The first and paramount task of international commercial contracts is organizing the relationship between the parties in an optimal manner. This means that contracts must determine the rights and duties of the parties so that the transaction works smoothly and its costs can be minimized. A second important task is providing remedies for cases of breach of contract. Requirements as to the rules for such contracts, as well as to the contracts themselves, have to be assessed in light of these aims. The attainment of the first goal is mainly a task of the parties in drafting their individual contracts, but nevertheless may be supported by the applicable rules, as the Unidroit, Principles do in Chapter 6, Section 1. Though the parties to a contract very often deal with the consequences of breaches of contract as well, they rely more often on the applicable rules. It is easier for parties to organize their relationship than to deal with its destruction. An approach that focuses on the distribution of the obligations on the one hand, and the nonperformance on the other hand, is a rather static one. It may suffice if short term contracts are at stake with a rather easy structure where non-money performances are exchanged against money. In international trade which is the subject of the Principles, many contracts are of a more complicated structure, and even if they are not long term contracts they exist frequently over a substantive period. A contract is not only a momentary picture of the reality as it is to according to that very contract, but it also initiates and covers processes which develop in the future. Depending on the subject of the contract these processes may extend over a period of several years and in certain cases even over a legally unlimited period. Insofar as the contract has to reflect the developing reality the Unidroit Principles have to address these problems. Two concepts will be presented here, showing how the Principles tries to cope with them. Hardship, which is mainly directed at the adaptation of the contract, will be analyzed first and more in detail. The second concept, namely force majeure, is primarily di-