Criminal Law: What Counts as Reasonable Force in Self-Defence?
Self-defence is one of the most recognised and important legal defences under Criminal Law in Australia. It allows a person to protect themselves, another person, or their property from harm. However, the law does not give unlimited freedom to use any level of force. The question of what is considered reasonable force in self-defence is central to whether the defence will succeed in court.
This article explains how Australian Criminal Law defines reasonable force, the factors courts consider, and what individuals should know if they find themselves relying on self-defence in a criminal matter.
What is Self-Defence Under Criminal Law?
Self-defence is recognised in both common law and statute across Australia. In simple terms, a person is entitled to protect themselves from an attack, provided their response is necessary and proportionate.
Under section 418 of the Crimes Act 1900 (NSW), self-defence applies if:
The accused believed their actions were necessary to defend themselves or someone else, and
Their response was a reasonable reaction in the circumstances as they perceived them.
What Does “Reasonable Force” Mean?
The phrase “reasonable force” is not fixed; it depends on the circumstances of each case. Courts balance two key elements:
Subjective belief - Did the accused genuinely believe they were under threat?
Objective reasonableness - Would an ordinary person view the level of force used as proportionate to the threat?
For example, pushing someone away to stop them from hitting you may be considered reasonable. However, using a weapon against an unarmed attacker might be seen as excessive unless there was a genuine threat to life.
Factors Courts Consider in Self-Defence Cases
When deciding if the force used was reasonable, courts look at:
Immediacy of the threat - Was the danger present and imminent?
Proportionality - Was the response in line with the severity of the threat?
Options available - Could the person have retreated or used less force?
Perception of danger - Did the accused honestly believe they or another person were at risk?
Level of harm caused - The greater the harm, the harder it may be to prove the force was reasonable.
It is important to note that the law does not require a person to measure their response precisely in the heat of the moment. Courts recognise that people act instinctively when faced with danger.
Excessive Force and Its Consequences
If a person uses more force than is considered reasonable, they may not succeed in claiming self-defence. For example:
If a person responds with lethal force to a minor threat, the defence may fail.
That said, Australian courts do take into account the stress and urgency of the situation when assessing whether force was excessive.
Self-Defence in Home Invasions
One area where reasonable force often arises is in cases of home invasions. Australian law permits a person to defend themselves and their property, but again, the response must be proportionate. For instance, using physical force to restrain an intruder may be reasonable, but causing serious harm could be challenged if the intruder was not threatening violence.
The Role of Criminal Lawyers in Self-Defence Cases
Understanding whether force was “reasonable” can be complex. Evidence, witness accounts, and the accused’s perception of events all play a part. This is why obtaining expert legal advice is crucial if you are facing criminal charges involving self-defence.
A Criminal Law specialist can:
Assess whether self-defence applies in your case.
Gather evidence to support your belief of imminent danger.
Represent you in court and challenge the prosecution’s arguments.
Key Takeaways
Self-defence is a valid defence under Criminal Law in Australia.
“Reasonable force” depends on both what the accused believed and what is objectively proportionate.
Courts weigh up the immediacy of the threat, the accused’s perception, and the harm caused.
Using excessive force can lead to criminal liability.
Expert legal advice is essential if you are facing charges and believe you acted in self-defence.
Self-defence is a fundamental legal right, but it comes with limits. The concept of reasonable force ensures that the law balances an individual’s right to protection with the broader principle of preventing unnecessary violence.
At New South Lawyers, we specialise in Criminal Law and have extensive experience in self-defence cases. If you or someone you know is facing charges, don’t navigate the legal system alone.
