Self-Defence Laws in South Australia: Section 15 and the Home Invasion Exception

In South Australia, self-defence is a complete defence under section 15 of the Criminal Law Consolidation Act 1935 if the defendant genuinely believed their conduct was necessary and reasonable and, in the circumstances they genuinely believed to exist, it was reasonably proportionate to the threat, with separate provisions covering property, home invasion, family violence and intoxication.

The Test Under Section 15

Section 15(1) sets a two-part test. First, the defendant must have genuinely, subjectively believed their conduct was necessary and reasonable for a defensive purpose. Second, the conduct itself must have been, in the circumstances as the defendant genuinely believed them to be, reasonably proportionate to the threat they genuinely believed existed. Both limbs are judged against the defendant's own believed circumstances, not against what a court later decides actually happened.

Section 15(3) defines a defensive purpose as self-defence, the defence of another person, or preventing or ending an unlawful imprisonment. Section 15(4) adds that resisting a lawful arrest does not count as a defensive purpose unless the defendant genuinely and reasonably believed the other person was acting unlawfully.

If the belief limb is satisfied but the proportionality limb is not, section 15(2) provides a partial defence to a murder charge, reducing the offence to manslaughter rather than leaving the defendant with no defence at all. This is South Australia's version of excessive self-defence, and it is one of the more generous versions in the country: it exists for both the section 15 personal defence and, separately, the section 15A property defence below.

Who Has to Prove What

Section 15(5) puts the burden on the prosecution. Once a defendant raises self-defence, South Australian law treats the defence as established unless the prosecution disproves it beyond reasonable doubt. This dossier did not locate a South Australian bench book addressing how courts weigh a defendant's ability to retreat within that test, so that layer is not covered here.

Defending Your Property

Section 15A gives a separate, parallel structure for property. The complete defence under section 15A(1) applies where the defendant genuinely believed the conduct was necessary and reasonable to protect property or prevent a trespass, and the response was proportionate. Critically, that complete defence carries an absolute bar: it is not available at all where the conduct caused death and the defendant intended to cause death or was reckless about the risk, regardless of how the proportionality question would otherwise come out.

Section 15A(2) mirrors section 15(2): where the belief limb is met but proportionality fails, and death was not intended or recklessly risked, a partial defence reduces murder to manslaughter. Read together, sections 15 and 15A confirm South Australia does not allow lethal force for property alone.

Home Invasion: Section 15C

South Australia's real home invasion provision is section 15C, titled to remove the requirement of reasonable proportionality where an innocent defence is raised against a home invasion. It applies where the defendant genuinely believed the other person was committing, or had just committed, a home invasion, defined as a serious criminal trespass in a place of residence. It does not apply to a defendant who was themselves engaged in criminal misconduct that gave rise to the threat, and it excludes an on-duty police officer as a home invader for these purposes.

Section 15C removes the objective proportionality requirement, not the subjective belief requirement, and it reverses the ordinary onus: the defendant must establish the conditions on the balance of probabilities rather than the prosecution disproving them. It was inserted in 2003 by the Criminal Law Consolidation (Self Defence) Amendment Act 2003 (No 28 of 2003), which inserted both section 15B and section 15C in the same amendment. Section 15B kept a general proportionality statement, and only later, in 2021, picked up the family violence content described below; section 15C has not been amended since 2003.

Family Violence

Section 15B(2) and (3) direct a court, when assessing belief and proportionality in a case arising out of family violence, to have regard to any evidence of family violence that is admitted. This provision has only applied since 29 March 2021, when it was inserted by the Statutes Amendment (Abolition of Defence of Provocation and Related Matters) Act 2020 (No 43 of 2020). It is an evidentiary direction layered onto the existing section 15 test, not a separate defence, and it sits alongside civil protection order options; see AVO laws in Australia for that separate track.

Intoxication

A 2025 amendment (Act No 31 of 2025), effective 1 September 2025, threaded an intoxication regime through three places rather than creating one standalone section. Under sections 15(2a) and 15A(2a), the partial excessive-force defences are unavailable if the prosecution proves beyond reasonable doubt that the defendant's genuine belief was substantially affected by voluntary non-therapeutic drug consumption; the complete defences under sections 15(1) and 15A(1) are not touched by this rule. Section 15C(2)(c) runs the opposite direction: a defendant relying on the home invasion exception must affirmatively prove, on the balance of probabilities, that they were not substantially affected by such drug use.

Retreat

No statutory retreat requirement was found anywhere in the self-defence provisions. Whether South Australian courts treat a defendant's ability to retreat as relevant to genuineness or proportionality, despite there being no formal duty, was not confirmed against case law or a bench book equivalent to those used in some other states.

Weapons and Self-Defence Items

Carrying an item for self-defence is a separate question from the defence covered on this page, since sections 15 to 15F govern a defence once someone is charged, not a weapons-possession offence. South Australia classifies restricted self-defence items under its own dangerous article scheme, and its status is not fully settled for items like capsicum spray. See self-defence weapons in Australia for that state-by-state picture, firearms licences in Australia for why self-defence is not a genuine reason for a licence, and prohibited weapons in Australia for classification.

After a Self-Defence Incident

What happens after a self-defence incident, including arrest, police interview, and the right to silence and to a lawyer, is covered on Miranda rights in Australia, since those processes vary by state and are not specific to self-defence law. This page describes the legal test only; it is not advice about what to do or say in a specific situation. For the national comparison across all eight jurisdictions, including the excessive self-defence table and the castle doctrine myth, see self-defence laws in Australia.