In the first funding phase of this project (07/2013-08/2014) we conducted a process and effectiveness evaluation of anti-violence trainings the Berlin police offers to schools in Berlin. The aim of the second funding phase of the project (01/2015-12/2015) is to develop a training manual based on the outcomes of the evaluation, which can be used by organizations in order to teach situation-specific attitudes and skills of adolescents to cope with conflict situations. The students are supposed to learn how to solve these situations in a constructive way, i.e., without acting aggressively or violently. The manual serves as a conceptual basis and will include specific exercises, which can be adapted to different institutional contexts, age groups, and problem groups. In a third stage of funding (01/2016-12/2016) the applicability of the manual in school settings will be tested by the Berlin police, whose prevention representatives are trained by us. In this way, the training's effectiveness will be based on empirical evidence.