The number of HIV-positive people in the Czech Republic has trebled over the last decade. An educational programme aimed at the prevention of HIV and STDs in adolescents between 13 and 19 years of age is underway in the Moravian-Silesian Region in the Czech Republic. All schools in the region have been offered the chance to participate in the programme (on a voluntary basis). The programme consists of an educational lecture and a game with interactive elements; the students perform various tasks in groups. An anonymous paired questionnaire (input/output) was used to assess the efficacy of the programme. In order to evaluate the programme efficacy, descriptive statistics, non-parametric Wilcoxon paired test at the level of significance of 5%...