12. A reversion. When the holder of a vested estate transfers to another a smaller estate, we call the interest which remains in the grantor a “reversion.” Since the estate created by O is smaller than the one he held (i.e., a life estate is smaller than a fee simple absolute), what O was left with was a reversion.
13. Indefeasibly vested remainder. A remainder is a future interest which can become possessory only upon the expiration of a prior possessory interest created by the same instrument. Since B’s interest was created by the same instrument that created A’s life estate, and since B’s interest will become possessory when that prior life interest expires, B has a remainder. This remainder is a vested remainder, because it is not subject to any condition precedent, and an identified already-born person (B) holds the remainder. The remainder is “indefeasibly” vested because it is certain to become possessory at some future time (even if B dies before A does, the remainder will pass by will or intestacy to B’s heirs, and there is certain to be somebody who will be there to take possession when A dies).
14. Vested remainder subject to open. For an explanation of why C’s interest is some sort of vested remainder, see the answer to the prior question. The vested remainder is “subject to open” because if another child (let’s call him D) is born to B, C’s remainder “opens up” to give D a half interest in it. The remainder will stay open until either A dies (in which case only the then-living children of B will take anything), or B dies, in which case he can have no further children.
15. Vested remainder subject to divestment. B has a remainder vested subject to divestment. If A died immediately, B’s interest would become possessory. But if B died without issue (either before or after A’s death), B’s interest would be completely defeated or “divested.” (C’s interest, which cuts short B’s vested interest, is called an executory interest.)
16. Contingent remainder. A remainder is contingent rather than vested if it is either subject to a condition precedent, or created in favor of a person who is unborn or unascertained. Here, the remainder to B is subject to a condition precedent (the condition that B survive A in order for his remainder to become possessory). If B does survive A, his remainder will become vested at the same time it becomes possessory.
17. Vested remainder subject to divestment. Notice that the grant here is functionally indistinguishable from that in the prior question, yet the remainder here is vested (subject to divestment), whereas the one in the prior question is contingent. This relates solely to the words: here the clause creating the remainder in B does not contain any limit, and the limit is introduced by a separate clause containing the phrase, “but if.” As a matter of interpretation, the separate clause beginning with “but if” indicates that the remainder is being “taken away,” and this indicates a condition subsequent rather than a condition precedent (thus a remainder subject to divestment rather than a contingent remainder).
18. Fee simple in O. After the initial conveyance by O, D had a contingent remainder. But at the time A died, D did not meet the contingency (having had a child while being married). By the common-law doctrine of destructibility of contingent remainders, a contingent remainder was deemed “destroyed” unless it vested at or before the termination of the preceding freehold estates. Since D had not met the contingency by the time the prior estate (A’s life estate) expired, D’s contingent remainder was destroyed. Therefore, O’s reversion became possessory, giving him a fee simple absolute. (Today, most states have, by case law or statute, abolished the doctrine of destructibility of contingent remainders.)