A characteristic feature of Swedish law is that regulations must be issued by law if they relate to the economic relationships of individuals. This means that contract law may not be formulated by government ordinances and official regulations. However, this does not prevent the courts from determining the legal situation in more detail in their application of the law, which can be done, for example, by interpreting general standards of assessment, introducing certain exceptions to a statutory rule and further developing the law in the absence of statutory rules. The Supreme Court also has a normative power in that its decisions constitute precedents and are important for guiding the application of the law. It is my intention in the project to investigate whether it is possible to create an appropriate division of labor between the legislator and the courts when it comes to the development of contract law, which means that a central question will be to what extent the regulation of contract law should be done through legislation and statutory reasons and to what extent it should be done through precedents. The more the legislator uses general standards of assessment, leaves exceptions to the courts and refrains from legislating on certain aspects of contract law, the more power is given to the courts. The project also aims to examine whether the courts should be guided by a purposive approach to interpretation. The work is an extension of a previous project on a court's competence to deviate from the law in contract law.