduce Verbosity, a novel interactive system in the form of an enjoyable game. People play Verbosity because it is fun, and as a side effect of them playing, we collect accurate common-sense knowledge. Verbosity is an example of a game that not only brings people together for leisure, but also collects useful data for computer science. Author Keywords Distributed knowledge acquisition, Web-based games, common-sense reasoning. ACM Classification...