This collection of essays, derived from an international workshop, explores the significance of implicit understandings and tacit expectations of the parties to different kinds of contractual agreements, ranging from simple discrete transactions to long-term associational agreements such as those formed in companies. An interdisciplinary and comparative approach is used to investigate how the law comprehends and gives effect to the these implicit dimensions of contracts. The significance of this enquiry is found not only in relation to the interpretation of contracts in many different contexts, but more fundamentally in how social practices involved in making contracts should be analysed and comprehended.