This volume contains sixteen original articles documenting recent progress in understanding strategic behaviour. In their variety they reflect an entire spectrum of coexisting approaches: from orthodox game theory via behavioral game theory, bounded rationality and economic psychology to experimental economics. There are plenty of new models and insights but the book also illustrates the boundaries of what we know today and explains the frontiers of tomorrow. The articles were written in honour of Werner Güth. Contents Boundedly Rational Qualitative Reasoning in Comparative Statics; R.Selten Complexity Constraints and Adaptive Learning: An Example; T.Börgers & A.J.Morales Vengefulness Evolves in Small Groups; D.Friedman & N.Singh Network Formation and Coordination Games; S.K.Berninghaus & B.Vogt Specific Skills, Imperfect Information and Job Rationing; H.Bester Testing Game Theory; J.Weibull A Dialogue Concerning the Nature of Rationality; H. Kliemt & Axel Ockenfels Behavioral Game Theory: Thinking, Learning, and Teaching; C. F.Camerer, T-H.Ho & J.Kuan Chong Double Auction Markets with Stochastic Supply and Demand Schedules: Call Markets and Continuous Auction Trading Mechanisms; J.H.Kagel Multistage Sealed-bid K-double Auctions: An Experimental Study of Bilateral Bargaining; J.E.Parco, A.Rapoport, D. A.Seale, W.E.Stein & R.Zwick The Role of Arbitration in Bargaining; G.E.Bolton & E.Katok Communication and Cooperation in a Common-Pool Resource Dilemma: A Field Experiment; J-C.Cardenas, T.K.Ahn & E.Ostrom Price Competition: The Role of Gender and Education; M.Dufwenberg, U.Gneezy & A.Rustichini Parity, Sympathy, and Reciprocity; W.Güth & M.E.Yaari Fairness and Greed in Stackelberg Games; S.Huck, M.Königstein & W.Müller Learning from (and in) the Ultimatum Game: An Interview with Alvin E. Roth; S.Huck