Chapter 5
Self-defence in New Zealand

The theory of self-defence

5.3Self-defence represents a balance between the needs of an ordered society (in which people are generally not permitted to use force and “take the law into their own hands”) and the right of individuals to ensure their own protection where the state cannot.371
5.4While the exact formulations of self-defence vary in different jurisdictions, the theoretical underpinnings of the defence are similar. There is a fundamental requirement of “necessity” to exert the level of defensive force used.372 As one commentator puts it:373

Society holds life to be sacred, abhors the killing of human beings, and considers premeditated killing among the most offensive of crimes. However, killing may be justified if it is necessary to prevent an act that is as or more offensive than the killing. The law of self-defence therefore justifies killings that are necessary to defend oneself from death or serious bodily injury.

5.5As noted in Chapter 3, self-defence is what is called a “justification-based” defence. It means that any person who successfully claims self-defence was morally justified, and blameless, for acting as he or she did. It is an exception to the criminality of the act.

371Law Reform Commission of Ireland Defences in Criminal Law (LRC 95, 2009) at 26. See also Leason v Attorney-General [2013] NZCA 509, [2014] 2 NZLR 224 at [64].
372R v Wang [1990] 2 NZLR 529 (CA) at 539; and Boaz Sangero Self-Defence in Criminal Law (Hart Publishing, Portland, 2006) at 3.
373Nan Seuffert “Battered Women and Self-Defence” (1997) 17 NZULR 292 at 298.