What is chording in Minesweeper?
Chording opens the unflagged neighbors of an already revealed number when the number of adjacent flags matches that number. In this game, click or tap the open number to chord. It is safe only when the flags actually mark the mines.
For example, a 2 touching two correctly flagged mines has no other neighboring mines. A chord opens its remaining covered neighbors together. It applies the same logic as opening each one yourself.
On this site, clicking an open number works in both Reveal and Flag mode. With a keyboard, move to the open number with the arrow keys and press Enter or Space.
Place a flag only when the clues support it
Right-click a covered square on a computer, press F while it has keyboard focus, or choose Flag mode and tap it. On a touchscreen, you can also press and hold a covered square.
The default mark cycle is covered → flag → question mark → covered. Repeat the marking action to move through that cycle. Turn off Options → Marks (?) if you prefer flags to toggle directly on and off.
A question mark is a reminder that you are uncertain. It does not count as a flag, and it does not protect a square from being opened by a chord. Use a flag for a proven mine; leave an unresolved square covered or question-marked.
If you are unsure what makes a flag certain, try the two-move beginner exercise before learning this shortcut.
Try it: one number, six safe squares
This prepared board has two mines, both correctly flagged. The center is the only open square. Use it to clear the rest.
Clear six squares with one click
Both flags are correct. The open 2 in the center counts them, including the diagonal mine in each top corner.
Step 1 of 1
Select the open 2 to reveal all six unflagged neighbors at once.
Select squares to answer the prompt. Mistakes are safe here.
Read the solution and reasoning
- The 2 touches exactly two correct flags. Chording opens A through F together because none can be another mine.
A matching flag count enables a chord; correct flag locations make it safe. In the real game, a misplaced flag can make a chord open a mine.
Why can chording open a mine?
The game checks the number of flags, not whether your deductions are correct. If a 2 touches two flags but one is on a safe square, there may still be an unflagged mine next to it. Chording can open that mine and end the game.
In the practice board, imagine moving the top-right flag to the top-middle square. The count is still two, but the top-right mine is now unflagged. A chord would open it.
If the flag count does not match, this version leaves the surrounding squares closed. Check for missing or extra flags, and count diagonal neighbors too. An open blank has no number to chord.
Controls at a glance
| Action | Mouse or touch | Keyboard |
|---|---|---|
| Reveal | Click or tap in Reveal mode | Enter or Space |
| Mark a square | Right-click, hold, or tap in Flag mode | F |
| Chord | Click or tap an open number | Enter or Space on an open number |
| Move focus | Select a square | Arrow keys |
| New game | Smiley button or Options → New | F2 |
Keyboard Enter and Space always reveal or chord, even when Flag mode is selected. F always marks a square. Other Minesweeper versions may use a different shortcut for chording, so these controls describe this site specifically.
Return to the game and try a chord after making your first certain flags.