Tort Law
General Defences in Tort
Learn when consent, necessity, claimant fault, act of God, inevitable accident and private defence can defeat or reduce tort liability.
Quick answer
A general defence does not deny every harmful act; it gives a legal reason why liability should be excluded or reduced on the proved facts.
How a general defence works
First establish the tort. Only then ask whether the defendant has a legally recognised answer.
Volenti non fit injuria
The claimant must freely and knowingly agree to the legal risk, not merely know that danger exists. Consent obtained by pressure, fraud or lack of real choice is ineffective.
Claimant fault
Contributory negligence usually reduces damages because the claimant failed to take reasonable care. It is different from volenti, which can completely answer the claim.
Necessity
Reasonable interference may be justified to prevent a more serious and imminent harm. The response must be proportionate and cannot rest on mere convenience.
Natural events, accidents and protective force
These defences turn on careful proof. A label such as accident or emergency is never enough by itself.
Act of God
The harm must result exclusively from an extraordinary natural event that reasonable foresight and care could not have guarded against. An ordinary seasonal event will rarely qualify.
Inevitable accident
The defendant must show that the accident could not have been avoided despite reasonable care. If negligence contributed, the defence fails.
Private defence
Reasonable force may protect person or property against an imminent wrong. Retaliation, traps intended to injure and disproportionate force fall outside the defence.
Rescue situations
A person who reasonably responds to danger created by the defendant is not normally treated as freely consenting to injury. Rescue is a foreseeable reaction, unless the response is wholly unreasonable.
Landmark cases
Learn the facts, the rule and the reason the case matters. The citation alone will not strengthen an answer.
Hall v. Brooklands Auto-Racing Club
[1933] 1 KB 205Facts: Two racing cars collided during a motor race and one was thrown into the spectator area. The claimant was injured but could not prove that the track or event had been managed negligently.
Legal question: Does a spectator accept the ordinary risks of a properly conducted sport?
Held: A spectator at a properly conducted motor race accepted the ordinary risks inherent in that sport, where negligence by the organiser was not established.
Reasoning: Participation as a spectator carried consent to risks inherent in racing, but not to additional danger created by negligent organisation or concealed defects.
Use in an answer: Use it to show that volenti is limited to the nature and extent of the risk actually accepted.
Haynes v. Harwood
[1935] 1 KB 146Facts: Horses left in a busy street bolted after being disturbed. A police officer entered their path to protect nearby people and was injured while bringing them under control.
Legal question: Is a rescuer barred because he knowingly and voluntarily entered a dangerous situation?
Held: A police officer injured while stopping runaway horses was not barred by volenti because rescue was a reasonable response to danger created by the defendant.
Reasoning: The emergency was created by the defendant and the rescue was a natural, reasonable response. Knowledge of danger did not amount to consent to the resulting injury.
Use in an answer: Use it for the rescue exception and to separate voluntary rescue from voluntary acceptance of injury.
Nichols v. Marsland
(1876) 2 Ex D 1Facts: Exceptionally heavy rainfall caused artificial ornamental pools to overflow and their embankments to fail, sending water onto neighbouring land.
Legal question: Can an extraordinary natural event excuse harm that occurs despite reasonable precautions?
Held: Unprecedented rainfall that overwhelmed carefully maintained artificial pools was treated as an extraordinary natural event.
Reasoning: The rainfall was so unprecedented that reasonable foresight and care could not have guarded against it. The natural event, rather than negligence, was treated as the effective cause.
Use in an answer: Use it as the traditional act of God illustration, then test whether the event was truly unforeseeable.
How to write this answer in an exam
- Identify the completed tort and the party raising the defence.
- State the exact ingredients of the claimed defence.
- Test knowledge, free choice, reasonable care, imminence and proportionality as relevant.
- Conclude whether liability is defeated, damages are reduced or the defence fails.
Quick revision
- The defendant normally proves a general defence.
- Volenti requires free and informed agreement.
- Necessity must answer an imminent greater harm.
- Act of God is exclusively natural and extraordinary.
- Protective force must remain reasonable and proportionate.
Test yourself
- Why is knowledge of risk different from consent to risk?
- When does contributory negligence reduce rather than defeat a claim?
- What fact would prevent an act of God defence?
Frequently asked questions
Is signing a disclaimer conclusive proof of volenti?
No. The court still examines notice, scope, free choice, statutory duties and whether the document actually covered the negligent act.
Can a rescuer claim compensation despite entering danger voluntarily?
Usually yes when the rescue was a reasonable and foreseeable response to danger created by the defendant.