The law may provide for circumstances in which the creditor's rights are transferred to another person. In particular, the rights of the creditor under the obligation are transferred to another person on the basis of the law by a court decision on the transfer of rights, if the possibility of such transfer is excluded from the law.

Using formal, logical and systematic research methods, the author examines in detail the cases of a court ruling on the transfer of the creditor's rights to another person, including when exercising pre-emptive authority to acquire property and when fulfilling a voluntary obligation to cede the right. At the same time, it proves that the studied translation of law relates to the administration of justice in a pre-contractual dispute, notable for the fact that the will of the parties is considered to be committed only in the presence of a judicial act. The court's decision is endowed with the qualities of an element of the legal composition that gives rise to the desired legal consequences, namely, an external change in the obligation.

The so-called «constitutive theory» of the exercise of preemptive right has been criticized. According to the author, this theory does not take into account that the violated preemptive power is protected by one of two transformative lawsuits – on compulsion to renounce the contract (compulsory succession) or on compulsory redemption of property rights. The court's decision on the first claim leads to an external change in the obligation, since the second is brought in the event of termination of the contract under which the property right was acquired, forcibly redeemed under another contract.

According to the results of the study, it was concluded that the norm of subclause 2 of clause 1 of Article 387 of the Civil Code of the Russian Federation is designed for two groups of cases of singular succession: 1) the court makes a decision on the claim for the fulfillment of the obligation arising from the law to conclude an agreement on the assignment of rights; 2) the court's decision by virtue of the law is necessary for the fulfillment of a voluntarily accepted obligation to assign the right. In these cases, the court decision produces a transformative effect, being an element of the legal composition, entailing an external change in the legal relationship.