Minesweeper Strategies & Tips

Two rules to use before any pattern

First, subtract only mines you have proved from a clue. If a 3 touches two confirmed mines, it needs one more among its other covered neighbors. A flag is a reminder of that proof, not proof by itself.

If the remaining mine count equals the number of remaining covered neighbors, all those neighbors are mines. If the remaining mine count is zero, all those neighbors are safe.

On this site, standard boards protect the first square and its neighbors. Very dense custom boards may protect only the first square. The size of the opening varies; no opening percentage is guaranteed.

Understand the overlap

1-1: the extra square is safe

Suppose one 1 touches only covered squares A and B. Another 1 touches A, B and C, with all other neighbors known safe. A and B already contain the one mine both clues need. C must be safe.

1-2: the extra square is a mine

Now suppose the second clue is a 2. A and B contain exactly one mine, while A, B and C must contain two. The additional mine must be C. This alone does not tell you whether A or B is the other mine.

1-2-1: mines at the ends, safe in the middle

For a straight row of clues 1-2-1 bordering exactly three covered squares A, B and C, the left clue sees A and B, the center sees all three, and the right sees B and C. With no other unknown neighbors, A and C are mines and B is safe. The interactive exercise above shows why.

Check the surrounding squares before applying a pattern. Extra covered neighbors or incorrectly flagged mines change the constraints. When subtracting confirmed mines from larger clues, the same reasoning can reveal a hidden 1-2-1.

Flags, chording and the mine counter

A chord opens the unflagged neighbors of a revealed clue when the number of nearby flags matches that clue. It is safe only when those flags are correct. One wrong flag can expose an unflagged mine.

The mine counter is the board's mine total minus the flags you placed. A zero counter does not validate those flags. Only when every flag is proved correct can you conclude that all other covered squares are safe.

Flags are optional. You can win by opening every safe square without placing any. Choose the style that helps you reason clearly; speed is optional too.

When logic does not choose a square

Standard boards can contain genuine guesses at any difficulty. Before guessing, scan another edge, combine nearby clues and consider the total remaining mines. If multiple mine layouts still fit all the information, a local pattern may not identify a safe move.

No-Guess mode searches for a board our solver can complete using deductions. If generation cannot find one within its attempt limit, the game marks the fallback as a standard board. A No-Guess board can still require a deduction you have not learned yet.

Improve at your own pace

Try to explain one move before making it. After a loss, check which clue or flag led to the mistake. When Beginner feels comfortable, try Intermediate; you do not need a fast time or a daily streak to progress.

If you enjoy measuring speed, 3BV counts the minimum clicks to clear a board without flags, and 3BV/s divides that value by elapsed seconds. It describes board-clearing speed; it is not a probability of winning. Different sites can use different efficiency formulas.

Further reading: the World of Minesweeper guides to pattern deductions and gameplay and 3BV. The examples on this page use their own small boards.