Jurisprudence, Interpretation and General Laws · Law of Torts

General Defences in the Law of Torts

Updated 11 October 2026 · Fact-checked

General defences in tort are pleas a defendant raises to escape liability even when the plaintiff has proved a wrongful act and damage. They include volenti non fit injuria, necessity, act of God, inevitable accident, private defence, statutory authority and plaintiff's fault. Solve questions by naming the defence, testing its conditions against the facts, and concluding.

Understand General Defences in Tort

In a tort claim, the plaintiff must show a wrongful act and legal damage. Even then, the defendant may not be liable. A general defence is a plea that takes away liability because of special circumstances. It is called general because it can be raised against many different torts, such as negligence, trespass or nuisance.

The first group depends on the plaintiff's own role. Volenti non fit injuria means no wrong is done to a person who consents. If you knowingly and freely take a risk, you cannot sue for the harm that follows. The consent must be free and given with full knowledge of the risk. Knowing of a risk is not the same as agreeing to it. A related defence is plaintiff's fault (contributory negligence), where the plaintiff's own carelessness helped cause the harm.

The second group depends on events outside the defendant's control. Act of God is an extraordinary natural event that no human foresight could guard against, such as an unprecedented earthquake or a freak flood. Inevitable accident is an event the defendant could not have avoided by reasonable care and caution. It need not be natural. The key difference: act of God needs a natural force of extraordinary kind, while inevitable accident only needs that reasonable care could not prevent it.

The third group is justified conduct. Private defence allows reasonable force to protect your person or property. Necessity allows a harmful act to prevent a greater harm, for example pulling down a house to stop a spreading fire. Statutory authority protects acts done under a law, if the authority is not exceeded and the act is done without negligence. Other defences include mistake, in limited cases, and acts of a person acting under judicial authority.

The common thread: the defendant must prove the defence, and each defence has conditions. Most marks are lost by naming a defence without testing its conditions against the facts.

Key rules to remember

Volenti non fit injuria: Knowledge of risk + free and voluntary agreement to run it = no claim; Both parts are needed. Mere knowledge is not enough. Consent is not a defence where the act goes beyond what was agreed.
Plaintiff's fault (contributory negligence): Plaintiff's own negligence contributing to the harm = damages reduced in proportion; Under the modern approach it reduces damages rather than barring the claim entirely, unless the plaintiff's fault was the sole cause.
Act of God: Extraordinary natural event + not foreseeable or preventable by human care; Needs a natural cause. Ordinary rain or wind does not qualify.
Inevitable accident: Accident that reasonable care and caution could not prevent; Not limited to natural causes. The defendant must show reasonable care was taken.
Private defence: Reasonable and proportionate force to protect person or property; Excessive force makes the defendant liable.
Necessity: Harm caused to avert a greater harm, acting reasonably; The act must be reasonably needed and proportionate to the danger.
Statutory authority: Act authorised by statute, within its limits, without negligence = no liability; If the statute leaves no alternative, the defence is strong. Going beyond the power removes it.

How to solve General Defences in Tort questions

Use the same sequence for any fact-based question on defences. Keep it short and tie each step to the facts.

1Identify the tort alleged and confirm the plaintiff can show a wrongful act and damage.
2List the defences the facts point to. Look for cues: consent or known risk (volenti), natural calamity (act of God), unavoidable mishap (inevitable accident), force used (private defence), harm to avert greater harm (necessity), government or statutory power (statutory authority), plaintiff's carelessness (plaintiff's fault).
3State the rule of each defence in one or two lines, with its conditions.
4Apply each condition to the facts one by one. Mark which are met and which fail.
5Note any limit: consent was not free, force was excessive, care was not taken, power was exceeded.
6Add a well-known case only if you are sure of it and it fits the point.
7Write a clear conclusion: whether the defence succeeds, and whether liability is full, reduced or nil.

Quickest way: Cue-and-condition method

When to use it: When time is short and the question is a short fact pattern or a short note.

Underline the cue word in the facts: consent, flood, unavoidable, force, fire, statute, careless.
Write the matching defence name at once.
Write its one-line rule and its key condition.
Say in one line whether the condition is met.
Close with the result: liable, not liable or damages reduced.

Common mistakes in General Defences in Tort

Treating knowledge of risk as consent under volenti.
Students read the maxim loosely as 'the plaintiff knew the danger'.
Fix: State that the plaintiff must also freely agree to run the risk. Knowledge alone is not agreement.
Using act of God and inevitable accident as the same thing.
Both involve events beyond control, so they look alike.
Fix: Say act of God needs an extraordinary natural force. Inevitable accident can have any cause but must be unavoidable despite reasonable care.
Applying private defence without checking proportion.
Students focus on the right to defend and forget its limit.
Fix: Always add that the force must be reasonable and proportionate. Excess force is itself a wrong.
Saying plaintiff's fault always bars the whole claim.
Students carry over the old rule that any contributory fault defeated the claim.
Fix: State that damages are reduced in proportion to the plaintiff's share of fault, unless that fault is the sole cause.
Assuming statutory authority protects every act done under a statute.
The word 'authority' sounds like total immunity.
Fix: Add the conditions: the act must be within the power given and done without negligence. The statute's wording matters.
Citing cases from memory with wrong facts or holdings.
Students try to add weight to the answer without being sure.
Fix: Cite a case only if you are certain of name and holding. A correct rule applied to the facts earns marks without a doubtful case.

Worked examples

Example 1

Ravi, a spectator, buys a ticket for a motor race held on an open track. He sits in the open stand where a notice warns that cars may leave the track. A car skids, enters the stand and injures him. Ravi sues the organiser. Discuss the defence of volenti non fit injuria.

Show the solution

Provision: volenti non fit injuria means a person who knowingly and freely agrees to run a risk of harm cannot sue for it. Both knowledge and free consent are required.
Facts: Ravi saw the notice, so he knew that cars might leave the track. He chose to sit in that stand and paid for the ticket, so his consent was voluntary.
Limit: the consent covers risks that are inherent in the event. It does not cover harm caused by the organiser's negligence, such as a faulty barrier that should have been maintained.
Analysis: if the skid was an ordinary risk of racing and the organiser took reasonable care, the risk was one Ravi accepted. If the organiser failed to take proper care, the consent does not extend to that failure.

Answer: The defence succeeds if the injury came from a risk inherent in the race and the organiser was not negligent. Ravi cannot recover in that case. If the organiser was negligent, volenti does not protect it and Ravi can claim.

Example 2

A dam built by a company with proper care breaks after an unprecedented cloudburst never seen in the region. The flood damages the crops of Meena, a farmer downstream. Meena sues the company. Examine the defence available and distinguish it from inevitable accident.

Show the solution

Identify the defence: act of God, an extraordinary natural event that human foresight and care could not have prevented.
Test the conditions: the cause is natural (a cloudburst), it is extraordinary (never seen in the region), and the company built the dam with proper care.
Apply: if the rainfall was beyond what a reasonable builder could foresee, the breach was not due to the company's fault.
Distinguish: act of God needs an extraordinary natural force. Inevitable accident is wider. It covers any accident that reasonable care could not avoid, even one with a human cause.
Note a caution: if the dam was poorly built or if heavy rain was reasonably foreseeable, the defence fails.

Answer: The company can plead act of God and is not liable, provided the cloudburst was truly extraordinary and the dam was built and kept with proper care. Inevitable accident would be the wider plea if the cause were not natural.

Exam tips

Questions are often short fact patterns. Name the defence in the first line and spend your time on applying its conditions.
Distinction questions, such as act of God versus inevitable accident, are common. Write two or three clear points of difference.
In a short note, give the meaning, the conditions, one simple example and the limits of the defence.
Always end with a conclusion that says whether liability exists. A rule without a conclusion loses marks.
Use cases only when you are sure of them. Clean rules with correct application are safer.

Practice questions from Law of Torts

General Defences in Tort: frequently asked questions

What are the general defences in the law of torts?

They are pleas that excuse a defendant from liability even when a wrong and damage are shown. The main ones are volenti non fit injuria, necessity, act of God, inevitable accident, private defence, statutory authority and plaintiff's fault.

What is the difference between act of God and inevitable accident?

Act of God requires an extraordinary natural event, such as an unprecedented flood or earthquake. Inevitable accident covers any accident that could not be avoided by reasonable care, whether the cause is natural or not. Act of God is therefore a narrower category.

What is volenti non fit injuria?

It means no wrong is done to one who consents. If you knowingly and freely accept the risk of harm, you cannot later sue for it. The consent must be free and given with full knowledge of the risk.

Does contributory negligence completely bar a claim?

Generally no. The plaintiff's own carelessness reduces the damages in proportion to the plaintiff's share of fault. It defeats the claim fully only if the plaintiff's fault was the sole cause of the harm.

Who has to prove a defence in tort?

The defendant who raises the defence must prove it. The plaintiff first proves the wrongful act and damage, and then the defendant shows that the conditions of the defence are met.