European legal systems have long encompassed the concept of the “general clause”, particularly in contract and labor law. The general clause includes unwritten legal norms such as good faith and public morality, and these principles are duly incorporated in the process of construing civil and labor contracts. While the general clause itself is formally absent in common law systems, its principles have found their way into modern British and American law. Two primary examples include the doctrines of good faith and unconscionability. In a broader sense, the idea of introducing rather indeterminate legal norms to be construed and interpreted by judges appears to be well-suited to a common law system. However, as applied to American labor law, the very indeterminacy of these terms has had rather negative effects on the rights of employees and the labor unions that represent them. Specifically, this article examines the good faith requirement in collective bargaining under the National Labor Relations Act (NLRA) and the doctrine of unconscionability in employment arbitration agreements, and concludes that they both should be supplemented by more definite standards in order to effectively protect employees.