In law, to distinguish a case means a court decides the holding or legal reasoning of a precedent case will not apply due to materially different facts between the two cases. Two formal constraints constrain the later court: the expressed relevant factors (also known as considerations, tests, questions or determinants) in the ratio (legal reasoning) of the earlier case must be recited or their equivalent recited or the earlier case makes an exception for their application in the circumstances otherwise it envisages, and the ruling in the later case must not expressly doubt (criticise) the result reached in the precedent case.

The ruling made by the judge or panel of judges must be based on the evidence at hand and the standard binding authorities covering the subject-matter and areas of law cited in or plainly relevant to the dispute (they must be followed).

This means that a precedent will be dealt to (in English and Scottish law known instead as applied to) a case with similar facts, in which a decision can then be distinguished based upon this, or it may be cited with approval but found to be inapplicable on bases reconcilable with the earlier decision's reasoning.