Changed circumstances (clause rebus sic stantibus) and new trends in the settlement of this rule

This paper analyzes the concept of the clause rebus sic stantibus and assessment of suitability of its application in comparative legal systems. The author also analyzes how this rule (institute) is treated in the instruments of international treaty law, especially in the Principles of European Contract Law. He concludes that modern life imposes the need of accepting this as a general rule and that the legislation, particularly with regard to a content of its determination, should bear in mind the regulations contained in existing international instruments.