This book guides the reader through the basics of Swiss association law and decision-making, legal consequences and effects for improper decision-making related thereto. It illustrates the legal remedies available for incorrect decision-making (in particular, the actions of voidance and for declaration of nullity of a resolution of an association that infringes the law or the statutes). Nullity and voidability relate to the issue of the validity of a decision; both have the function of a sanction, having the aim of forcing sports governing bodies to comply with the rules set by statutes and law. A special focus is given to questions relating to the appeal procedure at the Court of Arbitration for Sport and arbitration in Switzerland in general.