4.1 Contract Types and Required Elements

Key Takeaways

  • A valid contract requires offer/acceptance (mutual assent), consideration, legal capacity, legal purpose, and—for real estate—a writing under the Statute of Frauds.
  • Contracts are classified by formation (express vs. implied), by obligations (bilateral vs. unilateral), and by enforceability (valid, void, voidable, unenforceable).
  • A counteroffer rejects and terminates the original offer; the original cannot then be accepted unless re-extended.
  • Most purchase agreements and listings are bilateral and express; an option is the classic unilateral contract.
  • Real estate sale contracts, leases over one year, and listing agreements generally must be in writing to be enforceable.
Last updated: June 2026

Contract Types and Required Elements

Real estate transactions are contract-driven, so the exam tests both the vocabulary of contracts and the five elements that make one legally binding. A contract is a voluntary, legally enforceable agreement between competent parties to do (or not do) a lawful act in exchange for consideration.

Classifying Contracts

Examiners ask you to classify the same agreement three different ways: by how it is created, by who is obligated, and by whether a court will enforce it.

  • Express - terms stated in words, oral or written (a signed purchase agreement).
  • Implied - created by the conduct of the parties rather than words.
  • Bilateral - both parties promise to perform (a promise for a promise).
  • Unilateral - one party promises to act only if the other actually performs; an option is the classic example.

Most purchase agreements and listing agreements are express and bilateral: each side makes a promise. Recognizing the option as unilateral is a frequent trap—the optionor is bound, but the optionee is free to walk away.

The Five Required Elements

Memorize these for the validity questions:

ElementWhat it meansExam trap
Mutual assentA definite offer and an unqualified acceptance ("meeting of the minds")A counteroffer rejects the original and ends it
ConsiderationSomething of legal value exchanged by each partyEarnest money is evidence of consideration, not the consideration itself
Legal capacityParties must be of legal age and sound mindA contract signed by a minor is voidable by the minor
Legal purposeThe objective must be lawfulAn agreement to violate fair housing is void
Writing (Statute of Frauds)Real estate sales/leases >1 yr must be writtenAn oral land-sale contract is unenforceable, not automatically void

Mutual Assent and the Counteroffer Rule

An offer must be communicated, definite, and accepted exactly as written. Any change to price, terms, or dates is a counteroffer: it rejects the original offer and becomes a new offer the original offeror may accept or reject. The original offer cannot be revived unless re-extended. This is one of the most heavily tested mechanics on the national exam.

Enforceability Categories (Worked Example)

The four enforceability labels are routinely confused. Distinguish them precisely:

  • Valid - meets all five elements and is fully enforceable.
  • Void - no legal effect from the start; e.g., a contract for an illegal purpose, or one party lacked capacity (adjudicated incompetent).
  • Voidable - valid until the disadvantaged party elects to disaffirm; e.g., a contract signed by a minor, or one induced by fraud, duress, or misrepresentation.
  • Unenforceable - valid between the parties but a court will not compel it; e.g., an oral real estate contract barred by the Statute of Frauds.

Worked example: A 17-year-old signs a purchase agreement. Because a minor lacks full capacity, the contract is voidable at the minor's option—the minor may enforce it or disaffirm it, but the adult seller cannot escape it. Contrast that with a contract to sell land that was never reduced to writing: it is unenforceable under the Statute of Frauds, yet if the parties voluntarily perform, the transfer stands.

A common trap pairs "a minor's contract" with the answer "void." The correct answer is voidable—void would mean it never existed, which is wrong because the minor can choose to enforce it.

Statute of Frauds in Practice

The Statute of Frauds requires that contracts for the sale of real estate, leases longer than one year, and most listing agreements be in writing and signed by the party to be charged. The writing must identify the parties, the property, the price or a method to determine it, and the essential terms. A handshake deal to sell a house is not enforceable in court even if witnesses confirm it.

Note two refinements the exam likes. First, partial performance—such as a buyer who takes possession and makes improvements—can sometimes overcome the writing requirement in equity. Second, the writing need not be a single formal document; a series of signed memos, emails, or a signed check with terms may together satisfy the statute. Still, the safe exam answer is that real estate sale contracts must be written to be enforceable.

Offer, acceptance, and the option contract in detail

Because the unilateral option is the most-tested contract type beyond the standard purchase agreement, master its mechanics. An option gives the optionee the right but not the obligation to buy within a set period at a set price, in exchange for separate option consideration that the optionor keeps whether or not the option is exercised. The optionor is bound to hold the offer open; the optionee may simply walk away and forfeit only the option fee.

Worked option example: A buyer pays $5,000 for a 90-day option to purchase at $300,000. If the buyer exercises, contracts typically credit the $5,000 toward the price, so the buyer owes $295,000 more. If the buyer lets the option lapse, the seller keeps the $5,000 and is free to sell elsewhere. Contrast this with earnest money, which is not a separate purchase of time but a good-faith deposit on a bilateral contract.

Offer-termination rules to memorize: an offer ends by (1) the offeree's rejection or counteroffer, (2) lapse of the stated time, (3) revocation by the offeror before acceptance is communicated, (4) death or incapacity of either party before acceptance, or (5) destruction of the subject property. Acceptance is effective when communicated to the offeror; a silent intention to accept does not form a contract. Examiners frequently test the moment of formation: the deal exists the instant a valid acceptance is communicated, not when the deposit clears or the documents are recorded.

Test Your Knowledge

A buyer offers $250,000. The seller responds in writing offering to sell at $260,000. Before the buyer answers, the seller's agent calls to say the seller now accepts the original $250,000. What is the legal status?

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Test Your Knowledge

An oral agreement to sell a parcel of land is best described as:

A
B
C
D