The one-bite rule is a rule in civil law that declares that owners of dogs will be responsible for providing compensation for injuries caused by bites from their dog, if they had prior knowledge that the dog was prone to biting or other harmful behavior (for example, if the dog had bitten at least once before).
Certain dog bites can cause a lot of damage. This means that treating them medically can cost a lot of money. This is why the one-bite rule exists – to determine whether the owner can be held liable.
However, even though the one-bite rule says that owners can be held liable, the burden of proof rests on the plaintiff to demonstrate that the owner had prior knowledge of the dog's dangerous behavior before the incident occurred.