The so-called "Prisoner''s Dilemma" is often referred to in business ethics, but probably not well understood. This article has three parts: (1) I claim that models derived from game theory are significant in the field for discussions of prudential ethics and the practical decisions managers make; (2) I discuss using them as a practical pedagogical exercise and some of the lessons generated; (3) more speculatively, I suggest that they are useful in discussions of corporate personhood.