operation of law

The phrase "by operation of law" is a legal term that indicates that a right or liability has been created for a party, irrespective of the intent of that party, because it is dictated by existing legal principles. For example, if a person dies without a will, his heirs are determined by operation of law. Similarly, if a person marries or has a child after his or her will has been executed, the law writes this pretermitted spouse or pretermitted heir into the will. Adverse possession, in which title to land passes because non-owners have occupied it for a certain period of time, is another important right that vests by operation of law.
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This term is applied to those rights which are cast upon a party by the law, without any act of his own; as the right to an estate of one who dies intestate is cast upon the heir at law by operation of law; when a lessee for life enfeoffs him in reversion, or when the lessee and lessor join in a feoffment, or when a lessee for life or years accepts a new lease or demise from the lessor there is a surrender of the first lease by operation of law.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.