This course puts the existing national and international solutions in a comparative perspective so as to work with the sources of such generally accepted principles. Special attention is given to the UNIDROIT Principles on International Commercial Contracts and the European Principles of Contract Law. It will discuss the general principles underpinning international contracts: contractual formation and negotiations, interpretation, transversal general principles, changed circumstances and hardship, agency, third parties, assignment, self-help and set-off. The course will also discuss the international contract practice and its interaction with the various applicable sources assessing the role of each factor influencing the contract (i.e. contractual regulation, national law and transnational sources) identifying the relevant legal problems of international contracts and the proposed solutions.