You’re staring at an MBE question that starts with “O conveys Blackacre to A for life, then to B if B graduates from law school.” Your brain immediately screams: What interest does B have? Is it a remainder? An executory interest? Does the Rule Against Perpetuities apply? And what happens if B never graduates?

Future interests are where most bar takers lose points in Real Property. The terminology sounds like medieval Latin, the categories overlap in confusing ways, and one wrong classification can tank an entire question. But here’s the good news: future interests follow predictable patterns. Once you understand the core distinctions, these questions become mechanical.

What Are Future Interests and Why Do They Matter?

A future interest is a present right to future possession of property. The holder doesn’t get to use the property now, but they have a legally recognized stake that will (or might) ripen into possession later.

The MBE tests future interests relentlessly because they force you to analyze multiple legal concepts at once: property classification, conditions precedent versus subsequent, the Rule Against Perpetuities, and transferability rules. A single conveyance can create three or four different interests, and you need to classify each one correctly.

Future interests fall into two camps: those retained by the grantor and those created in third parties. Master this distinction first, because it determines which specific interest you’re dealing with.

Grantor’s Future Interests: Reversion, Possibility of Reverter, and Right of Entry

When a grantor conveys less than they own, they automatically retain a reversion. This is the default. If O conveys “to A for life” and says nothing else, O keeps a reversion. When A dies, the property returns to O (or O’s heirs if O is dead). Reversions are vested interests—they’re certain to become possessory eventually. They’re freely transferable, devisable, and descendible. Critically, reversions are not subject to the Rule Against Perpetuities.

Now consider a different conveyance: “to A so long as the property is used as a school.” O has created a fee simple determinable in A. Notice the durational language—“so long as,” “while,” “during,” or “until.” This triggers an automatic termination if the condition is violated. O retains a possibility of reverter, which becomes possessory automatically the moment A stops using the property as a school. No court action needed. The property just reverts.

Compare that to: “to A, but if the property ceases to be used as a school, grantor may re-enter and retake the premises.” This is a fee simple subject to condition subsequent. The condition is stated, but O must affirmatively exercise the right of entry (also called a power of termination). If A violates the condition and O does nothing, A keeps the property. The key difference from possibility of reverter? It’s not automatic—O must act.

Here’s the MBE trap: students confuse these two because both involve conditions and both give the grantor a future interest. Focus on the language. Durational words create determinable estates with possibilities of reverter. Conditional language with explicit re-entry rights creates condition subsequent estates with rights of entry.

Neither possibility of reverter nor right of entry is subject to the Rule Against Perpetuities at common law. That’s a major distinction from third-party future interests.

Third-Party Future Interests: Remainders and Executory Interests

When a future interest is created in someone other than the grantor, you’re dealing with either a remainder or an executory interest. The distinction turns on one question: does the interest wait politely for the prior estate to end naturally, or does it cut short the prior estate?

A remainder follows a life estate or term of years and becomes possessory only when that prior estate terminates naturally. Classic example: “to A for life, then to B.” B has a remainder. When A dies (the natural end of a life estate), B takes possession. Remainders never divest anyone—they wait their turn.

Remainders subdivide into vested and contingent. A vested remainder is created in an ascertained person with no condition precedent. In “to A for life, then to B,” B’s remainder is vested. B is identified, alive, and there’s no condition other than A’s death (which is just the natural termination of the prior estate, not a true condition precedent).

A contingent remainder exists when the holder is unascertained or when there’s a condition precedent beyond the natural termination of the prior estate. Examples: “to A for life, then to A’s children” (if A has no children yet—unascertained), or “to A for life, then to B if B graduates from law school” (condition precedent). The condition must occur before the remainder becomes possessory.

There’s also the vested remainder subject to open—a remainder held by a class where at least one member is identified but more could join. “To A for life, then to A’s children” when A has one child creates this. The class “closes” under the rule of convenience when any member is entitled to immediate distribution.

Executory Interests: The Estate Cutters

An executory interest is a future interest in a third party that divests a prior estate before its natural termination. It cuts someone off. There are two types.

A shifting executory interest divests another transferee. Example: “to A, but if A fails the bar exam, then to B.” A has a fee simple subject to executory limitation. If A fails the bar, B’s interest automatically divests A. B doesn’t wait for A’s estate to end naturally—B cuts A off.

A springing executory interest divests the grantor. Example: “to A when A marries.” Until A marries, O retains a fee simple. When A marries, A’s interest “springs” out of O’s estate and divests it.

Here’s the critical MBE distinction: remainders follow life estates or terms of years. Executory interests follow fee simple estates (usually defeasible ones) or they cut short a prior interest. If you see “to A for life, then to B,” that’s a remainder—it follows a life estate. If you see “to A, but if B graduates, then to B,” that’s an executory interest—it cuts short A’s fee simple.

The Rule Against Perpetuities: Where Future Interests Go to Die

The Rule Against Perpetuities (RAP) is the final boss of future interests. The rule: no interest is valid unless it must vest or fail within a life in being at the creation of the interest plus twenty-one years.

RAP applies to contingent remainders, executory interests, and vested remainders subject to open (class gifts). It does not apply to reversions, possibilities of reverter, rights of entry, or vested remainders.

Classic RAP trap: “to A for life, then to A’s children who reach age twenty-five.” Seems fine, right? Wrong. A could have a child after the conveyance is created (not a life in being). That child might not reach twenty-five until more than twenty-one years after all lives in being have ended. The remainder to A’s children is void under RAP.

Another trap—the fertile octogenarian: the law presumes anyone can have children regardless of age. “To A for life, then to A’s grandchildren” can fail RAP because A (age eighty) is presumed capable of having more children, whose children might not be ascertained within the perpetuities period.

When an interest violates RAP, strike it out. Then re-classify what remains. If “to A for life, then to B if B graduates from law school” violates RAP (it doesn’t, but hypothetically), you’d strike B’s interest and O would have a reversion following A’s life estate.

Many states have reformed RAP with “wait-and-see” statutes or the Uniform Statutory Rule Against Perpetuities, which provides an alternative ninety-year vesting period. The MBE typically tests common law RAP unless the question specifies otherwise.

Transferability: Who Can Sell, Devise, or Pass These Interests?

All future interests are generally alienable, devisable, and descendible—with exceptions.

Reversions and vested remainders are freely transferable in all respects. You can sell them, leave them in your will, or pass them to heirs.

Possibilities of reverter are transferable, devisable, and descendible in most jurisdictions. Rights of entry historically were not transferable inter vivos (during life), though the modern trend allows it. Both are devisable and descendible.

Contingent remainders and executory interests are alienable in most jurisdictions, but not all. Some states still follow the common law rule that contingent interests cannot be transferred during life.

This matters on the MBE when a question asks whether an interest can be conveyed or what happens when the holder dies before the interest becomes possessory. A vested remainder passes to the holder’s estate. A contingent remainder might not, depending on the jurisdiction and the terms of the conveyance.

Putting It All Together: A Step-by-Step Approach

When you see a conveyance on the MBE, work through this sequence:

  1. Identify the present estate. Is it a fee simple (absolute, determinable, subject to condition subsequent, subject to executory limitation), a life estate, or a term of years?

  2. Identify the language. Durational language (“so long as,” “while,” “until”) creates determinable estates. Conditional language with re-entry rights (“but if… grantor may re-enter”) creates condition subsequent estates. Conditional language with a gift over to a third party creates executory limitations.

  3. Classify the future interest. If it’s in the grantor, determine whether it’s a reversion (follows a life estate or term of years), possibility of reverter (follows a determinable estate), or right of entry (follows a condition subsequent estate). If it’s in a third party, determine whether it’s a remainder (follows a life estate or term of years and doesn’t divest) or an executory interest (divests a prior estate).

  4. Determine if the remainder is vested or contingent. Is the holder ascertained? Is there a condition precedent other than natural termination?

  5. Apply RAP if necessary. Does the interest have to vest or fail within a life in being plus twenty-one years? If not, strike it and re-classify.

Let’s apply this: “O conveys to A for life, then to B if B survives A, otherwise to C.”

A has a life estate. B has a contingent remainder (condition precedent: B must survive A). C has a contingent remainder (alternative contingency: B does not survive A). O has a reversion (in case both contingent remainders fail—if both B and C predecease A).

Neither contingent remainder violates RAP because both will vest or fail at A’s death—a life in being. When A dies, we’ll know immediately whether B survived. If yes, B takes. If no, C takes. If both B and C are dead, O’s reversion becomes possessory.

What to Memorize for Test Day

Lock in these rules:

Grantor’s interests: Reversion (follows life estate or term of years, automatic, vested). Possibility of reverter (follows fee simple determinable, automatic). Right of entry (follows fee simple subject to condition subsequent, requires affirmative action).

Third-party interests: Remainder (follows life estate or term of years, doesn’t divest). Executory interest (divests a prior estate—shifting divests a transferee, springing divests the grantor).

Vested vs. contingent remainder: Vested = ascertained person, no condition precedent. Contingent = unascertained person or condition precedent.

RAP: Applies to contingent remainders, executory interests, and class gifts. Does not apply to reversions, possibilities of reverter, rights of entry, or vested remainders. Interest must vest or fail within a life in being plus twenty-one years.

Key language: “So long as / while / until” = determinable estate + possibility of reverter. “But if… grantor may re-enter” = condition subsequent + right of entry. “But if… then to [third party]” = executory limitation + executory interest.

Future interests on the MBE are pattern recognition. You’re not reinventing the wheel on each question—you’re applying the same classification framework repeatedly. The examiners test your ability to spot durational versus conditional language, distinguish remainders from executory interests, and apply RAP correctly. If you can do those three things consistently, you’ll pick up points that other test-takers leave on the table.

If you want all of these rules organized in a format built for active recall, FlashTables Real Property covers future interests along with every other property doctrine tested on the MBE—111 rules total, structured in two-column tables that force you to practice retrieval rather than passive re-reading. It’s the method a practicing attorney used to pass the bar, and it works because it mirrors how you’ll actually need to access these rules under timed pressure: fast, accurate, and without second-guessing yourself.