rule against perpetuities

The rule against perpetuities is a principle used mainly in property law. The common law definition of the rule against perpetuities states that if an interest in real property does not vest within 21 years of life-in-being (life in existence) at the creation of the interest, then that interest in land is not good. However, the common law definition is rather vague, and many states have a hard time deciphering the exact meaning of the rule against perpetuities. As a result, many different jurisdictions have modified the common law rule against perpetuities, and other jurisdictions even abolished the rule altogether.

The interest could be present interest (present right to the real property) or future interest (the right to the real property in the future). For an interest to “vest,” it means that the right to a specific real property has reached a known, verified individual. The rule against perpetuities kicks in when no known and verified individual has acquired the interest within the 21 years time limit of any life in being. The transfer of the right to land violates the rule against perpetuities if there is even a remote possibility that no life in being would acquire the interest in land.

Life in being refers to the individual who receives the right to real property from the original grantor. Generally, an identifiable “measuring life” in being is needed at the creation of the interest because there cannot be a gap in time between the measuring life and the creation of the interest. The original grantor typically assigns a specific individual as a final recipient who is identifiable at the transfer. Also, if dealing with the future interest in the right to land, the length of time is measured by the person. Thus, the problem may occur if it is uncertain who will receive the right to land. Finally, the measuring life in being does not have to be an individual but can be a class of individuals, as long as the class is closed (cannot accept additional members to the class after the initial appointment).

[Last updated in April of 2024 by the Wex Definitions Team]