This chapter discusses contract law in relation to comparative law. It first considers some of the reasons why contract law has become the classical subject matter of comparative law before explaining the practical relevance of the rules on general contract law to comparative studies. It then examines the similarities and differences between civil law and common law, along with the enforceability of agreements on the basis of the parties’ intention to create legal relations, the ‘doctrine of consideration’, and formal requirements of the contract. The chapter goes on to describe the two processes of ascertaining the content of a contract, namely: interpretation and supplementation. It also looks at illegal, immoral, and unfair contracts as well as the provisions on mistake, claims for performance of contractual obligations, termination of contracts, and claims for damages in case of non-performance or if a party does not perform its obligations properly.