Minesweeper Rules — Complete Guide
Win Minesweeper by revealing every square that does not contain a mine. A number tells you how many mines touch that square, including diagonals. Use flags to mark mines you have identified; opening a mine ends the game.
Jump to standard board sizes and mine counts · Play Minesweeper
Try it yourself
Three small steps to your first clear
Practice without a timer, account or score. A wrong answer simply explains the next step.
Read a number
A number counts nearby mines, including diagonals. In this teaching diagram, two mines are already visible.
Further reading: game rules and pattern logic from World of Minesweeper.
The Board
A Minesweeper board is a rectangular grid of cells. Each cell is initially hidden. Beneath the surface, a fixed number of mines are distributed across the grid. In a new game outside the Daily challenge, the first cell you open is protected from mines. Daily boards instead begin with a fixed safe opening. The remaining safe cells either border at least one mine and display a number, or border no mines and display nothing (blank).
Standard Minesweeper board sizes
There are three standard difficulty levels. Beginner is 9×9 with 10 mines, Intermediate is 16×16 with 40 mines, and Expert is 30×16 with 99 mines. Dimensions below are columns × rows: the Expert board is 30 squares wide and 16 high.
| Level | Board size | Mines | Safe squares |
|---|---|---|---|
| Beginner | 9×9 | 10 | 71 |
| Intermediate | 16×16 | 40 | 216 |
| Expert | 30×16 | 99 | 381 |
For example, Beginner contains 81 squares: reveal all 71 safe squares to win. You do not need to flag all 10 mines. Custom mode lets you choose a different board size and mine count within the game's limits.
Mines
Mines are the hazards of the game. They are invisible until you either click on one (ending the game) or successfully complete the board (at which point all mine locations are revealed). The mine counter starts with the total mine count, then subtracts each flag you place.
A mine occupies exactly one cell. Mines do not "spread" or have blast radii — only the exact cell that contains the mine is dangerous. Clicking any safe cell adjacent to a mine simply reveals its number; only clicking the mine cell itself causes a loss.
Numbers
When you reveal a safe cell that is adjacent to one or more mines, the cell displays a number from 1 to 8. This number is the exact count of mines in the eight neighboring cells (horizontally, vertically, and diagonally adjacent). Numbers are the primary source of information in Minesweeper — all logical deductions flow from them.
Key principle: A number tells you the total mine count among all eight neighbors, not just the ones you haven't revealed yet. Only subtract mines you have already proved from that count. Revealing a safe neighbor does not reduce the mine count.
A blank cell (no number) means none of its eight neighbors contain a mine. Revealing a blank cell triggers an automatic cascade: the engine reveals all connected blank cells and their numbered borders simultaneously, potentially opening a large section of the board.
Flags
Right-clicking an unrevealed cell places a flag (🚩) on it. Flags are markers that communicate your belief that a mine is hiding there. They serve two purposes: they prevent accidental clicks on cells you've identified as mines, and they enable chording (see below).
The mine counter decrements by 1 for each flag placed, giving you a running tally of how many mines remain unaccounted for. Importantly, the game does not check whether your flags are placed correctly — you can flag a safe cell, and the counter will still decrement. Only winning or losing reveals the truth.
On some implementations a second right-click cycles through a question-mark state (?) before removing the flag. On this site, right-clicking toggles directly between flagged and unflagged.
Chording
Chording is an advanced mechanic that speeds up play significantly. When a revealed number cell has exactly as many adjacent flags as its number value, you can chord-click it to instantly reveal all remaining non-flagged neighbors.
For example: a "2" cell with two adjacent flags can be chorded to reveal its remaining neighbors in a single click. If all your flags on that cell are correctly placed, all revealed neighbors will be safe. If any flag is wrong (placed on a safe cell), the chord will detonate a mine and end the game.
This is why flag accuracy matters so much at higher levels. A misplaced flag can make a chord reveal a mine even when the flag count looks correct.
Win Condition
You win when every cell that does not contain a mine has been revealed. The game does not require you to flag all mines — only to clear all safe cells. When the last safe cell is revealed, the game ends immediately with a win, your timer stops, and your time is recorded as a personal best if it qualifies.
On a win, the remaining mines are automatically flagged. A safe cell left under an incorrect flag prevents a win until you remove the flag and reveal that cell.
Lose Condition
You lose the moment you reveal a cell containing a mine. The game ends immediately, regardless of how many safe cells remain. All mines on the board become visible, and the mine you clicked is highlighted to indicate your fatal click.
A loss triggered by incorrect chording (chording a number when a neighbor flag is misplaced) follows the same rule — an unflagged mine is revealed, and the game ends. The incorrectly flagged square itself is safe.
First-Click Safety Rule
In a new game outside the Daily challenge, this site places the mines after your first click, keeping that square safe. This protection also applies to custom games and No-Guess mode.
On standard boards this site also keeps the first square's neighbors free of mines, creating an opening. Very dense custom boards may have room to protect only the clicked square. Daily boards have a fixed opening; their next covered square is not automatically safe.
No-Guess Mode
Standard Minesweeper sometimes places mines in positions where the only way to proceed is to guess — a 50/50 situation with no additional logical information available. Skilled players accept these guesses as part of the game, but many players find them frustrating.
No-Guess mode searches for boards that the built-in solver can clear using logical deductions. Generation has an attempt limit; if it cannot find one, the game identifies the fallback as a standard board that may require guesses. Successfully generated No-Guess boards are selected for solvability, so their times should be compared with other No-Guess times.
Timer
The timer starts on your first click and stops the moment you reveal the last safe cell (win) or click a mine (loss). Time is displayed in seconds to two decimal places. The official measure of skill in competitive Minesweeper is time, though derived metrics like 3BV/s (board complexity per second) and efficiency are also tracked on the leaderboard.
Now that you know the rules — put them to use
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