The contra proferentem rule: Contract law’s great survivor

The contra proferentem rule has been under sustained attack in recent years, as judges doubt whether it has any role to play in modern commercial contract law. This article sheds light on the function of the rule by examining its historical development. The rule has been part of English contract law for over 600 years, playing very different roles at each stage of its development. Lawyers since the medieval period have criticised the rule, but have succeeded in continually repurposing it to fit with new conceptions of contract law and to address the most pressing concerns of their day. This article shows that the contra proferentem rule can provide a fascinating case study in the development of common law doctrine, and argues that the future need not be wholly bleak for one of our longest-lived canons of construction.