It is common for scholars to describe institutions as ‘rules of the game’. This description entails a separation between a society and its rules. Social change thus results as societies amend their framing rules. This article compares the common treatment of institutions as rules against an alternative treatment wherein societies and institutions are images of one another. If there were no rules governing interactions among some set of people, you would have a mass of people but that mass would not constitute what we recognise as society. This simple distinction between institutions as rules by which a society is governed and institutions as society itself creates divergent paths for institutional theory, which this article explores.