MBE Rules · Real Property
Rule Against Perpetuities
The rule
No interest is good unless it must vest, if at all, no later than 21 years after some life in being at the creation of the interest. Applies to contingent remainders, executory interests, options, and rights of first refusal. Strict common-law rule; many jurisdictions adopt wait-and-see or USRAP (90 years).
In plain English
The Rule Against Perpetuities prevents property interests from being uncertain for too long. It ensures that future interests in property must become definite within 21 years after the death of a relevant person alive when the interest was created.
Worked example
A grants land to B for life, then to B's first child to graduate college. If B's child graduates more than 21 years after B's death, the interest is void under the Rule Against Perpetuities.
Memory hook
21 and done, or it's none. Interests must vest within 21 years of a life in being to avoid perpetuities issues.
The trap
Students think: Any future interest is void if it doesn't vest in 21 years. Wrong, because it only applies to contingent remainders, executory interests, options, and rights of first refusal. The actual test is whether they must vest within the period.
How examiners test it
The MBE loves: a will creating a contingent remainder for grandchildren. Trap: assuming it's valid without checking if it must vest within 21 years of a measuring life.
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