Effective counteraction to the abuse of the right in the legal process is impossible without understanding the causes and conditions of the forms of abuse of the right encountered in practice, which are the ways of its external expression. Consideration of the doctrine and judicial practice of civil, arbitration, administrative, criminal procedure through the prism of the adversarial principle, characteristic of all the types of legal process presented, contributed to the identification of general patterns that cause the abuse of procedural right. In the course of the study, the author examined the forms of abuse of the right (discretionary powers) associated with the implementation of evidentiary activities of the parties to the proceedings, excessive appeals against the actions of the parties, numerous filings of applications, motions, and challenges. The author concludes that the cause of this negative phenomenon is the desire of a person to satisfy his interests, aspirations, emotions in an illegal way. Conditions for the abuse of procedural law arising from the costs of the adversarial principle include a vulgar interpretation of the adversarial principle, a conflict of interests of the parties to the process, subjectivism of a law enforcement officer, his condoning attitude to the presence of abuse of the right. An opponent’s unintentional provocation can cause the abuse of the right in some situations.