During our YOUNG EUROPEAN LEADERS project, students from leadership groups attended the international Žilina Model United Nations simulation, consisting of committees in English, Spanish and French language. This activity is the most intensive practice of theoretical leadership skills developed in the clubs because the students have to face extremely complex issues, follow a specific diplomatic agenda, take part in discussions in a foreign language, be able to use public speeches as a working tool, get expert knowledge of different policies of different states and negotiate to create an effective diplomatic document (solution), supervised by experienced university or high school expert students.