The presented diploma thesis deals with the concepts of self-defence and necessity and their position as legal institutions within the framework of the Czech criminal law, as well as the consequences of the transgression of their limits as defined by the legislation. Both self-defence and necessity are categorised among the circumstances precluding lia- bility and share the essence of creating a legal scope under which the regular addressees of the legal norms are allowed to defend their own interests or interests of the society as a whole, provided that the interests in question are themselves protected by the legal system. Such defence is generally permissible in the situations of immediate unavailabi- lity of an intervention from the sid...