CRIMES ACT 1900 - SECT 418 Self-defence-when available 418 Self-defence-when available

(1) A person is not criminally responsible for an offence if the person carries out the conduct constituting the offence in self-defence.

(2) A person carries out conduct in self-defence if and only if the person believes the conduct is necessary:

(a) to defend himself or herself or another person, or

(b) to prevent or terminate the unlawful deprivation of his or her liberty or the liberty of another person, or

(c) to protect property from unlawful taking, destruction, damage or interference, or

(d) to prevent criminal trespass to any land or premises or to remove a person committing any such criminal trespass,

and the conduct is a reasonable response in the circumstances as he or she perceives them.

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  CRIMES ACT 1900 - SECT 421

Self-defence-excessive force that inflicts death

421 Self-defence-excessive force that inflicts death

(1) This section applies if:

(a) the person uses force that involves the infliction of death, and

(b) the conduct is not a reasonable response in the circumstances as he or she perceives them,

but the person believes the conduct is necessary:

(c) to defend himself or herself or another person, or

(d) to prevent or terminate the unlawful deprivation of his or her liberty or the liberty of another person.

(2) The person is not criminally responsible for murder but, on a trial for murder, the person is to be found guilty of manslaughter if the person is otherwise criminally responsible for manslaughter.

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Both from the Crimes Act 1900 NSW.