How to play Minesweeper: numbers, flags and safe deductions

Where the game came from

Many players recognise Minesweeper from Windows, but the genre’s history and one particular release are different things. Microsoft’s own timeline records an Entertainment Pack containing MineSweeper on 8 October 1990. This is a documented milestone in its distribution, rather than proof that no earlier mine-finding games existed.

What the numbers mean

An opened number tells you how many mines occupy its eight neighbouring cells, including diagonals. Edge cells have fewer neighbours. Win by opening every safe cell. A flag is your note about a suspected mine; the flag itself does not prove that the cell is dangerous.

In Rich Games, the first click is safe and reveals a starting area. The regular boards are 7×7, 8×8 and 9×9. A switch changes between opening cells and placing flags. Tapping a number opens its remaining neighbours when the surrounding flag count matches its clue, so verify those flags first.

Two basic rules, then compare regions

If you have identified all the mines around a number, its other unopened neighbours are safe. If the number of missing mines equals the number of unopened neighbours, every one of those neighbours is a mine. Account for confirmed flags before applying either rule.

When direct deductions run out, compare the sets of unopened cells around nearby clues. If one set is contained in another, subtract the smaller region’s mine count. The difference tells you how many mines occupy the remaining cells. You are comparing constraints, rather than memorising a visual pattern without understanding it.

Worked example: one safe cell from two clues

Suppose that, after accounting for all other neighbours, the left clue requires exactly one mine in cells A and B. The right clue requires exactly one mine in A, B and C. Cell C must be safe: the shared pair A–B already contains the larger region’s entire mine allowance.

If the second clue instead required two mines in A, B and C, then C would be a mine. You still would not know which of A and B contains the other mine, but that uncertainty does not prevent a definite conclusion about C.

Common mistakes and risky shortcuts

Diagonal cells count too. Missing one diagonal neighbour changes the constraint completely. Avoid flagging by intuition and then treating that flag as proof: one guess can otherwise generate several false safe cells.

Opening a mine ends a regular Rich Games game. In Daily, hitting a mine counts as a mistake, play continues, and a time penalty is added. Do not assume that Daily’s behaviour also applies to the regular mode.

Practise reading a board

Begin on easy and state the reason for every move: “two unopened cells and two missing mines”. Next, try medium and search for pairs of nested regions. On hard, bring the total number of remaining mines into your reasoning as well.

If you get stuck, scan the entire boundary of the opened area instead of staring at one awkward pair. Revisiting an overlooked clue often reveals another safe move. Speed follows accurate reading of the constraints.