Are provably fair slots really fair?
A provably fair slot lets you prove that a result was locked in before your bet and not touched after it. On Stake Engine slots that check has two parts: the published outcome table of each game mode, and the seed pair that picked your row from it. The odds themselves still favour the house, because every table pays back less than 100% on average.
- Published per mode
- Every possible round with its payout and its weight
- How a bet is decided
- A random draw across that table, weighted (Engine docs)
- What you enter to verify
- Game, version, mode, client seed, server seed, nonce range
- What the verifier returns
- Payout per nonce, running balance, the mode's RTP
- Where
- Engine fairness page and the bonushunt.gg Engine explorer
How an Engine round is decided
Before a game goes live, the studio runs each mode through a simulator hundreds of thousands of times. Every finished round is stored with all the events the screen needs to show it, and the docs call these stored rounds books. A second file lists each book next to its payout and a weight. Heavier weight means that round turns up more often, and the weights together fix the RTP of the mode.
| Round | Weight | Payout | Chance | Adds to RTP |
|---|---|---|---|---|
| 0 | 600 | 0x | 60.0% | 0.00% |
| 1 | 250 | 1.2x | 25.0% | 30.00% |
| 2 | 100 | 2x | 10.0% | 20.00% |
| 3 | 45 | 5x | 4.5% | 22.50% |
| 4 | 5 | 47x | 0.5% | 23.50% |
| Total | 1,000 | 100% | 96.00% |
Invented numbers for illustration. Chance = weight ÷ total weight. RTP = sum of (chance × payout) ÷ mode cost, here a 1x mode. A real slot mode has 100,000 to 1,000,000 rounds (Engine math requirements).
Say you bet $1 on that mode. The server picks a number between 0 and 1,000. Anything up to 600 lands on the losing round, the next 250 on the 1.2x win, and so on down the list, with the 47x round sitting on the last 5. Your timing, your taps and the last ten results don't shift any of those lines, and the animation you watch is just the stored book for the round that came up.
Checking it yourself
- Find the game. Open the Engine fairness page or the bonushunt.gg explorer and pick the game, version and mode you played.
- Read the table. Every round of that mode is listed with payout and weight. Recompute the RTP, the share of rounds that pay nothing and the odds of the max win.
- Copy your seeds. In the casino's fairness settings, note your client seed, the hashed server seed and the nonce of the bet.
- Rotate the pair. Rotating reveals the old server seed. Hash it and compare it with the hashed value you saw before betting.
- Run the verifier. Enter both seeds and a nonce range. Each nonce gets a payout, and those should match your bet history line by line.
- Watch the replay. If you have the bet's replay link, it plays that exact round again.
Most players never touch the seeds, and you don't have to. The table is the part worth a minute before trying a new game. You'll see how many rounds pay nothing and how seldom the max win comes up in that mode. A bonus at 100x the bet on a 96% table gives back 96x per buy on average, and most single buys land below that because a handful of huge rounds carry the average.
What the checks leave open
- Whether the odds suit you. A verified 96% table still keeps about $4 of every $100 staked over a long run.
- What the casino does with your money. Provably fair covers the result of a bet. Deposits, withdrawals and account limits are outside it.
- How one session goes. The table gives odds per bet. Ten bets can land far above or far below the average.
- How a seed pair becomes a row. The public Engine docs describe the weighted draw. The exact step from seeds to row number sits inside the verifier, so you run it rather than recompute it by hand.
Seeds on Stake Originals work differently
Originals like Dice or Mines on Stake have no table of stored rounds. Their results are calculated on the spot from the casino's server seed, the player's client seed and a nonce that goes up by one with every bet. The server seed stays hidden behind its hash until the player rotates it. After that the plain seed is shown and can be hashed again to see that it matches.
| Stake Originals | Stake Engine slots | |
|---|---|---|
| Source of the result | Calculated from the seeds with a formula per game | A row drawn from the published outcome table |
| Who sets the odds | Stake, through the game formula | The studio, through the table weights |
| What you can recompute | Each result, from the seeds | Each mode's RTP from the table, each bet's payout through the verifier |
| Verifiers | Stake's fairness page and third-party sites | Engine fairness page, bonushunt.gg |
Originals: Stake's implementation and overview pages (archived copies in the sources). Engine: how the RGS picks a round and the Engine fairness page.
Picking a provably fair slot
Every Stake Engine game sits on that same system, so the label on its own says little about one slot versus another. Go by the table behind it: the mode's RTP, how often it pays anything and how the max win compares with the chance of hitting it. Our crypto slots list sorts checkable games by players, and the high RTP list sorts the same pool by RTP.
Beltastic is an Engine studio, and our game uses the same system. Not affiliated with Stake, Engine or bonushunt.gg. Game names belong to their owners.
Questions
Are provably fair slots really fair?
They're checkable. You can confirm that a result came from the published odds and wasn't changed after your bet. The odds still favour the casino, since every Engine table pays back less than 100% on average.
How does the Stake Engine verifier work?
You choose the game, version and mode, enter the client seed, the revealed server seed and a range of nonces, and it lists the payout for each nonce with a running balance and the RTP of the mode.
What is a nonce in provably fair?
A counter that goes up by one with every bet on the same seed pair. Each bet gets a new result without new seeds.
Can a casino change a provably fair result?
Not without it showing up. The server seed is fixed as a hash before you bet and the outcome table is public, so a changed result would not match when you run the check.
Sources
- Engine docs: How the RGS works. books, lookup tables, weighted random selection, stateless rounds Checked 12 November 2026
- Engine docs: math requirements. 100,000 to 1,000,000 simulations per slot mode Checked 12 November 2026
- Engine fairness verifier. inputs: game, version, mode, client seed, server seed, nonce range; outputs: payouts, running balance, mode RTP Checked 12 November 2026
- bonushunt.gg Engine explorer. reproduce outcomes from a seed pair via the Engine fairness API Checked 12 November 2026
- bonushunt.gg: how Engine ratings work. each mode ships as an outcome table, every spin or buy drawn from it with provably fair seeds Checked 12 November 2026
- Stake: provably fair implementation (Wayback, 26 Sep 2026). server seed, client seed, nonce, cursor; rotation reveals the server seed Checked 12 November 2026
- Stake: provably fair overview (Wayback, 2 Oct 2026). commitment scheme, all Stake Originals verifiable Checked 12 November 2026
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