Self-defence is an act of defending yourself or others against means of harm or in the action of crime prevention. As defined under Section 3 of the Criminal Law Act 1967 it states that ‘a person may use such force as is reasonable in the circumstances in the prevention of crime. Self-defence is also mentioned in the Criminal Justice and Immigration Act 2008. The CJIA Section 76(1) provides that ‘in deciding whether the force used is reasonable, considerations must be taken into account so far as relevant in the circumstances of the case’.

Self-defence is split into two sections, private defence and public defence. Private defence is the act of defending oneself from the threat of harm, also known as Common Law. Public defence is the act of protecting and defending a member of the general public from the threat of harm, also known as Statute Based Law. Self-defence covers the law on making pre-emptive strikes, the necessity of force used and the reasonableness of force. The use of force can be justified in self-defence and the prevention of crime by determining the burden of proof.

In some situations there can be an overlap, where the claimant cannot rely solely on statutory defence. In the situation of a person not being capable of committing a crime – for example underage, or insane then they would have to rely upon the Common Law. The amount of force used in both must be reasonable. In the case of R v Cousins (1982) it was held that both defences are available to an