Official rules
Last updated October 21, 2026
These rules apply to every ProofOfSolve puzzle. Paid puzzles also follow the extra rules in section 17.
1. Who runs ProofOfSolve
ProofOfSolve is run by a crypto enthusiast. It's meant to be fun and is for entertainment only. ProofOfSolve wants to show that crypto can be fun. The prizes are real. There are no other sponsors of this site. If you have questions, contact support@proofofsolve.com.
2. Free puzzles
Free puzzles cost nothing to play. No purchase is necessary to enter or win a free puzzle. Donating never helps you win, and never gives you extra tries or hints.
3. Who can play
- You must be 18 or older.
- Open worldwide, except where the law doesn't allow it and except for people in countries or regions under United States sanctions. It's up to you to make sure taking part is legal where you live.
- Not eligible: the people who run ProofOfSolve, anyone who helps make or test a puzzle, and their immediate families and households.
4. A contest of skill
Each puzzle is a contest of skill with no element of chance. The winner is the first person to submit the correct answer.
5. How to play
- Each puzzle opens at the time posted on its page, for everyone at the same moment.
- The clues lead to 12 seed words, all from the BIP39 English word list of 2,048 words. A word may be written at the spot, or it may be the name of something you see there, such as an object, an animal or a color. Your answer is those 12 words in clue order, entered on the puzzle's page.
- A spot may show a seed word as a plural or with ’s, such as “teams” or “team’s” on a sign when the seed word is “team”. Those are the only changes we ever make: no other endings (like -ing or -ed), no abbreviations and no other words that mean the same thing. Your answer always uses the word exactly as it’s spelled on the BIP39 list.
- The puzzle’s page has 12 numbered boxes, one for each clue, in order. Capital letters and extra spaces don’t matter. A word that isn’t on the BIP39 list, or 12 words that don’t form a valid seed, are caught before your answer is sent and never use a try.
- You can use any tools you like, including maps, search engines and AI. Everything you need can be found online.
- Never visit a puzzle location in person, go onto private property, or contact people who live or work at a location. Doing so can disqualify you.
6. Tries
- On free puzzles, each email address gets 3 tries per puzzle in any 24 hours, and each internet connection gets 6. On paid puzzles, each entry code gets 3 tries in any 24 hours (see section 17). Answers that aren't a valid seed are rejected without using a try.
- One person, one email address. Addresses that differ only by a "+" tag, or by dots in a Gmail address, count as the same address. Using more than one email address, someone else's identity, scripts, bots or any other way around these limits will disqualify you, and we may cancel answers that look automated.
- To stop guessing by brute force, our server checks at most 8 different answers per puzzle in any 24 hours that share the same 11 words in the same places. An answer held back by this limit counts as a try, and you can send it again once the limit clears.
7. Who wins
- Our server records the time each answer arrives. The first correct answer by that time wins, and our server's clock is the official clock.
- Once a puzzle is solved, it stops taking answers.
- Before each puzzle opens we publish its answer fingerprint. After it's solved we publish the answer and its salt, so anyone can confirm the answer never changed.
8. Claiming a prize
- The winner sees a claim code on screen. Email it to support@proofofsolve.com from the same email address you entered with your answer. There's no deadline.
- If you'd like, tell us where you're from and the name you'd like to go by online, so we can share them when we announce the win.
- Once we've checked your claim code, we email you the prize wallet's passphrase, usually within 24 hours, and you move the prize to your own wallet. The steps are on our How to claim page.
- If the winner isn't eligible or broke these rules, the prize goes to a future puzzle.
9. The prize
- The prize is the bitcoin in the puzzle's prize wallet. Its address is on the Puzzles page, so anyone can check the balance on the blockchain.
- Dollar amounts are approximate. Bitcoin's value goes up and down, and we don't guarantee what it's worth in dollars.
- The winner pays the normal network fee when moving the prize. Prizes can't be swapped for cash or transferred to someone else.
- Bitcoin payments can't be reversed. Once we've sent you the passphrase, keeping the prize safe is up to you.
10. Taxes
Winners are responsible for any taxes on their prize.
11. If nobody solves it
A puzzle stays open until it's solved.
12. Fair play and problems
- We may disqualify anyone who cheats, tampers with the site, or plays unfairly.
- If a technical problem, a mistake in a puzzle or anything else outside our control affects a puzzle's fairness, we may pause, fix or restart it.
- If Google changes or removes the Street View imagery a clue depends on, we’ll post the same fix for everyone at the same time. Every fix stays listed with its date under Corrections, right above the puzzle’s clues, and we also announce it on r/proofofsolve and by email to our list.
- Our decisions about these rules are final.
13. Publicity
When a puzzle is solved, we post the solve time and the payout transaction on the Puzzles page, along with the winner's chosen name and where they're from if they shared them (otherwise "Anonymous"). We never publish email addresses.
14. Privacy
How we handle your email address and answers is explained in our privacy policy.
15. Limits of responsibility
As far as the law allows, we aren't responsible for answers that are lost, late or not received; problems with the internet, our server, your device or any wallet software; or any injury or loss that comes from taking part. Void where prohibited.
16. Changes
We may update these rules. The version posted when a puzzle opens is the one that applies to that puzzle.
17. Paid puzzles
Paid puzzles follow all of the rules above, plus these:
- Entry fee. A paid puzzle's page shows its entry price. You pay in bitcoin on the puzzle's page, through pay.proofofsolve.com, our own BTCPay Server. Your wallet's network fee is extra. After you send it, a payment can take up to 10 minutes to show up. Payment opens when the puzzle opens and stops when it's solved.
- What you get. Each payment unlocks the puzzle's clues and gives you one entry code. The code shows the clues on any device and gives you 3 tries every 24 hours on that puzzle, for as long as it's open. Keep your code private: anyone who has it can see the clues and use its tries.
- The clues are for people who paid. Until a paid puzzle is solved, its clues are only shown with a paid entry code. After it's solved, everyone can see them.
- Where paid puzzles are open. Everyone who can play under section 3, except people located in Colorado, Maryland, Nebraska, North Dakota or Vermont. You confirm you're eligible before you buy, and we also check where your connection comes from.
- The prize doesn't depend on entries. The prize is the bitcoin already in the puzzle's prize wallet, published before the puzzle opens. Entry fees don't go into the prize. They pay for running ProofOfSolve and future puzzles.
- Paying gets you the clues and your tries, nothing else. Everyone who pays gets the same clues, and the first correct answer wins, just like a free puzzle.
- No refunds. Entry fees aren't refundable, including after the puzzle is solved. If we ever have to cancel a paid puzzle before anyone solves it, every entry code bought for it will also work on our next paid puzzle, at no extra cost.
- Payment problems. If you send less than the full amount, no code is issued until the rest arrives. If you paid and no code showed up after 10 minutes, use the entry code page with your invoice ID, or email support@proofofsolve.com. Bitcoin payments can't be reversed, so check the amount before you send.