Rule Against Perpetuities Definition

An exceedingly complex legal doctrine that limits the amount of time that property can be controlled after death by a person's instructions in a will. The maximum period for which title to real property may be held without being transferred to another is "lives in being plus 21 years." For example, a provision in a deed or will that reads "Title shall be held by David Smith and, upon his death, title may be held only by his descendants until the year 2200, when it shall vest in the Trinity Episcopal Church" is invalid. But a provision stating that "the property will be held by my son George for his life, and thereafter by his son, Thomas, and for 20 years by the Trinity Episcopal Church, before it may be conveyed" is acceptable under the rule.