The Rule Against Perpetuities (RAP) limits how long certain future interests can remain uncertain. It is one of the most frequently tested and most confusing topics on the bar exam.
The core rule is that a future interest is invalid unless it must vest, if at all, within 21 years after a life in being at the time the interest was created.
Understanding when RAP applies and how to test it is essential for answering property questions correctly.
What Is the Rule Against Perpetuities?
The Rule Against Perpetuities prevents property interests from being tied up indefinitely. It ensures that ownership will be determined within a reasonable period of time.
The rule applies only to certain types of future interests, not all of them.
The Rule
A future interest is valid only if it must vest or fail within 21 years after the death of a measuring life in being at the time the interest was created.
If there is any possibility that the interest could vest outside that time period, the interest is void from the beginning.
When RAP Applies
RAP applies to:
Contingent remainders
Executory interests
Certain class gifts
RAP does not apply to:
Reversions
Vested remainders
Interests held by the grantor
This distinction is heavily tested.
How to Analyze RAP
Step 1: Identify the future interest
Determine whether the interest is contingent or executory. If it is vested, RAP does not apply.
Step 2: Identify a measuring life
Find a person alive at the time of the conveyance who is relevant to the vesting of the interest.
Step 3: Ask whether the interest must vest or fail within 21 years of that person’s death
If there is any possibility that it could vest later, the interest is invalid.
Common RAP Problems
One common issue involves class gifts, where the interest might vest for some members outside the allowed time period.
Another issue is the “fertile octogenarian” problem, where the law assumes that any person can have children regardless of age.
A third issue is the “unborn widow” problem, where a future spouse might not yet be born at the time of the conveyance.
These hypothetical possibilities often cause interests to violate RAP.
How RAP Is Tested on the Bar Exam
Bar exam questions typically require you to determine whether an interest is valid under RAP.
You must carefully analyze the language of the conveyance and consider all possible scenarios, even unlikely ones.
If there is any possibility of late vesting, the interest is void.
Common Exam Traps
Students often forget that RAP is concerned with possibilities, not probabilities.
Another mistake is applying RAP to interests that are already vested.
A third trap is failing to identify the correct measuring life.
Quick Rule
If there is any possibility that a future interest could vest more than 21 years after a life in being, the interest is void.
Why This Matters
RAP is tested frequently because it forces students to apply strict logical reasoning and consider hypothetical scenarios.
Mastering RAP allows you to quickly eliminate incorrect answers and identify valid versus invalid interests.