As a side event to the conference "Game Theory, Experience, Rationality", the Institute for System Simulation of Socio-economic Processes (SYSIS) organized a computer tournament. It was based on the well-known game-theoretical model "Tragedy of the Commons". This model — in many respects similar to the even more famous "Prisoners' Dilemma" — illustrates the instability of "good" equilibria in games, where each player can gain by deviating from the cooperative strategy.