This fact sheet was written by Nadine Fréry and Béatrice Lamboy based on the CPS Volume 2 guidelines published by Santé publique France. It focuses on the second general psychosocial competency (CPS) and provides a summary of a specific psychosocial competency: Asserting oneself (and resisting social pressure) through assertiveness and refusal (S2.1). Assertiveness involves knowing how to express one’s emotions, needs, and ideas in an appropriate manner (with confidence, accuracy, and respect)—without deferring to others through passivity or social withdrawal, and without imposing one’s point of view and rights through aggression. The ability to refuse requires knowing how to “say no” assertively when faced with someone or something that goes against one’s needs, desires, values, or rights. It is based on several areas of knowledge and skills: Understanding social influence and resisting social pressure; Communicating assertively; Refusing assertively; Knowing how to express and receive constructive criticism. This specific skill can be applied during CPS activities. Thus, following a theoretical segment, practical examples are presented for adults, youth, and children.