How Mines Multipliers Are Calculated
5 min read
The multiplier in Mines can feel mysterious — it ticks up by a different amount every time you reveal a tile. But it isn't arbitrary at all. It comes from one simple idea: the rarer an outcome is, the more it pays. Here is the exact maths.
The setup
A Mines board has N = 25 tiles. You choose m mines, which leaves 25 − m safe tiles. Each time you reveal a safe tile, the game asks: “how unlikely was that?” and pays you the inverse.
The formula
After revealing k safe tiles, the fair multiplier is the product of (N − i) ÷ (N − m − i) for i = 0, 1, … , k − 1. SatoshiMines then multiplies by 0.99 to apply a flat 1% house edge.
Each factor is just tiles remaining divided by safe tiles remaining. As safe tiles run out, that fraction grows, so later tiles add more to the multiplier than earlier ones.
A worked example (3 mines)
With m = 3 mines there are 22 safe tiles. Watch the fair multiplier build:
| Tiles revealed (k) | Calculation | Fair multiplier | Win chance |
|---|---|---|---|
| 1 | 25 ÷ 22 | 1.14× | 88.0% |
| 2 | × 24 ÷ 21 | 1.30× | 77.0% |
| 3 | × 23 ÷ 20 | 1.49× | 67.0% |
After the 1% edge, those show in-game as roughly 1.13×, 1.29× and 1.48×. Notice the win chance is exactly the reciprocal of the fair multiplier: 1 ÷ 1.14 ≈ 0.88. That is not a coincidence — a fair game pays you the inverse of your probability of getting there.
Why the house edge matters
The 0.99 factor is the only thing standing between you and a perfectly break-even game. It is small per round but constant, which is why no betting pattern can overcome it in the long run. It is the same 1% on every round, every mine count — fully transparent.
Want to try any combination? Plug numbers into the Mines calculator or read the strategy guide.
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