Self defence law NSW Australia

Call Our National Legal Hotline

1300 038 223
Open 7am - Midnight, 7 days
Or have our lawyers call you:

This article was written by Cara Maynard - Senior Associate – Canberra

Before joining the team at Armstrong Legal, Cara worked as a DNA expert preparing and giving DNA evidence in criminal trials. In this role she liaised with police, DPP and defence practitioner regarding a variety of matters including DNA transfer, deposition and recovery. Cara has reviewed and interpreted thousands of DNA profiles that were reported as intelligence to the NSW...

The Defence of Self-Defence

Self-defence is a legal concept that can render otherwise unlawful conduct lawful if it can be demonstrated to the necessary standard that the conduct was done in self-defence. This article outlines the operation of the defence of self-defence in New South Wales.

An example of self-defence

A person is involved in a verbal argument with a friend. The friend steps into their personal space and raises a fist in their face. The person is fearful that they may be struck and shoves them away. They fall back a step and claim that the person has assaulted them.

In this scenario, whilst the friend did not physically harm the person, their conduct did put the person in fear of immediate and unlawful violence. Accordingly, should the person be charged with assaulting their friend, they may rely on the defence of self-defence. If the court is satisfied that the person was acting in self-defence, they will not be found guilty.


Section 418 of the Crimes Act 1900 outlines when self-defence is available and requires that the accused:

  1. Believed their conduct was necessary to:
  2. Defend themselves or another person; or
  3. Prevent or terminate the unlawful deprivation of their liberty or the liberty of another person; or
  4. Protect property from unlawful taking, destruction, damage or interference; or
  5. Prevent criminal trespass to any land or premises or to remove a person committing any such criminal trespass; AND
  6. The conduct is a reasonable response in the circumstances as they perceived them.

This is known as the ‘two-limb test’ for self-defence.

In considering the first limb, the finder of fact (the magistrate, judge or jury depending on which court the matter is heard in) needs to consider the subjective circumstances of the accused. For example, their age, gender, health, mental health or relevant experiences (for example whether they have previously been a victim of violence).

It is not relevant to the determination of self-defence if the accused had reasonable grounds to believe their conduct was necessary, only that their belief was genuinely held. If the finder of fact is satisfied there is a reasonable possibility that the accused believed their conduct was necessary the first limb is made out, and they then must consider whether the second limb is made out.

In satisfying themselves of the second limb, the finder of fact must consider whether the conduct was a reasonable response in the circumstances as the accused perceived them. This involves some measure of objective assessment in respect of what was reasonable. For example, would the finder of fact consider it reasonable that the accused stabbed another person in circumstances where the accused believed that the other person was going to smash an item of property belonging to the accused and worth $5. It is unlikely that the finder of fact would find the conduct reasonable, even if satisfied that the accused genuinely believed their property was going to be damaged.

However, the objective determination of whether a response was reasonable must be applied through the lens of what the accused perceived at the relevant time.

Onus Of Proof When Raising Self-Defence

When a person is charged with an offence and wants to rely on self-defence, they or their legal representative bears the burden of raising self-defence on the ‘balance of probabilities’. This means that the finder of fact must be satisfied that it is more likely than not that the person was acting in self-defence.

Once self-defence has been successfully raised, the burden then shifts back to the prosecution to negate self-defence. To do this the prosecution must prove beyond a reasonable doubt that either:

  1. The accused did not genuinely believe that their conduct was necessary; OR
  2. The conduct was not a reasonable response to the circumstances as the accused perceived them.

The prosecution is required to negate only one of the two limbs of self-defence beyond a reasonable doubt, for self-defence to be defeated.

When is Self-Defence Not Available?

Under section 420, the defence of self-defence is not available if the accused applies physical force that results, either intentionally or recklessly, in death and the conduct was done to protect property or to prevent criminal trespass.

Excessive self-defence

Under section 421, where the accused used force that involved the infliction of death and the conduct was not a reasonable response to the circumstances as the accused perceived them but the accused believed their conduct was necessary to protect:

    1. Themselves or another; or
    2. To prevent/terminate the unlawful deprivation of their liberty, or the liberty of another;

the accused may be found not guilty of murder, and instead found guilty of manslaughter.

What If The Accused Was Intoxicated?

Where a person is charged with an offence and wishes to rely on self-defence, their state of intoxication is relevant to the first limb of the defence, (ie that they believed their conduct was necessary). However, the state of the accused’s intoxication is not relevant to the assessment of whether their conduct was reasonable in the circumstances as they perceived them.

If you require legal advice or representation in any legal matter, please contact Armstrong Legal.

Armstrong Legal
Social Rating
Based on 381 reviews
Legal Hotline
Open 7am - Midnight, 7 Days
Call1300 038 223