Minesweeper Rules

The object of Minesweeper is to reveal every cell that does not contain a mine. You do not have to find the mines, mark them, or do anything with them at all — clearing everything else is the win condition. Every number you uncover counts the mines in the eight cells touching it, diagonals included, and that one rule generates the entire game.

The board

A board is a grid with a fixed number of mines hidden in it. Three sizes are standard, and the ratio of mines to cells — the density — is what actually determines difficulty:

Difficulty	Grid	Cells	Mines	Density
Beginner	9 × 9	81	10	12.3%
Intermediate	16 × 16	256	40	15.6%
Expert	30 × 16	480	99	20.6%

You can also set your own dimensions on the custom board, which uses the same rules and the same engine.

What the numbers mean

A revealed cell shows a digit from 1 to 8, or nothing at all. The digit is the count of mines in the eight cells immediately surrounding it. A blank cell means zero adjacent mines, and blanks cascade: revealing one automatically reveals its neighbours, which is why a lucky first click can open half a board.

Number	Colour	Meaning
1	Blue	One mine in the surrounding eight cells
2	Green	Two adjacent mines
3	Red	Three adjacent mines
4	Dark blue	Four adjacent mines
5	Maroon	Five adjacent mines
6	Teal	Six adjacent mines
7	Black	Seven adjacent mines
8	Grey	All eight neighbours are mines

There is no 9, and there never can be: a cell has at most eight neighbours, so 8 is the ceiling. Position matters too — an edge cell has only five neighbours and a corner cell three, so a 3 in the corner means every single neighbour is a mine, while a 3 in open ground means three out of eight.

The three actions

Reveal

Left click. If the cell holds a mine, the game ends. If it holds a number, that number appears. If it is blank, it and its whole connected empty region open at once.

Flag

Right click places a marker on a cell you believe holds a mine. Flags do nothing mechanically — they neither protect you nor count toward winning. They are bookkeeping, and they exist so you can chord. The mine counter in the corner simply subtracts your flags from the total mine count, so it goes wrong if you flag incorrectly.

Chord

Click both buttons at once on a revealed number whose adjacent mines are all already flagged, and every remaining neighbour opens in a single action. One chord can replace up to eight separate clicks, which is why it is the largest speed gain in the game. Chording a number whose flags are wrong will open a mine and end the run, so it is only as safe as your flagging.

Winning and losing

Because flagging is irrelevant to the win condition, competitive players often skip it entirely. On an Expert board that saves 99 clicks. The trade-off is that you cannot chord without flags, so the fastest approach is usually a hybrid: flag only where a chord is about to pay for it. The flagless guide covers when each approach wins.

The first click

On Minesweeper.now the board is generated after your first click rather than before it, so that click can never be a mine and normally opens a sizeable region. Not every implementation does this — older Windows builds would happily let your opening move be a number with nothing around it, or a mine outright. That single difference is most of why the classic game has a harder reputation than Google's version, despite the two using identical boards and identical mine densities.

When logic runs out

Standard Minesweeper can produce positions that no amount of reasoning resolves: two covered cells, one mine between them, and no clue anywhere that separates them. That is a true 50/50, and it is genuinely a coin flip. Most positions that look like one are not, so read the whole board before guessing — the pattern guide covers the formations that resolve what appears unsolvable. If you would rather never face the coin flip at all, No-Guessing mode verifies every board is solvable by pure logic before it is dealt.

Common rule mistakes

• Thinking you must flag every mine to win. You never have to place a single flag.
• Trusting the mine counter. It only subtracts flags from the total; misflag three cells and it lies to you by three.
• Reading numbers one at a time. Numbers constrain each other. A 1 and a 2 side by side say far more together than separately.
• Forgetting diagonals. Adjacency is all eight surrounding cells, not the four orthogonal ones.
• Chording on unverified flags. A chord trusts your flags completely and will detonate a mine without hesitation.

Frequently asked

What are the rules of Minesweeper?

Reveal every cell that does not contain a mine. Each number you uncover counts the mines in the eight cells touching it, diagonals included. Reveal a mine and the game ends; clear every safe cell and you win. You never need to flag anything.

Do you have to flag all the mines to win Minesweeper?

No. The game is won when every non-mine cell is revealed. Flags are optional bookkeeping and the fastest players use none at all.

Can the first click in Minesweeper be a mine?

Not on Minesweeper.now. The board is generated after your first click, so that click is always safe and normally opens a large region to start from.

Ready to use them? Start on Beginner, print the cheat sheet, or read the pattern guide to stop guessing.