The state of reinsurance contract law as unregulated has continued to this day. One of the reasons for reluctance in adopting particular legislation for reinsurance contracts lies in the fact that it is a legal job between professionals − two legal entities who have adequate professional knowledge and who do not need a specific legal framework to regulate their legal relationship. However, after the outbreak of the World Financial Crisis at the end of 2007, it became apparent that the financial sector had to submit to stricter rules on risk management and providing sufficient capital to cover them, unless possibleotherwise. In this regard, an initiative for formulation of the appropriate reinsurance contract law at supranational level was launched in 2015. The first version of the Principle of Contract Reinsurance Law published in November 2019 is the subject of attention in this paper. In this paper, the authors investigate the content and effect of the provisions of these Rules, but do not analyze in more detail relevant provisions of the Rules of International Trade Agreements of the International Institute for the Unification of Private Law of 2016, which apply supplementary to the reinsurance contract law. In this research, the authors primarily considered the aforementioned solutions and their effect on the rights and obligations of the reinsurer and the reinsured, with reference to the views of legal reinsurance theory.