Running a competition for automated theorem proving (ATP) systems is a difficult and arguable venture. However, the potential benefits of such an event by far outweigh the controversial aspects. The motivations for running the CADE-13 ATP System Competition were to contribute to the evaluation of ATP systems, to stimulate ATP research and system development, and to expose ATP systems to researchers both within and outside the ATP community. This article identifies and discusses the issues that determine the nature of such a competition. Choices and motivated decisions for the CADE-13 competition, with respect to the issues, are given.