In this talk, I will be presenting two novel approaches to understanding interaction in games followed by a conjecture that has been open for three years now. Inspired by the name of Marseille Interaction Seminar, I will keep technical details at minimum and instead focus on the various applications and playing actual games in the seminar room. So please don’t forget to bring pen and paper with you! First, I will briefly introduce the optimin criterion, which addresses weaknesses of Rawls’ maximin criterion. Optimin criterion suggests “optimizing” the minimum for optimistically pessimist individuals. The optimin principle not only coincides with the equilibria in zero-sum games, but it also generalizes stable matchings in one- and two-sided matching models, and competitive economic equilibrium in the Arrow-Debreu economy. Second, I will endow players with a “free will” so that they are completely free to cooperate or act independently in extensive form games. Accordingly, I will describe how players would rationally play such games based on a combination of backward and forward induction reasoning.