Minesweeper Cheat Sheet
Every formation that solves itself, the numbers, and the specs — on one page. In each diagram the revealed numbers sit on the top row and the answer for the covered cells beneath them. All of it is verified by exhaustive enumeration, not by convention.
Patterns that solve themselves
1-2-1 along a wall
Mines under the two 1s; the cell under the 2 is safe. A mine in the middle would satisfy both 1s at once and leave the 2 one short.
1-2-2-1 along a wall
The inverse of the 1-2-1: mines under the two 2s, safe under the end 1s. Resolves two mines and two safe cells at once.
2-1-2 (needs a wider row)
Impossible over only three covered cells. Over five: mine under the middle 1 and at each far end, safe under both 2s.
1-1 along a wall
Both 1s share the same mine, so any cell touching only the second 1 — the one past it — is safe. The fastest way to open a wall.
1-2 at a border
The 2 needs one more mine than the 1 can account for, and only one cell is unique to it. That far cell is a mine.
Corner and edge counts
A corner cell touches 3 neighbours, an edge cell 5, an open cell 8. A 3 in the corner means all three are mines.
The numbers
| Digit | Colour | Means | How common |
|---|---|---|---|
| 1 | Blue | 1 adjacent mine | Most frequent clue on every board |
| 2 | Green | 2 adjacent mines | Backbone of the 1-2 and 1-2-1 patterns |
| 3 | Red | 3 adjacent mines | Common on Expert; often locks a whole edge |
| 4 | Dark blue | 4 adjacent mines | Half the neighbours; usually a dense cluster |
| 5 | Maroon | 5 adjacent mines | Rare outside Expert |
| 6 | Teal | 6 adjacent mines | Uncommon; strongly constrains everything near it |
| 7 | Black | 7 adjacent mines | Rare enough to be worth a screenshot |
| 8 | Grey | All 8 neighbours are mines | The rarest cell in the game |
There is no 9 and there cannot be: a cell has at most eight neighbours.
Boards and benchmarks
| Board | Grid | Mines | Density | Above average | Strong | Elite |
|---|---|---|---|---|---|---|
| Beginner | 9 × 9 | 10 | 12.3% | < 120s | < 60s | < 30s |
| Intermediate | 16 × 16 | 40 | 15.6% | < 300s | < 150s | < 80s |
| Expert | 30 × 16 | 99 | 20.6% | < 200s | < 100s | < 60s |
Metrics worth knowing
| Term | Definition |
|---|---|
| 3BV | Minimum left clicks to clear a board with perfect play. Each opening counts once, plus every safe cell outside an opening. |
| 3BV/s | 3BV divided by your finishing time. What competitive players compare instead of raw seconds. |
| Efficiency | 3BV divided by clicks actually used, as a percentage. Chording can push it above 100%. |
| Chord | Both buttons on a fully-flagged number opens every remaining neighbour at once. |
| Flagless | Clearing with no flags at all. Saves up to 99 clicks on Expert but forfeits chording. |
| True 50/50 | Two covered cells, one mine, no clue separating them. Genuinely unsolvable. |
Work out a board's 3BV with the 3BV calculator, check where a time places with Is My Time Good?, read the full reasoning in the pattern guide, or start from the rules.