- Robert MerkinRobert MerkinProfessor of Commercial Law Exeter Law School, University of Exeter
- and Séverine SaintierSéverine SaintierAssociate Professor in Commercial Law Exeter Law School, University of Exeter
The Casebook series provides a comprehensive selection of case law that addresses all aspects of the subject encountered on undergraduate courses. A contract is a legally enforceable agreement. This chapter explains how the existence of an agreement is determined. After considering how the courts assess whether an agreement has been, using subjective and objective methods, it discusses the precise criteria used to determine agreement, namely offer and acceptance. The chapter defines offers and distinguishes them from invitations to treat. It focuses on identifying acceptances and distinguishing acceptances from responses which are not a mirror image of the offer, such as counter-offers. Much emphasis is placed on explaining the communication principles applicable to acceptances—postal and instantaneous communications, including email. The chapter explains revocations of offers and the communication principles applicable to revocations. It also distinguishes bilateral and unilateral contracts and the special principles applicable to unilateral contracts.