Abstract: Competition law's prohibition on price fixing and related horizontal agreements is one of its few uncontroversial provisions and is understood to be well grounded in economic principles that are taken to provide the foundation for competition policy. Upon examination, however, commonly offered views of the law's conception of agreement prove to be difficult to articulate in an operational manner, at odds with key aspects of legal doctrine and practice, and unrelated to core elements of modern oligopoly theory. This Article explores these and other features of the agreement requirement and suggests the need for a wholesale rethinking of how competition law should approach the oligopoly problem.