Large parts of social life are significantly supported by non-profit associations and the voluntary engagement of citizens. The number of registered non-profit associations has now risen to over 600,000; more than 60% of all citizens are members of an association. The Volunteer Strengthening Act, enacted on March 21, 2013, legally facilitates and fiscally promotes voluntary engagement. The authors have revised the handbook for the 13th edition largely due to this law. They provide detailed insights into the important changes that have come into effect for associations—regarding the limitation of liability for volunteer board members, other volunteer committee members, and special representatives, as well as 'regular' association members, through the extension of the period for timely use of funds and the E.