This paper revisits the question of substantive rules versus procedural rules to enforce constitutions. Scholars engaging in positive analysis of constitutional rules argue that procedural rules are more durable and act as better safeguards for constitutional maintenance. Chapter 61 of the Magna Carta, also known as the ‘security clause,’ lays out the procedural component for enforcement of the Charter. The clause provides for a council of twenty-five barons to enforce the Charter, with provisions to choose and replace the members, outline their powers, and constrain executive action. It is therefore puzzling that Chapter 61 is absent in the 1216 issue of the Magna Carta, and all reissues thereafter. On the other hand, substantive protections like Chapter 40 have been maintained through the evolution of constitutional rules over 800 years. It is even more puzzling that the Magna Carta survived for 800 years without the main clause to enforce it. This paper argues that the procedural-versus-substantive distinction is superficial, and instead focuses on polycentric arrangements, to understand constitutional maintenance and provide an explanation for the failure of the 1215 Charter and the longevity of the reissues of the Charter.