The purpose of this work is to describe the simulation of trials as a pedagogical tool to develop communication skills for legal argumentation in courses of criminal litigation for undergraduate law students. The methodology of the study is qualitative, research-action-participation (LAP) in legal contexts for the study of a case with university students. The results reveal the importance of combining real case studies with solving related problems and simulating case trials in the pedagogy of legal argumentation. The results also underscore some possible problems that may arise in real life trials, and show the usefulness of role-taking and adopting the second-person standpoint (i.e. the perspective of the other) to resolve issues that emerge in the application of the criminal law. We conclude by showing the importance of developing communicative competences for legal argumentation in oral criminal litigation, for which expert-novice feedback, as well as feedback from other law students, play a fundamental role.