This short article (for a symposium on joint ventures) provides practitioners and law professor with a 20 question checklist to guide the competitive effects analysis of the formation of a joint venture and the specific restraints and conduct of the venture. The questions mainly focus on ventures among actual or potential competitors, though some of the questions also are relevant for ventures involving complementary product firms. The questions concern potential competitive harms, potential competitive benefits, and the determination of net competitive effects. While this sequencing follows the standard burden-shifting formulation of the rule of reason decision process, the article notes that this sequencing should not be approached rigidly. A finding of a lack of efficiency benefits might suggest that the motivation of the JV is to achieve and exercise market power to the detriment of consumers, thereby supporting an inference of harm. Moreover, under a quick look to condemn standard, efficiency benefits are examined first, albeit with a possibly lower burden of proof placed on the venture to justify its formation and restraints.