"One word leads to another" - interpersonal communication follows certain rules. Those who understand these mechanisms can not only achieve their own conversational goals more effectively but also understand others more easily and interact with them more successfully. It is no coincidence that communication skills are among the most sought-after soft skills in both professional and everyday life. This introduction to the theory and practice of communication explains the principles of effective communication using the film "12 Angry Men" - still a classic for illustrating group dynamics and role behavior. The textbook elucidates the phenomenon of communication through various social psychological studies, theories, examples, and perspectives, encourages expanded reflection on the topic, and provides concrete tips and exercises to enhance one’s own communication.