All participants in the establishment of bilateral pecuniary contracts are based on the principle of equal value of reciprocal performance, the same is called the principle of equivalence. Applying this principle seeks to achieve the equivalence of the obligations of the contracting parties. It is sought by the contracting parties to regulate their obligations in such a way that what they are obliged to do or to do each other under the contract is equivalent to what they acquire under that contract. Since the foundation of a legal transaction is the basis of the co-operation of the contracting parties, it is more and more common for each party to make the most of its profit. Encouraged by the ability to earn more money, they often make contracts at the damage of the other contracting partie, using his ignorance, difficult material condition, or misleading. That produce a violation of the principle of equal value of performance. For the violation of the principle, an objective circumstance is important, that is, that in a certain compulsory relationship there is a difference between the value of the reciprocal performance through the law determined by the boundary. Civil obligations Act stipulates in which cases a violation of the principle of equal value of the performance occurs and which legal consequences then occur. In particular, the legal consequences of the legality of the legal transaction will arise in the event of the conclusion of the green agreement, then the assassination of the legal work because of excessive damage and the last possibility is termination due to material and legal disadvantages. This principle requires that there is a balance between the contracting parties, in the event of a violation of that balance, the Civil obligations Act contains the rules for re-establishing that balance.