Philipp Alexander Burek examines the doctrinal scope of self-defence where defensive conduct affects not only the individual legal interests of the attacker but also collective interests protected by law. Such collateral damage resulting from self-defence marks a borderline area between self-defence and necessity that has so far remained insufficiently explored. The prevailing dichotomy, according to which self-defence either applies without limitation or must give way entirely, is criticised as inadequate. The central thesis is that self-defence derives its justificatory force solely in relation to the attacker. Interferences with supra-individual legal interests therefore constitute persisting wrongdoing. On this basis, the author develops the concept of a partial justification in self-defence. Methodologically, the study combines doctrinal analysis with historical and teleological interpretation, rejects both the doctrine of the third-party effect of self-defence and recourse to section 34 of the German Criminal Code, and advances a differentiated solution for composite offences under current German criminal law.