Minesweeper tips: from guessing to winning

Every fact lives in the numbers: a number claims exactly N mines among its eight neighbours (five on edges, three in corners). Reasoning always watches two quantities: the unrevealed neighbours of a number, and the mines already accounted for. Three instant corollaries:

• A number N with exactly N unrevealed neighbours → all of them are mines. Flag everything.
• Flagged neighbours already equal N → every other neighbour is safe. Chord it.
• Two adjacent numbers differing by 1, where the larger has exactly one extra unrevealed neighbour → that square is a mine.

These three resolve most of the board. The rest falls to patterns.

1-2-1 (three numbers in a row along a wall)

Three adjacent numbers on a board edge read 1, 2, 1. Call their hidden neighbours a, b, c. The left 1 says exactly one mine among {a, b}; the 2 says exactly two among {a, b, c}; the right 1 says exactly one among {b, c}. Adding the two 1s: exactly two mines across {a, b, c} — which fully satisfies the 2, and b cannot be a mine (that would force both 1s over budget). So a and c are mines.

The mnemonic: 1-2-1 — flags on the outside, open the middle.

1-2-2-1

Same method, one step longer: when 1, 2, 2, 1 sit along a wall, the outer two squares are safe and the inner two are mines. Sum the two 1s, let the two 2s absorb the rest. Variants like 1-2-2-2-1 resolve the same way — derive them on the spot.

Expert boards almost always force a probabilistic decision eventually. Three principles:

1. Exhaust certainty first. Clear every forced square before counting odds — many "guesses" dissolve once the rest of the board moves.
2. Compare mine densities. Count remaining mines ÷ unrevealed squares per candidate region; start where the density is lowest.
3. Preserve the inference chain. If you must guess, guess where being wrong does not sever a large region — adjacent to opened ground, not mid-island.

Finally, tempo: chording is a scalpel, not a habit. On intermediate and below, chord freely where flags are certain; on expert, only chord regions you just verified 100%.

Understanding a pattern and using it are different skills. Open our Minesweeper on intermediate and make it a drill: every time you meet a number row along a wall, stop and derive before you chord. Two weeks of that and it is muscle memory.

For the native Windows version, see the guide: classic Solitaire & Minesweeper on Windows 11.