The study at micro level about in which way individuals’ micro-motives and behaviors influence on an effective rule of law is a deficit in the literature. The analysis of the microfoundations of the law ´s empire is absent in the field of legal studies. In this way, most explanations presented to elucidate the performance of the rule of law has been presented at macro level, emulating properties of countries, such as wealth (Barro 2000; Joireman 2004), ethnic fragmentation (Hayo and Voigt 2005; Hansson and Olsson 2006), religion (Barro 2000; Hayo and Voigt 2005), British legal or colonial tradition (Blake and Martin 2006; La Porta et al. 1999), or Communist past (Hoff and Stiglitz 2004; Sandholz and Taagapera 2005). Assuming that law, in the sense of a set of formal written documents, will be largely irrelevant if the rules are excessively costly in comparison with other possible mechanisms to process private-private and public-private interactions such as informal institutions or illegal practices (Rose-Ackerman 2004),,in this work I model the game that underlies the well-know corrupt act of “mordida” in Mexico City, that is, bribe-seeking and bribe-offering interactions when a citizen is accused of or commits a transit infringement. The first conclusion of this paper is that corruption is the the dominant strategy of this game. The second conclusion is that specific aspects of the penalty itself in Mexico City (e.g., the car is moved to an often unsafe “corralón” or police impound) are the main factors that make corruption the equillibrium of the “bribe game”.