Locality rule refers to a principle that in professional-malpractice suit, the standard of care to be applied to the professional's conduct is the reasonable care exercised by similar professionals in the same vicinity and professional community. This rule is not of much relevance today. Earlier, a physician need only possess and apply knowledge and use the skill and care that is ordinarily used by reasonably well-qualified physicians in the locality in which s/he practices. This made it difficult or impossible for a plaintiff to prove the applicable standard as other doctors in the same locality are notoriously reluctant to testify against their professional colleagues. However, with the advent of improved communication and continuing medical education, the reason for the rule has abated.
Locality rule also refers to the principle that, in determining the appropriate amount of attorney's fees to be awarded in a suit, the proper basis is the rate charged by similar attorneys for similar work in the vicinity.