What does 'balance of probabilities' mean in a civil lawsuit in Ontario?

Balance of probabilities is the standard of proof that applies in civil cases in Ontario. It means the party making a claim must prove that their version of events is more likely than not to be true — in other words, there is a greater than 50% chance that what they are saying happened. It is sometimes described as "the scales tipping" in the plaintiff's favour.

This is a lower standard than the criminal law standard of proof beyond a reasonable doubt. In civil litigation, you do not need to eliminate all doubt — you simply need to show it is more probable than not that your position is correct. This makes civil claims more accessible than criminal prosecutions, but the plaintiff still bears the burden of proof on each element of their claim.

If the evidence is evenly balanced and the judge cannot determine which side is more likely correct, the plaintiff fails and the defendant wins. Each element of a cause of action (for example, negligence) must be proven on a balance of probabilities. Understanding this standard helps set realistic expectations for litigation.