This textbook raises awareness of the importance of "biographical case understanding" in individual case assistance and introduces concrete methods and work techniques based on reconstructive principles. The authors connect two methodological development strands in social work: the development of individual case assistance starting from the classical three-step approach and the development of a qualitatively reconstructive paradigm of case work. The integration of these two methodological strands is illustrated through case stories from various fields of individual case assistance, which were collected using the method of narrative-biographical interviews.