Weilers LLP

What is Contributory Negligence?

What is Contributory Negligence?

September 18, 2023

By Brian Babcock

What happens when an injured person is partly at fault for their own injury?

At one time, historically, any negligence by the injured party (the Plaintiff) and they were totally barred from suing. This was great news for people that left the sidewalks unmaintained or for careless drivers. A successful argument that the Plaintiff should have watched where they were going relieve them of any responsibility.

In England and in Canada, we have moved away from this strict position. In Ontario, the  Negligence Act was passed into law in 1947. This moves us into a position of what is technically known as comparative negligence. Responsibility for negligence in an accident is divided in  accordance with the respective (or comparative) degrees of fault. So, if the Defendant is 90 percent at fault and the Plaintiff 10 percent, Plaintiff recovers 90 percent of their loss.

However, if there are multiple defendants, each may be required to pay 100 percent of the Plaintiff’s recovery. Comparative negligence applies between defendants in that scenario.

If the fault is 40% Defendant A, 40% Defendant B and 10% Plaintiff, the Plaintiff can collect 90% of his losses from either A or B, whichever is easier for them. If Plaintiff collects only from A, then A can turn around and attempt to collect half the payment from B. This is handy if one defendant has  insurance and the other does not.

If only one person is at fault, no apportionment is necessary. The Act does not apply.

Fault is always a question of fact. It must be apportioned so that the total is 100 percent. The determination of degrees of fault is made by a judge or jury based upon all of the evidence. If they cannot determine fairly how to apportion fault, in Ontario, it is divided equally between each person with fault. Prior decisions will often provide guidance as to degrees of fault, but the facts are seldom identical. Care must also be taken in comparing cases from other provinces, where the legislation may vary.

The concept of contributory negligence and the Negligence Act applies only in cases of fault through a tort, which captures most accidents (negligence) and many cases of strict liability or intentional torts (such as assault- think a bar fight). Breaches of fiduciary duty and breaches of contract do not apply to the Negligence Act, so comparative negligence does not apply in the same way. To make this a bit more complicated, if a breach of contract is caused through negligence, the Act may apply.

Comparative negligence does apply in many property or economic torts (but not fraud), not just in cases of personal injury.

As you might have gathered, the application of the concepts of contributory negligence, comparative fault, and the Negligence Act can be quite technical, and as with all matters of law, it is best to seek specific legal advice on your situation.


Weilers LLP has a proud tradition of excellence in litigation, with much of our work falling into the basket of tort claims. We act for both defendants and plaintiffs (and insurers too). Whether you are a victim of negligence or are being sued, the experienced team at Weilers LLP might be the right lawyers for you.