Your Chance to Win – Enter Now!!
A fun, community-driven way to grow Bitcoin adoption.
Better Odds. Better Money.
⚡ Live Bitcoin Competitions
Answer the Question, pay in sats, and be in with a chance to win! 🚀
Loading BTC price...
🟠 What Are Your Odds?
Current BTC Price: $--
Entry: 2,100 sats (≈ $--)
| Draw | Your Odds | Others (Comparison) |
|---|---|---|
| 🟠 0.021 BTC Draw ($--) |
1 in 2,100 | Local 4-number lottery: 1 in 10,000 |
| 🟠 0.21 BTC Draw ($--) |
1 in 21,000 | General raffle sites: 1 in 100,000+ |
| 🟠 2.1 BTC Draw ($--) |
1 in 210,000 | UK National Lottery: 1 in 45 million |
✓ Better Odds. Better Money.
How it works
Choose your competition
Select your competition and check out all the details about it.
Answer the question
Submit your answer and pay. You will receive your draw number(s)
The Excitement Begins!
You're in with the chance to win - Look out for the next draw!
Freeze entries
Hash and modulo
Pick the winner
Bitcoin settles every draw, not us.
We do not choose winners – the Bitcoin network does. The next block, our pre-commit hash and simple maths create a result that nobody can quietly change. You can check the steps yourself.
Entries are frozen
When the draw closes we take a snapshot of every ticket number that was sold. That list is locked. No late entries. No edits. No removals.
Bitcoin creates the randomness
We take the next Bitcoin block hash and combine it with our public pre-commit value. SHA-256 turns them into one large random number.
Modulo chooses the winner
We apply random_number % tickets_sold.
That modulo step turns the big number into a position in the frozen list.
The ticket in that position wins. No bias. No human judgement.
On the Winners page we publish the block hash, pre-commit hash, the underlying secret and the full calculation. You can run the same modulo maths and confirm the exact winning ticket yourself.
21 STACKER Winners
Every draw is provably fair. Every winner is published. Real Bitcoin wins, out in the open.
Transparent results you can inspect.
Entries freeze the moment a draw closes.
Verified winners on the public board.
Question? Check our FAQs!
All paid entries are made using Bitcoin via the Lightning Network. It’s fast, secure, and ensures provably fair competition entry. A GBP, EUR & USD equivalent value is displayed for each draw.
21Stacker uses a transparent draw system that combines a pre-published server seed with a publicly available Bitcoin block hash. This process ensures that no one can manipulate the outcome, and every entrant can verify the result.
Each competition clearly states the maximum number of entries per person. Typically, this is capped for each draw in order to keep draws fair and balanced.
Only correct answers qualify for entry. If you answer incorrectly, your entry won’t be processed and no payment will be taken.
We’ll contact you by email and may ask for proof of age and residency. Once verified, your prize (Bitcoin) will be transferred to the Bitcoin wallet address you provide.
Winners have 7 days to complete verification and claim their prize. If not, the prize will be forfeited, and a new winner will be selected.
Yes. To receive your prize, you’ll need an on-chain Bitcoin wallet. Entry fees are paid through the Lightning Network, so you’ll also need a Lightning-enabled wallet for purchases.
Yes, Bitcoin’s price can go up or down. All prizes are paid in Bitcoin only, and 21Stacker is not responsible for changes in value after transfer.
Competitions are open to residents of the UK and Ireland aged 18 or over. Entrants outside these regions may not be eligible to participate.