Self-Defence and Reasonable Force: Sections 34 and 35
Self-defence is not a partial excuse or a mitigating factor. Where it applies, it is a complete answer to the charge, and the Crown must disprove it beyond a reasonable doubt.
Section 34 provides that a person is not guilty of an offence if they believe on reasonable grounds that force or a threat of force is being used against them or another person, the act is committed to defend against it, and the act is reasonable in the circumstances.
What Does Section 34 Require?
Three elements, all of which must be present.
- A reasonable belief that force is being used, or that a threat of force is being made, against the accused or another person (s. 34(1)(a));
- That the act constituting the offence was committed for the purpose of defending or protecting themselves or that other person from that force or threat (s. 34(1)(b));
- That the act committed was reasonable in the circumstances (s. 34(1)(c)).
The belief need only be reasonable, not correct. A person who reasonably but mistakenly believes they are about to be attacked can still act in self-defence.
The provisions were rewritten in 2013, replacing a set of narrower and more technical defences with this single general test. Older commentary describing separate rules for provoked and unprovoked assaults no longer reflects the section.
What Makes an Act 'Reasonable in the Circumstances'?
Section 34(2) requires the court to consider the relevant circumstances of the person, the other parties and the act, including a non-exhaustive list of factors.
- The nature of the force or threat.
- The extent to which the use of force was imminent, and whether other means were available.
- The person's role in the incident.
- Whether any party used or threatened to use a weapon.
- The size, age, gender and physical capabilities of the parties.
- The nature, duration and history of any relationship between the parties, including any prior use or threat of force, and the nature of that force or threat.
- The nature and proportionality of the person's response to the use or threat of force.
- Whether the act was in response to a use or threat of force the person knew was lawful.
The relationship history factor matters a great deal in domestic cases. A response that looks disproportionate viewed in isolation may be reasonable in the context of a history the other person knows and the court is entitled to consider.
Proportionality is a factor, not a rule. The law does not require an exactly measured response from someone under attack.
Can You Defend Someone Else, or Your Property?
Yes to both, under different provisions. Section 34 expressly covers defending another person, on the same terms as defending yourself.
Section 35 covers defence of property. It applies where a person believes on reasonable grounds that they are in peaceable possession of property, or are lawfully assisting someone who is, and that another person is about to enter, is entering or has entered the property without being entitled by law to do so, or is about to take it, is taking it, or has just done so.
The two are not the same, and the force that is reasonable to protect property is generally narrower than the force reasonable to protect a person.
How Does Self-Defence Work at Trial?
It is not something the accused must prove. Once there is an air of reality to the defence — some evidence on which a properly instructed jury could find it applies — the burden is on the Crown to disprove it beyond a reasonable doubt.
That is a significant practical advantage, and it is why the evidence about what led up to an incident matters as much as the incident itself.
It does not follow that claiming self-defence is risk-free. Asserting it generally means accepting that the act occurred, which narrows the other avenues available. Whether to advance it is a strategic decision made with the disclosure, not at the roadside or in a police interview.
Saying 'it was self-defence' to police during an investigation is not the same as running the defence at trial. It is a statement, and it can be used. See our page on the investigation phase.
Frequently asked questions
Browse every answer on this siteYes. Section 34 provides that a person is not guilty of an offence where they reasonably believe force or a threat of force is being used against them or another person, they act to defend against it, and the act is reasonable in the circumstances.
Proportionality is one of the factors under section 34(2) in deciding whether the act was reasonable, not a strict rule. The law does not require a precisely measured response from someone under attack.
Yes. Section 34 applies in the same terms to defending another person as it does to defending yourself.
The Crown must disprove it beyond a reasonable doubt once there is an air of reality to it. The accused does not have to prove self-defence.
Section 35 allows defence of property on defined terms, but the force reasonable to protect property is generally narrower than the force reasonable to protect a person.
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This page is general information about Canadian law, not legal advice, and reading it does not create a lawyer-client relationship. Statutes are amended; provisions are described as at the consolidation reviewed when this page was written.
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