The 7 General Defences in Tort Law: A Complete Case Matrix

What it is: A complete defence where the plaintiff voluntarily agrees to take a risk upon themselves, fully appreciating and anticipating the extent of that danger. If you consent to a known risk, you cannot later claim injury.

Simple Example: If you buy a ticket to sit in the front row of a baseball game, you implicitly consent to the inherent risk of a foul ball flying into the stands and hitting you.

What it is: Based on public policy, this prevents a plaintiff from claiming damages if their injury is directly connected to their own illegal or wrongful conduct. The law will not recognize a duty of care between participants in a joint criminal enterprise.

Simple Example: If two burglars are fleeing a crime scene in a getaway car and the driver crashes, the injured passenger cannot sue the driver for negligent driving.

What it is: A defence used when a truly unforeseeable event happens despite the defendant exercising reasonable care, caution, and skill. It applies only when there is absolutely no negligence on the part of the defendant.

Simple Example: A driver is operating a perfectly maintained vehicle at a safe speed when an unpredictable, catastrophic mechanical failure occurs, causing a crash.

What it is: An unprecedented, extraordinary natural event that is completely beyond human control and could not reasonably be anticipated or guarded against. It fails if human negligence worsens the impact.

Simple Example: A freak, once-in-a-century meteor strike destroys a roof, causing debris to fall and damage a neighbor’s property.

What it is: The law permits the use of reasonable force in good faith to protect oneself or one’s property from an apparent and immediate danger. The force must be absolutely necessary and strictly proportionate to the threat.

Simple Example: Pushing an attacker away who is actively swinging their fists at you to escape unharmed.

What it is: Committing an act that causes damage, but doing so in good faith to prevent a much greater, imminent harm (choosing the lesser evil). It can apply to public welfare or private protection.

Simple Example: Smashing a stranger’s car window to rescue a dog trapped inside on a dangerously hot day.

What it is: An act completely authorized by a statute or law. If the authority is absolute, it provides complete immunity for inevitable harm; if conditional, the act must be performed without negligence.

Simple Example: The government legally acquires a person’s private farmland to build a state highway; the interference with property rights is protected by statute.