Given the realities of criminal court development, motions and complaints for the protection of rights play an important role. However, the study of these advocacy tools is an under-researched issue. This requires further consideration, since these mechanisms can be really effective in different situations. The purpose of the study is to determine the importance of attorneys' motions and complaints for the purpose of implementing modern justice. For this Scoping Review, the PRISMA approach was used. Date range for inclusion of scientific literature: 2014-2024 (i.e., the last 10 years). To select the scientific literature, the following search databases were selected: Scopus and Google Scholar. The criteria for including literature were based on 5 items related to content, scientific novelty, methodology, and language. A total of 52 items of scientific literature, legislative acts and reports were included in the study. The results show that different countries use different models of advocacy, however, such tools as motions and complaints are common around the world. The purposes of attorneys' motions and complaints are not based on making a specific decision or performing a specific action, but on the realization of rights and legitimate interests existing in connection with the procedural or real status of a person. The conclusions determine that motions and complaints have an impact on further proceedings in a criminal court; in particular, they may affect the exclusion of inadmissible evidence, disclosure of additional evidence, protection of the rights of the accused, fulfillment of strategic tasks and recording of violations of procedural rights.