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. There are two formal constraints on the later court: the factors in the ratio of the earlier case must be retained in formulating the ratio of the later case, and the ruling in the later case must still support the result reached in the precedent case.
The ruling made by the judge must be based not only on the evidence they are faced with, but the precedents in which they must follow. This means that a precedent will be dealt to a case with similar facts, in which a decision can then be distinguished based upon this.
Examples
The English cases Balfour v. Balfour (1919) and Merritt v Merritt (1970) both involve a wife making a claim against her husband for breach of contract.