Prediction market resolution rules are the controlling instructions for deciding which outcome a contract pays. Read them as a compact specification: identify the exact question, threshold, unit, time window, timezone, named evidence source, treatment of revisions and delays, edge cases, and final decision-maker before relying on the market title.［1］

Key Takeaways

A market title summarizes the topic; full rules control settlement.

Small words such as “at least,” “before,” “official,” and “first published” can decide the outcome.

Trading close, event end, source publication, and finalization may be different times.

A named source can be more important than broader public agreement about what happened.

Save the rule version and evidence source before a result becomes disputed.

Why are prediction market resolution rules more than a headline?

A headline must fit a card, search result, or app screen. It rarely contains every condition needed for a deterministic payment. “Will the city reach 30°C on Friday?” still leaves open the weather station, observation type, local-day boundary, rounding, exact threshold, missing data, correction policy, and whether Friday is defined locally or in UTC.

The full rules turn that natural-language idea into an operational test. CFTC consumer material emphasizes access to complete contract information and settlement decisions in the US event-contract context.［1］ The lesson travels well even where the legal framework does not: a participant cannot evaluate a contingent claim from a slogan alone.

Kalshi distinguishes a short rules summary from complete market rules and a verification source in its own help material.［2］［3］ That is one platform's documentation structure, not a universal format, but it illustrates why three texts that look similar may serve different purposes.

The ten-field rule-reading worksheet

Copy the values rather than merely checking that a section exists. A blank or vague answer is itself useful risk information.

Field	Question to answer	Ambiguity to flag
1. Contract question	What precise proposition settles Yes?	Headline uses undefined shorthand
2. Threshold	Is the boundary above, below, at least, or exactly?	Equality and rounding are unstated
3. Unit	Which currency, scale, category, or measurement applies?	Similar units can produce different results
4. Event window	When can the qualifying fact occur?	Start or end is missing
5. Timezone	Which clock defines dates and deadlines?	Local time and UTC can cross dates
6. Official source	Which publication, feed, agency, or oracle controls?	“Official reports” names no source
7. Revisions	Does first release or later corrected data count?	Source can revise after the deadline
8. Delay or cancellation	What if the event is postponed, abandoned, or unavailable?	No fallback or expiration rule
9. Edge cases	How are ties, ranges, substitutions, and conflicting reports handled?	Plausible outcomes are omitted
10. Authority	Who determines, reviews, and finalizes?	Source and decision-maker are confused

Keep the worksheet with the market URL and capture time. If rules are later amended under an allowed process, the saved version helps establish what changed; it does not guarantee that the earlier text will govern.

How do time, timezone, and thresholds change an answer?

Time language has multiple layers. A market may stop accepting orders before the real-world observation period ends. The source may publish data hours later. A determination may follow, then a challenge window, and only after that may the result become final.

“Before 5 p.m.” excludes a reading stamped exactly at 5 p.m. in ordinary usage, while “by 5 p.m.” may include it. “Above 30” excludes exactly 30, while “at least 30” includes it. Rules should also explain whether a displayed 30.0 was rounded from a value below the threshold.

Timezone can switch the calendar date. An event at 00:30 UTC may still belong to the previous day in New York and the same morning in Hong Kong. Never infer the governing zone from the user's device clock or the city named in the title.

How should you inspect the official resolution source?

Confirm the source at the level the rule actually names. An agency homepage is not the same as a specific data series; a television announcement is not the same as a certified result; an oracle proposal is not yet a finalized oracle answer.

Then ask four practical questions:

Is the source publicly accessible, or does the platform rely on a private feed?
Does it publish preliminary and revised values?
What happens when the source is silent, delayed, removed, or internally inconsistent?
Does the platform reserve interpretation authority even when the source supplies the underlying fact?

Polymarket documents an architecture involving market rules, a resolution source, an end date, and edge cases, coupled to its oracle process.［4］ Use that as an on-chain example. A centralized exchange may assign the same functions differently, and another oracle system may use different bonds, voters, or escalation stages.

A harmless weather example

Imagine the title “Will Harbor City reach 30°C on 10 July?” The complete rule says Yes if Station H's highest one-minute air temperature is at least 30.0°C between 00:00 and 23:59 local time, using the agency's daily final report first published by noon the next day. If the station is unavailable for more than six hours, the market is void.

Now compare plausible facts:

A nearby airport reports 31°C, but Station H reports 29.8°C: the named station controls, so the airport result is irrelevant.
Station H reports 29.96°C and the website displays 30.0 after rounding: the rule needs a rounding instruction or underlying precision.
A preliminary report says 30.1°C and the daily final says 29.9°C before noon: the “daily final” clause selects the latter.
The reading occurs at 00:05 the following day: it falls outside the local window even if another timezone still shows 10 July.
Station H is missing for eight hours: the explicit void clause applies instead of guessing from another station.

None of these examples predicts weather or recommends a trade. They show how contract wording, not the broad story “the city was hot,” determines settlement.

What do cancellation, postponement, and invalid market outcomes mean?

Do not assume postponed means No. A rule may extend the observation window, substitute an approved source, wait for rescheduling, or declare the market invalid. “Invalid” may trigger a platform-specific refund or equal-value mechanism rather than either substantive outcome winning.

Likewise, an event can happen after trading closes but before the contract expires. Early closing may manage operational risk without changing the event window. Find separate clauses for last trading time, event deadline, determination, dispute, and payment.

If two official publications conflict, look for hierarchy: certified over preliminary, named agency over media reports, later revision over first release, or the reverse. If no hierarchy exists, ambiguity belongs in the risk assessment rather than being silently resolved by personal preference.

What should you save before a problem occurs?

Preserve a small evidence packet:

the full rule text and its version or capture time;
the market title, identifier, URL, and status;
the named source page or data release;
timestamps with timezone shown explicitly;
relevant notices about amendment, delay, cancellation, or challenge;
your own transaction records, if applicable, kept separate from public debate.

This packet does not give your interpretation priority. It lets you compare the platform's action with the published process and use the correct channel if a prediction market result is disputed.

Summary

Treat full resolution rules as the settlement specification and the title as a summary.
Fill all ten worksheet fields before interpreting price or outcome.
Separate trading close, event time, publication, determination, dispute, and finalization.
Follow the named evidence source and its revision policy, not a more persuasive but unlisted source.
Preserve rules and timestamps early because disputed pages and statuses can later change.

Frequently Asked Questions

Do resolution rules override the market title?

The full rules ordinarily define the controlling settlement criteria, while the title is a summary. Check the venue's contractual hierarchy because the exact legal relationship remains platform-specific.

What is an official resolution source?

It is the publication, dataset, authority, feed, or oracle named by the contract as evidence. “Official” should identify something precise enough to retrieve and compare.

Does exactly the threshold count as Yes?

Only the operator in the rule answers that. “At least” includes equality, “above” does not, and rounding can require a separate clause.

Which timezone applies to a prediction market?

Use the timezone explicitly named in the rules. The user's device, venue headquarters, event location, and data source can all use different clocks.

What if the official data is revised?

Look for a first-release, final-release, or correction deadline. Without such a clause, record the ambiguity and follow the venue's designated clarification or dispute process.

Does postponement automatically settle No?

No. The contract may extend, wait, use a replacement condition, or become invalid. The market-specific delay and cancellation language controls.

Can rules change after trading starts?

Some venues reserve narrow amendment powers for errors or unforeseen cases. Check notice, versioning, and challenge provisions; saving the earlier text helps you identify the change.

Are on-chain rules automatically objective?

No. Code can automate payments, but people still choose wording, sources, oracle design, challenge incentives, and upgrade powers. Ambiguity can move from an operator's desk into an oracle dispute.

Disclaimer: This article is general educational information, not financial, investment, trading, tax, or legal advice. Contract rules, legal rights, deadlines, and resolution mechanisms differ by platform and jurisdiction and may change.

Sources:

CFTC — Prediction Markets and Event Contracts — https://www.cftc.gov/LearnandProtect/PredictionMarkets
Kalshi — Market Rules — https://help.kalshi.com/en/articles/13823822-market-rules
Kalshi — Rules Summary — https://help.kalshi.com/en/articles/13823823-rules-summary
Polymarket — Resolution — https://docs.polymarket.com/concepts/resolution

Sources checked 6 September 2026.

Related reading:

How to Read Prediction Market Resolution Rules