Minesweeper Strategy & Tips

Start Smart: Openings Matter

On boards where the first click only protects its own square, corners historically give the best odds of a big cascade. On Web Minesweeper the first click is always fully safe, so instead focus on the second decision: after your opening cascade, resolve the numbers along the edges of the opened area first. Edge numbers touch fewer covered squares, so they yield more certainty per clue.

The Core Skill: Counting Flags and Mines

Every deduction in Minesweeper comes from one sentence: the number equals the mines among its neighbors. When a number's remaining covered neighbors are exactly as many as the mines it still needs, all of them are mines. When its flags already satisfy it, all remaining neighbors are safe. Train yourself to ask two questions at every number:

• How many mines does this number still need?
• How many covered squares does it still touch?

Essential Patterns

Certain number combinations appear constantly. Learning to spot them on sight eliminates most of the board's hard thinking. In the diagrams below, digits are revealed numbers, X marks a proven mine, and · marks a proven safe square.

The 1-1: a mine at the junction

1 1 1
· X ·

Two adjacent 1s sharing covered squares: the shared square at the junction is the mine. Everything else those 1s touch is safe.

The 1-2: guaranteed mine and guaranteed safe

1 2 2 1
· X · X ·

The 1-2 pair is the workhorse of Expert boards. Read from the side: the square next to the 1 (on the far side from the 2) is safe, and the square only the 2 needs is a mine. The full 1-2-2-1 row hands you two mines and three safe squares at once.

The 1-2-1 and 2-1-2 walls

1 2 1
X · X

When a 1-2-1 sits against a wall of covered squares, the mines sit under the 1s and the center is safe. Flip it for the 2-1-2: mines under the 2s, safe under the 1s.

Reduce before you read

A scary 4 with two flags already around it is just a 2. Mentally (or with flags) subtract satisfied numbers first, and most boards collapse into the simple patterns above.

Use Flags as Pencil Marks

Flags are memory. Flag a proven mine the moment you deduce it — unproven candidates should stay unflagged so they don't pollute your reads. If you enjoy precision play, a common habit is to chord aggressively: whenever a number is satisfied, double-click it instead of opening neighbors one by one.

When Guessing Is Actually Correct

Sometimes the math leaves a genuine coin flip — for example, two squares that must contain exactly one mine with no way to tell which. When you must guess:

• Guess early, not late. If a forced guess exists, taking it while the rest of the board is unresolved wastes less of your work if you lose.
• Count the odds. Prefer the square with the lower mine probability; corners and edges often carry less risk than the raw numbers suggest because they touch fewer squares.
• Never guess when deduction remains. Scan the whole border of the open region before concluding you are stuck — the answer is usually hiding in a number you haven't read in a while.

A Practice Ladder That Works

1. Beginner (9×9) until you win most games without hints — this wires in the basic patterns.
2. Intermediate (16×16) to practice holding multiple clues in your head at once.
3. Expert (30×16) for reading long walls of numbers — this is where 1-2-2-1 and friends earn their keep.
4. Then chase the clock: strong players finish Expert in under 200 seconds; the world's best dip under 40. Curious how they do it? Read Inside Minesweeper Speedrunning.