This chapter outlines SEMPER’s proposals for establishing legal predictability of electronic transactions. An important novelty is a method for assigning liability to digital signatures in a way that is predictable for all sides without requiring prior investment into highly secure hardware, the Commitment and Liability-Cover Service. The proposals also cover most other legal aspects of electronic commerce, again with a focus on predictability even in cross border scenarios, fairness to all parties, and ease of adoption. A model for implementing these proposals is given as the SEMPER Electronic-Commerce Agreement, SECA.