Guides

Minesweeper strategy

Most boards can be solved by a handful of rules applied carefully.

Rule 1: the number equals the covered cells

If a 3 has exactly three covered cells around it, all three are mines. Flag them. This is the most common deduction, and it often chains: the new flags change the neighbors' counts.

Rule 2: the flags already satisfy the number

If a 2 already has two flags around it, every other covered cell around it is safe. Open them, or chord on the number.

Rule 3: compare two numbers

If the covered cells of one number are a subset of the covered cells of another, the difference in their counts must sit in the extra cells. For example, a 1 whose covered cells are A and B, next to a 2 whose covered cells are A, B and C, tells you that C is a mine.

Edge patterns

• 1-2-1 in a row along a flat edge: the covered cells next to the two 1s are mines, and the covered cell next to the 2 is safe.
• 1-2-2-1 in a row along a flat edge: the covered cells next to the two 2s are mines, and the cells next to the 1s are safe.

Good habits

• Work the whole boundary of the opened area before guessing.
• Flag mines as you find them. It keeps the counts honest and makes chording possible.
• When you must guess, use the probability guide to pick the safest cell.
• Corners and edges have fewer neighbors, so they are often easier to resolve.