Is there a right to self-defence of a person in danger versus omission ? Even though self-defence is a central reason for justification in criminal law, until now explanations are almost solely about the right to self-defence against active actions. In contrast, this dissertation deals in a systematic way with all questions about the lawfulness of self-defence versus omission. Firstly, the author analyses under which circumstances omission is a present and unlawful attack. Here it is pointed out that justifying a criminal act by the right of self-defence is only possible in the case that the desisting person is responsible for effecting imminent danger to the object protected by the right of self-defence. Afterwards, the question is discussed, how a necessary and demanded defence versus an omission attack can look like. In doing so a critical examination concerning the problem of justifying self-defence torture is presented.