Illinois real estate exam glossary
Unilateral contract
Start with what the offer asks you to do. Does it invite a promise, or does it promise a benefit for a particular act? That question is more useful than counting signatures or calling the bargain one-sided.
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The short answer
A unilateral offer seeks acceptance through the specified performance rather than a return promise. A familiar example is a known reward offer accepted by completing the requested act. The performance can supply both acceptance and consideration. A bilateral contract instead exchanges promises. For real estate options, distinguish the supported promise to keep an offer open from the later act that validly exercises the purchase or renewal right.
National V.A.7 in the PSI outline covers bilateral and unilateral contracts; V.A.8 covers options. The whole Contracts area has 19 of 100 scored national broker questions, not nineteen on this term. Reviewed October 26, 2026. The examples use their stated assumptions and do not decide a live contract or option dispute.
Find the requested acceptance before choosing the label
- Identify a definite offer. Read the promised benefit, the person or group entitled to respond, the requested act and any conditions. A hope, a gift promise or a possible future negotiation is not automatically an enforceable performance bargain.
- Identify how acceptance must occur. If the offer requires an act, a promise to do it later does not substitute for that act. If it requests reciprocal commitments, a bilateral contract can form before either party completes the future performance.
- Check knowledge and the actual conduct. In the classic reward example, the performer acts knowing of the offer. An act completely finished before learning of the reward is different from responding to the offer. Preserve what was communicated and when.
- Separate preparation, performance and the payment condition. Travelling to search, starting a search and finding and returning the item are different events. The offer determines the requested result. Whether it can still be revoked is a separate legal question from whether the payment condition has been met.
- Read an option in two parts. A supported option binds the keep-open promise for its stated term. The underlying offer gives the optionee a choice. Follow the actual exercise terms, including the required notice, recipient, deadline and any required tender; paying for the option is not automatically exercise.
- Keep formalities and other duties in view. A unilateral label does not remove applicable land-writing, signature, electronic-record or brokerage-agreement requirements. Record the relevant acts and receipt evidence, and have disputed rights assessed under the full agreement and governing law.
| Event | What it may establish | What it does not establish alone |
|---|---|---|
| A definite offer is communicated | An opportunity to accept under its terms | That the requested act has been completed |
| The offeree promises to act later | A return promise | Acceptance when only the finished act was invited |
| The offeree prepares or starts work | Facts relevant to the stage of performance | That a completion-based payment is already earned |
| The required act is completed knowingly | Acceptance of the stated classic performance offer | That unrelated legal formalities disappear |
| Option consideration is provided | Support for the keep-open promise | Automatic exercise or a transfer of title |
| The option is validly exercised | Acceptance of the underlying offer as provided | That closing and conveyance have already occurred |
The distinctions that matter
| Distinction | How it works | What to notice |
|---|---|---|
| Unilateral and bilateral | A unilateral offer asks for the specified performance as acceptance. A bilateral offer asks for a return promise. Both involve parties; unilateral does not mean one participant or one signature. | Identify what counts as acceptance, rather than what remains to be done. |
| Acceptance and later performance | A signed purchase agreement can bind buyer and seller through exchanged promises while payment and conveyance remain future obligations. Unfinished closing duties do not make that agreement unilateral. | Formation can occur before completion. |
| Preparation and the requested act | Getting ready may differ from beginning the actual requested work, and both may differ from completing it. The exact offer and facts matter. | Do not convert travel time into an automatically earned reward. |
| Revocability and earned payment | The status of the offer, the work undertaken and any supported keep-open promise must be assessed separately from the condition for payment. Unilateral does not mean the promisor can freely rewrite an existing obligation. | Not yet paid is not a complete revocation analysis. |
| Option consideration and exercise | Consideration supports the option right. Exercise invokes the underlying offer in the required way. Refunds and any credit toward the price depend on the actual agreement. | Buying a choice is different from making the choice. |
| Electronic format and effective notice | An electronic record or signature can receive legal recognition under current Illinois law. That does not make every text message, typed name or sent email effective exercise under every option. | Check agreement to use the format, attribution, the notice terms and any receipt requirement. |
Work through the facts
The known reward is completed
An owner offers $1,000 for finding and returning a particular lost key by Friday. The searcher knows of the offer, finds the key and returns it as required before the deadline. No competing claim or other qualification is supplied.
- The offer requests a result rather than a promise to search.
- The stated act is completed with knowledge of the offer.
Answer: The supplied facts fit acceptance of the classic unilateral reward offer.
The act was finished before the reward was known
A neighbor finds and returns the key on Monday without knowing of any reward. On Tuesday the neighbor first learns that a reward had been offered.
- The act was already complete before the offer was known.
- Later knowledge does not turn the earlier act into acceptance of that offer.
Answer: The facts do not establish the classic reward contract through that earlier act. A statute or a separate later promise would require its own analysis.
A promise to search is not the promised result
The offer expressly promises payment only for finding and returning the key. A person replies, I promise to search tomorrow, but does nothing further.
- The response is a promise rather than the requested act.
- The stated payment condition has not occurred.
Answer: The reply does not complete acceptance of the supplied act-only offer or earn the reward.
Work has started, but the required result is missing
The informed searcher spends two hours looking but has not found or returned the key. No payment for hours worked or partial results is offered.
- Effort is different from the specified completed result.
- The stage of work can raise separate questions about the offer; it does not alone establish the full payment condition.
Answer: The stated reward is not yet earned on these facts. Do not use that answer as a ruling that withdrawal or interference would necessarily be lawful.
Both parties have promised future performance
A buyer promises to pay $420,000 and a seller promises to convey the identified property under a valid signed purchase agreement. Neither has completed closing yet.
- The parties exchanged commitments.
- Future closing obligations are performance under an existing agreement, not proof that no contract formed.
Answer: This is the supplied bilateral purchase contract.
Paying for the option is not exercise
An optionee pays $3,000 for a supported purchase option. The option separately requires an unconditional exercise notice by the stated deadline. No notice is sent and no exception is supplied.
- The payment supports the decision period.
- The required later exercise act is absent.
Answer: Payment alone does not exercise this option, transfer title or create the optionee's purchase obligation. Fee treatment still depends on the agreement.
The response changes the bargain
Before the option deadline, the optionee writes that exercise is conditional on the owner reducing the agreed price by $15,000. No owner acceptance or waiver is supplied.
- The response adds a material price condition.
- Being sent before the deadline does not make it unconditional exercise.
Answer: The response does not satisfy the supplied option's unchanged exercise terms. Treat the new condition as a proposed different bargain.
Sent before the deadline, received after it
For this example, the option expressly permits email but requires receipt in the designated system by 5:00 p.m. on October 20, 2026. A compliant message is sent at 4:59 p.m. and first enters that system in retrievable, processable form at 5:01 p.m. No different receipt rule, extension, waiver or equitable exception is supplied.
- The stated clause makes receipt, rather than sending, the relevant event.
- The supplied receipt is one minute after the deadline, although transmission began one minute before it.
- The general recognition of electronic records does not rewrite the agreed deadline.
Answer: The supplied facts do not establish timely exercise under that receipt-based clause. Preserve the actual delivery evidence; do not substitute the sent timestamp.
Mistakes to avoid
- Unilateral means only one person signs. Classify the requested acceptance, not the signature count.
- A promise to perform always accepts an offer seeking a completed act. Match the actual act-only acceptance terms.
- Any effort earns the full reward. Check the specified result and any express partial-payment terms.
- No completed payment means the offer can always be withdrawn freely. Keep payment conditions, performance stage and any keep-open obligation separate.
- An option fee is automatically refundable, credited or sufficient to exercise. Read the separate fee and exercise provisions.
- An email timestamp proves every notice requirement. Check the agreed system, recipient, actual delivery or receipt requirement and governing law.
- A unilateral label eliminates current brokerage paperwork. Apply the actual Illinois agreement and licensing rules as well.
Check your understanding
These are original teaching questions, not recalled or predicted PSI questions. Answer first, then explain why the other choices fail.
1. What does a unilateral offer seek as acceptance?
- The performance specified in the offer
- A deed in every case
- Only an unrelated return promise
- A particular number of signatures in every case
Show answer and explanation
Answer: A. The performance specified in the offer
Classify what the offer asks the offeree to do. Performance can supply acceptance and consideration when the actual conditions are met.
2. Does unilateral mean that only one person is involved?
- Only if no fee is paid
- Yes, because there is no offeree
- No; it describes the requested mode of acceptance
- Yes, if the contract is electronic
Show answer and explanation
Answer: C. No; it describes the requested mode of acceptance
There is an offeror and an offeree. The distinction concerns performance as acceptance rather than an exchanged promise.
3. The informed offeree completes every stated condition of the supplied valid reward offer. Which classification fits?
- A counteroffer solely because an act occurred
- An uncommunicated gift
- Acceptance of a unilateral performance offer
- A transfer of title automatically
Show answer and explanation
Answer: C. Acceptance of a unilateral performance offer
The act requested by the known offer is completed on the supplied facts.
4. The requested act was fully completed before the person first learned of the reward offer. What is the sound conclusion?
- The later discovery itself performs the act again
- The earlier act did not accept that unknown offer in the classic contract analysis
- Every reward must still be paid under contract law
- The person has become the optionor
Show answer and explanation
Answer: B. The earlier act did not accept that unknown offer in the classic contract analysis
The earlier act was not a response to the offer. Do not confuse a separate statutory or later-promise issue with acceptance of this offer.
5. An offer expressly requires finding and returning the key. The offeree only promises to search tomorrow. What is missing?
- The requested performance
- A second property description
- A later gift receipt
- A deed-tax stamp
Show answer and explanation
Answer: A. The requested performance
An act-only offer is not accepted by substituting a promise to try.
6. A completion-based reward offers no hourly or partial payment. A search has begun, but the item is not found or returned. What follows?
- The specified payment condition is not yet met; offer protection is a separate question
- The offeror can always interfere with completion
- The searcher automatically owns the lost item
- The full reward is automatically earned
Show answer and explanation
Answer: A. The specified payment condition is not yet met; offer protection is a separate question
Keep the condition for payment separate from revocability or other rights arising from the actual work and terms.
7. A valid purchase agreement exchanges a buyer's payment promise for a seller's conveyance promise. Closing is still pending. What is it?
- A bilateral contract with future performance duties
- A gift promise only
- No agreement until the deed is recorded
- A unilateral reward solely because closing is unfinished
Show answer and explanation
Answer: A. A bilateral contract with future performance duties
Reciprocal promises can form the contract before payment and conveyance occur.
8. What does consideration for a supported option ordinarily support?
- The promise to keep the underlying offer open under the option terms
- Automatic acceptance of every future purchase term
- A universal right to a refund
- Immediate transfer of title
Show answer and explanation
Answer: A. The promise to keep the underlying offer open under the option terms
The option right and its later exercise are distinct. The optionee generally retains the choice whether to exercise.
9. A supported option requires a separate exercise notice. The fee is paid, but no notice or exception is supplied. What follows?
- The fee alone does not exercise the option
- The fee necessarily transfers title
- The buyer must always receive the fee back
- The option is always automatically exercised
Show answer and explanation
Answer: A. The fee alone does not exercise the option
Use the actual separate exercise requirement. Credit and refund treatment are different terms.
10. An optionee says exercise is conditional on a $15,000 price reduction, without any owner agreement or waiver. What is the problem?
- The response is automatically a deed
- The response is necessarily too early
- The added material condition does not match unconditional exercise
- An option can never involve a stated price
Show answer and explanation
Answer: C. The added material condition does not match unconditional exercise
Timing alone does not cure a material condition that changes the held-open bargain.
11. Does legal recognition of electronic records make every email effective option exercise?
- No; the actual agreement, attribution and notice requirements still matter
- Yes, whatever the option says
- Only if the subject line says urgent
- Yes, if the sender uses a typed first name
Show answer and explanation
Answer: A. No; the actual agreement, attribution and notice requirements still matter
Current UETA addresses recognition, agreement, attribution and default transmission rules. It does not erase the parties' actual requirements.
12. A question describes a nonexclusive listing with a promise to pay for a specified result and no broker promise to produce it. What is the best approach?
- Classify it solely by one signature
- Assume a commission is always earned only at closing
- Ignore current Illinois agreement rules
- Recognize the supplied performance structure while applying the actual agreement and law
Show answer and explanation
Answer: D. Recognize the supplied performance structure while applying the actual agreement and law
The model can illustrate unilateral acceptance. Do not turn that classification into a universal commission trigger or paperwork exemption.
13. The supplied option requires email receipt by 5:00 p.m. A compliant message is sent at 4:59 and received at 5:01, with no exception supplied. Which conclusion follows?
- The fee automatically cures lateness
- Every email is deemed received when written
- Sending always controls every option deadline
- The supplied receipt is late under that clause
Show answer and explanation
Answer: D. The supplied receipt is late under that clause
The stated receipt requirement controls the example. Receipt at 5:01 is one minute late. This is not a universal rule that every option permits email or uses the same receipt test.
14. An actual offer expressly permits either an identified return promise or a stated act as acceptance. How should you analyze it?
- Apply the actual permitted alternatives rather than forcing an act-only rule onto it
- Ignore both alternatives and count signatures
- Insist that only the act can ever count
- Assume no consideration could ever exist
Show answer and explanation
Answer: A. Apply the actual permitted alternatives rather than forcing an act-only rule onto it
The offer's actual terms matter. An offer expressly permitting a return promise is different from the act-only reward examples.
Common questions
What is a unilateral contract?
It arises from an offer seeking acceptance by the requested performance rather than a return promise. A known reward offer is the familiar teaching example. The definite terms, actual act, consideration and other applicable requirements still matter.
What is the quickest way to distinguish bilateral and unilateral contracts?
Ask what accepts the offer. Exchanged promises are the bilateral structure. An act specified as acceptance is the unilateral structure. Do not count signatures or assume that unfinished future duties mean a contract has not formed.
Can performance itself supply consideration?
Yes, when the requested act is the bargained-for exchange. The court's contract-formation instruction recognizes acts as possible value and performance as a possible way of accepting. A gratuitous act unrelated to the bargain is a different issue.
Is an unknown reward offer accepted by an already completed act?
Not in the classic contract example. If the person fully completed the act before learning of the offer, later knowledge does not make that earlier act a response to it. Independent statutory rights or a separate later promise need their own analysis.
Does a promise to try accept a completion-based reward?
No, if the offer specifically requests the completed act and permits no return-promise acceptance. Read any stated alternative or partial-payment provision before deciding what performance is required.
Does starting work always earn the promised amount?
No. The actual payment condition matters. Starting work, satisfying the condition and having rights concerning the status of the offer are separate questions. This glossary does not announce one automatic revocation rule for every kind of performance offer.
Does unilateral mean the promisor may change the terms freely?
No. Do not confuse a performance-based bargain with permission to rewrite an existing obligation. In Doyle, the Supreme Court rejected the particular adverse handbook modification for lack of consideration. Its employment facts do not decide every reward or real estate contract.
How does an option relate to a unilateral contract?
Illinois option decisions distinguish the supported keep-open promise from the underlying offer. The optionee can ordinarily choose whether to exercise, then must comply with the actual exercise terms. The label does not automatically create title or excuse other requirements.
Is the option fee the purchase price or an exercise notice?
Not automatically. It supports the option right. Whether it is credited toward the price, refundable or separately retained depends on the agreement. A required exercise notice or tender remains a separate condition.
Does timely notice always exercise an option?
Timeliness is only one requirement. The response also must satisfy the actual terms, including required specificity, certainty, unconditional acceptance, method, recipient and any tender. Waiver or equitable arguments require their own factual and legal assessment.
Can an option be exercised electronically?
Potentially, under the actual agreement and applicable law. Illinois UETA recognizes electronic records and signatures in its scope, with agreement and attribution requirements. A clause requiring receipt by a designated method is not satisfied merely by pointing to a sent message.
Is an open listing always unilateral?
The teaching label fits a supplied structure in which the owner promises compensation for a specified result without a broker promise to produce it. Actual agreements can contain additional obligations. Apply current Illinois written-agreement and licensing requirements, and read the fee trigger instead of assuming every commission requires a completed closing.
Does unilateral mean an oral real estate agreement is always enforceable?
No. The Frauds Act and other applicable requirements still matter. Illinois law addresses land-contract writings and signatures, and current electronic-record law can be relevant. The label alone does not establish compliance or an exception.
Are these official PSI questions?
No. They are original teaching scenarios. The PSI outline identifies the topic, while the cited primary materials support the explanations. A result here is not a validated readiness score or a legal decision about a real file.
Can an offer permit more than one way to accept?
Yes, when its actual terms do so. Do not impose an act-only rule on an offer that expressly invites either a return promise or identified performance. Check which permitted method was used and whether its conditions were satisfied.
Keep practising
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Official sources and scope
The court's contract-formation instruction addresses a definite offer, acceptance and consideration. Doyle illustrates acceptance through informed performance in its particular handbook setting. The option decisions address distinct real estate arrangements; their facts and limits matter. Current Illinois electronic-record law is in 815 ILCS 333, rather than the repealed 5 ILCS 175 provision formerly cited here.
- PSI June 24, 2026: bilateral and unilateral contracts
- Illinois Pattern Civil Jury Instructions 700.03: contract formation
- Doyle v. Holy Cross Hospital, 186 Ill. 2d 104 (1999)
- Whitelaw v. Brady, 3 Ill. 2d 583 (1954): option structure and writing
- The Terraces of Sunset Park v. Chamberlin (2010): paid purchase choice
- Michigan Wacker, 2018 IL App (1st) 171222: commercial extension-option notice
- 740 ILCS 80/2: land-contract writing and signature
- 815 ILCS 333/5, 7 and 9: electronic agreement, recognition and attribution
- 815 ILCS 333/15: electronic sending and receipt
- 68 Ill. Adm. Code 1450.770, effective July 13, 2026: agreement and listing-side assistance timing
This is exam preparation, not advice for a specific transaction. State law and the applicable facts control. Our editorial and corrections process explains how to report an issue.