Mass. Gen. Laws ch. 184A, § 7: Fee simple determinable in land or fee simple subject to right of entry for condition broken; term

Section 7. A fee simple determinable in land or a fee simple in land subject to a right of entry for condition broken shall become a fee simple absolute if the specified contingency does not occur within thirty years from the date when such fee simple determinable or such fee simple subject to a right of entry becomes possessory. If such contingency occurs within said thirty years the succeeding interest, which may be an interest in a person other than the person creating the interest or his heirs, shall become possessory or the right of entry exercisable notwithstanding the rule against perpetuities.