Strategic actors often require a great deal of informational and computational resources to calculate game-theoretic equilibria, and scholars need a precise accounting of incentives in order to model the decisions faced by these actors. Rarely are both of these conditions—player rationality and payoff quantifiability—met when scholars attempt to model the behavior of individual actors in the law (especially the behavior of lay people such as jurors, litigants, or criminals). Behavioral economists have proposed posthoc adjustments to account for the failure of player rationality, but these adjustments—if they are indeed correct—make the pursuit of equilibrium impossible for any actor with realistic informational and cognitive resources. This Article discusses the necessary conditions for the emergence of equilibrium strategies, and identifies examples of legal scholarship in which the use of equilibrium solution concepts is problematic because of the improbability that these conditions are met.

In reviewing a game theory text almost twenty years ago, Ian Ayres complained that “countless” law review articles “rearticulate the Prisoner’s Dilemma, but few even proceed” to the simplest of other games. Several years later, in what is still the most significant book treatment of game theory for law, Douglas Baird, Robert Gertner, and Randal Picker began by lamenting how legal scholars had neglected game theory up to that point “other than to invoke a simple game such as the prisoner’s dilemma as a metaphor for a collective action problem.” All of these scholars asserted the great value of game theory to legal analysis and the hope that it would transform legal theory as it has transformed economic theory.