The article provides a detailed description of the diagnostic game system PLines, which was previously described in the journal, discusses the features of conducting research in individual and pair modes, objective indicators of player activity, the use of which, together with the recording of a number of indicators of universal learning activities (ECD): the ability to plan, analyze and reflect, allows you to study more deeply the structure of game behavior and its relationship with personal qualities that are inaccessible to direct observation. The functional components of the system are described, and the methods of storing, extracting, and analyzing the results of experiments are described.