Minesweeper strategy and techniques

Three rules solve every field on this site

Minesweeper has a reputation for luck, which is only true of fields nobody checked. Every field here is verified by a solver that uses exactly the three techniques below, so the three of them are provably enough — there is no fourth technique to learn and no position where you need one.

They are listed in the order you will actually need them.

1. The field rule

For a single number, compare its value with the flags and covered squares around it:

• value = flags around it → every remaining covered neighbour is safe.
• value − flags = covered neighbours left → every one of them is a mine.

This finishes most of an easy field on its own. It is also the rule you apply hundreds of times per expert field, so make it automatic before worrying about anything else.

2. The subset rule — where the patterns come from

Take two numbers whose covered squares overlap. If the covered squares of number A are a subset of those of number B, then the difference B − A must contain exactly B.remaining − A.remaining mines.

Two consequences do all the work:

• The difference needs zero mines → every square in it is safe.
• The difference needs as many mines as it has squares → all of them are mines.

The famous patterns are just this rule pre-computed:

• 1-2-1 along a wall — mines sit under the two ones, the middle square under the 2 is safe.
• 1-2-2 at an edge — the mines are under the twos.
• 1-1 in a corridor — the square past the second 1 is safe.

Learn the shapes if you like, but the rule underneath is what covers the cases that do not look like a named pattern.

3. The mine counter

The counter is a constraint on the whole field, not on one number, and that is precisely why it solves positions the first two rules cannot see:

• Flags placed = total mines → every covered square left is safe.
• Covered squares left = mines left → all of them are mines.

Late in a hard or expert field this frequently resolves an entire region in one step. Players who ignore the counter lose fields that were already solved.

Speed, once accuracy is there

• Flag, then chord. Chording is the only move that opens several squares at once. Everything else in your technique is preparation for it.
• Work along the frontier. The boundary between opened and covered squares is where all the information lives; jumping across the field re-reads numbers you have already read.
• Do not leave resolvable positions behind. Returning to them later means paying for the same reading twice.
• Learn the shapes, not the coordinates. Recognising 1-2-1 instantly is worth more than any keyboard trick.
• Use the keyboard on a desktop. Arrows to move, Enter to open, F to flag — no cursor travel between corners of the field.

Where the technique stops mattering

At some point your time is limited by how fast you can read numbers, not by which rule you know. That is the point at which the daily challenge becomes the interesting one: everybody plays the identical field, times are measured on the server, and the leaderboard tells you exactly where reading speed puts you in the world.