History
The Rule Against Perpetuities in Property Law
Quick fact
A famous application of the Rule Against Perpetuities invalidated a bequest to 'my descendants who are living 100 years after my death'—because that could vest beyond a life in being plus 21 years, the law declared it void.
Why this is interesting
You might think you can leave your house to whoever you want, whenever you want—but what if you tried to give it to your 'future grandchildren'? The law would actually stop you, and here's why.
Read the full explanation
Understanding The Rule Against Perpetuities in Property Law
Imagine you want to control who gets your property long after you're gone. The Rule Against Perpetuities (RAP) is a legal rule that limits how far into the future you can dictate that. It says that any future interest (like a right to receive property later) must 'vest'—that is, the recipient must be identified and the conditions satisfied—within a certain timeframe. That timeframe is 'a life in being plus 21 years.' A 'life in being' means a person alive when the interest was created (e.g., when the will or deed took effect). The simplest way to think about it: you can tie up property for a person's lifetime, plus 21 years after that, but not longer. If there's any possibility, even a tiny chance, that an interest could vest after that period, the law strikes it down completely. This might seem harsh, but it's meant to keep property freely transferable and prevent the 'dead hand' of the past from controlling ownership forever.
A deeper explanation
The Rule Against Perpetuities (RAP) is a judge-made doctrine dating to the 17th century, designed to limit the duration of future interests in property. Its core mechanism is the 'vesting' requirement: any contingent remainder, executory interest, or similar future interest must vest, if at all, within the perpetuity period. This period is measured from the creation of the interest (e.g., the effective date of a will or deed) and is defined as 'a life in being plus 21 years.' A 'life in being' is any person alive at the creation of the interest who is relevant to the vesting condition—for example, a named beneficiary or the testator. The rule applies to the possibility of vesting, not the actual outcome. Thus, if there is any conceivable scenario—no matter how improbable—in which the interest could vest after the period has expired, the interest is void at the outset. The rationale behind RAP is to prevent the 'dead hand' of a deceased grantor from controlling property for an unreasonably long time, which would hamper alienability and the efficient use of resources. It reflects a policy balance between honoring a grantor's intent and ensuring that property remains marketable. Over time, criticisms of the rule's technicality led to statutory reforms. Many jurisdictions adopted the Uniform Statutory Rule Against Perpetuities, which sets a fixed period of 90 years from the creation of the interest, and some states have abolished or significantly modified the rule for certain trusts. These reforms preserve the rule's core purpose while avoiding its harsh, sometimes accidental, invalidation of clearly intended gifts. The RAP remains a classic example of how legal doctrines can evolve to balance historical policy goals with modern practical needs.