Research on Web credibility assessment can significantly benefit from new models that are better suited for evaluation and study of adversary strategies. Currently employed models lack several important aspects, such as the explicit modeling of Web content properties (e.g. presentation quality), the user economic incentives and assessment capabilities. In this paper, we introduce a new, game-theoretic model of credibility, referred to as the Credibility Game. We perform equilibrium and stability analysis of a simple variant of the game and then study it as a signaling game against naive and expert information consumers. By a generic economic model of the player payoffs, we study, via simulation experiments, more complex variants of the Credibility Game and demonstrate the effect of consumer expertise and of the signal for credibility evaluation on the evolutionary stable strategies of the information producers and consumers.