Mines is played on a 5 × 5 grid. You choose how many mines are hidden, place a bet and open tiles one by one. Every safe tile raises the cash-out multiplier; one mine ends the round and takes the stake. With money riding on every tap, you need to know the casino cannot move mines mid-round or bias tiles against you. That is what provably fair cryptography is for, the same approach used in crypto Dice, Plinko and Limbo.

Mines uses a square board of 25 tiles. The player names a mine count before the first tap. A higher mine count raises the multiplier on each safe tile. The same count also raises the chance that the next tile ends the round. The cash-out control locks the current multiplier and returns the stake times that multiplier. A mine pays nothing for that round. The layout decision happens before the bet is accepted. A later tap only reveals a tile that the seed already assigned.

The commitment scheme in plain English

  • Server seed: before the round, the casino's server generates a random server seed, which decides the mine layout.
  • Hash disclosure: the server seed is run through a one-way hash function, usually SHA-256, and only the hash is shown to you. A SHA-256 hash is 64 characters long. Because hashing cannot be reversed or faked, the server cannot change the seed without changing the hash.
  • Client seed: your browser or app supplies a client seed, which you can often edit. The two seeds, plus a round counter called a nonce, are combined to fix which of the 25 tiles hide mines.

Think of the hash as a sealed envelope: if the contents change, the seal no longer matches.

The server seed is a long random string the casino generates. SHA-256 turns that string into a 256-bit digest, printed as 64 hexadecimal characters. The digest is public. The seed stays hidden until the player rotates the seed pair or the game reveals it after the round. A one-way hash has no practical reverse. Seeing the digest does not reveal the seed. The client seed is a string the player's device sends, and many games let the player type a new one. The nonce is an integer that increases by one for each round under the same seed pair. Those three values feed the function that picks mine positions. The casino alone does not choose the map, because the client seed is part of the input.

Reading the hash and the seeds

The hash on the fairness panel is a fingerprint of the server seed, not of the mine map itself. Its job is to fix the seed before the round starts. The map is derived from that seed, so a commitment to the seed also commits the casino to the layout. A full SHA-256 value is 64 hexadecimal characters, and two different seeds should not produce the same value in practice.

The client seed works differently. It is the input you can influence, and it enters the calculation next to the server seed. The casino fixes its seed first, so a new client seed changes the result only in the way the game documents. Read the fairness page for the order in which the inputs are combined. If that page does not say how the seeds combine, you cannot repeat the check on your own.

The nonce is the third input. It is a counter that increases with each round under one seed pair. Recording the nonce with each round lets you check one specific bet instead of the whole session. Together, the server seed, the client seed and the nonce are the values the game needs to reproduce a round.

How to verify a round, step by step

  1. Copy the server seed revealed when the round ends, or when you rotate to a new seed pair.
  2. Hash it with any SHA-256 tool. Many casinos link one in the game.
  3. Compare the result with the hash you were shown before your first tap.
  4. If it matches, the mine map was fixed from the start.
  5. If it does not match, the round was altered, which is exactly what the system is designed to expose.

Most games wrap these steps in a single Verify button, which works fine in a mobile browser. Knowing the manual process means you do not have to trust that button.

Open the fairness panel before the round and copy the published hash. Play the round, or rotate the seed pair. Paste the revealed server seed into a SHA-256 calculator that you control. Compare the two digests character by character. A match means the seed that produced the map is the seed the casino committed to. A mismatch means the published commitment and the revealed seed describe different inputs. Record the client seed and the nonce beside the hash so a later check uses the same inputs.

Checking the client seed and nonce

Use the same client seed and the same nonce that the game lists for the round you want to check. A small mismatch, such as a stray space or a changed capital letter, produces a different result, so copy the values rather than retyping them.

Keep a short record for each session: the date, the hash shown before play, the client seed, and the nonce for each round. When a round looks wrong, the record lets you run the check later without relying on the screen you saw at the time. If the round rules are new to you, the Mines how-to guide explains the mine count and cash-out steps first.

Changing the client seed during a session starts a new seed pair. Note the point where the change happens, because rounds before and after it belong to different commitments.

Can the casino change mines during a round?

A common worry is that the game could let you hit a few safe tiles, then move the mines. In a provably fair game that is not possible, because all 25 outcomes are tied to the seed hash you saw before the round. When you open a tile, the game reveals what was already set; it does not roll again. If the casino moved a mine, the revealed seed would no longer produce the layout you played, and the check would fail.

Each tile is a position in a list the seed already ordered. Opening tile 7 reads position 7. The tap does not draw a new random number. The remaining tiles keep the labels they had at the start. A casino that swapped a mine onto a tile the player was about to open would need a different seed. That different seed would hash to a different digest. The digest stored before the round would fail the comparison.

What a verified round does not prove

A matching hash shows that the mine map was fixed before the round. It does not show that the game is fair in every other sense. The check covers one link in the chain, which is the seed that produced the layout. It does not cover the payout table, the multiplier curve or the operator's terms.

Verification also depends on the casino publishing the right data. If the seed reveal is delayed, or the hash shown before the round is missing, there is nothing to compare. A missing commitment is a warning sign, not a neutral gap. Look for the commitment in the game before you bet, not after a loss.

Fairness and the house edge are separate questions. A game can be provably fair and still return less than the stake over time. Verification tells you the layout was not changed. It does not tell you the layout favours you.

Hash maths in action: a short example

  • Server seed: f9d0…2a1 (hidden until the round ends)
  • SHA-256 hash: cd15bfa…e907 (shown before the round)
  • Client seed: user123
  • Result: the combined seeds produce the mine map. After the round, you hash f9d0…2a1. If you get cd15bfa…e907, the seed was not changed.

Changing even one character of the seed, such as making one letter a capital, produces a completely different hash. That is why any tampering shows up at once.

The short example uses truncated strings so the page stays readable. A real server seed is much longer. A real SHA-256 digest is 64 hex characters. Truncation is only for display. The check uses the full seed and the full digest. One changed character anywhere in the seed changes the digest. The new digest does not resemble the old one in a useful way.

If you still doubt the numbers

  • Change your client seed each session. The server cannot know it in advance, so it cannot plan a layout around it.
  • Use an independent hash tool, for example openssl dgst -sha256 in a terminal, instead of the casino's own checker.
  • Check for licensing and testing. Play at licensed casinos, and look for independent test reports where the casino or studio publishes them.

Set a client seed you can remember, then leave it in place for several rounds. Each round still changes because the nonce increases. Copy the hash at the start of the session and keep it in a note outside the casino app. An independent checker removes the casino's Verify button from the trust chain. A licence and a published test report answer a different question. They describe the operator and the studio, not one round's seed.

Treat a single successful check as a sample, not a guarantee for the whole account history. Record the hash, seed pair and nonce for a few sessions, then repeat the check on a few rounds from each. A consistent pattern across sessions is more useful than one verified round.

Other games with the same fairness system

Mines is not the only game with this model. If you trust the provably fair model in Mines, you will find the same seed and hash system in Dice, Plinko, Limbo, crash games and CoinFlip. Each one fixes the outcome before your bet and lets you verify it afterwards. Once you know the check in one game, you can use it across the instant games range.

Dice, Plinko, Limbo, crash games and CoinFlip reuse the same three inputs. The output is a number, a path, a multiplier or a coin side, instead of a mine map. The check is the same. Hash the revealed server seed and compare it with the digest shown before the bet. Learning the check once covers the rest of that instant range.

Fair does not mean profitable

Provably fair maths proves the results were not rigged. It does not tilt the odds your way, and the house edge still applies to every round. Set a stop-loss (for example, 20% of your session bankroll) and a stop-win (for example, bank your stake once you are 50% up), and take breaks, especially when you move from low-mine boards to high-risk ones. Our responsible gaming page lists the limit tools to look for.

The house edge is the share of each stake the game keeps over a large number of rounds. A verified seed does not change that share. A stop-loss of 20 percent of the session bankroll ends the session after that loss. A stop-win of 50 percent banks the stake plus half of it and ends the session. High mine counts make single rounds swing harder. Short breaks between those boards keep the session inside the limits you set.

Losses come from the stake and the house edge, not from a hidden move in the layout. Session limits work against both. Look for deposit limits, session timers and reality checks in the account settings before you start.

A useful rule is to decide the stop-loss and stop-win before the first round, then keep to them. Raising the mine count to win back a loss is the usual way a short session becomes a long one.