Technique 3 of 8 · Core technique
Open a satisfied number's neighbours together
The guide and all minesweeper techniques
Minesweeper techniques
- 1Finding certain minesStart here
- 2Finding safe cellsStart here
- 3Flagging and chordingCore technique
- 4Comparing neighbouring numbersShared cells
- 5Subtracting known minesSimplifying clues
- 6The 1–2–1 patternRecognising patterns
- 7The 1–2–2–1 patternRecognising patterns
- 8Using the remaining mine countFinishing a board
Chording is a shortcut for opening the remaining neighbours of a revealed number. On Puzzled, tap or click the number once it has exactly its count in surrounding flags.
The game checks the flag count, not the reasoning behind your flags. A wrong flag can leave a mine unflagged, and chording then opens that mine. Prove the flags first.
Example 1: One flag makes a chord safe
Step 1 of 3
The lower-left 1 has only one covered neighbour. That cell must be a mine.
The lower-left 1 touches only the covered cell above it. Flag that certain mine first; this uses the basic counting rule.
The upper 1 then has its mine accounted for. Clicking it opens both remaining covered neighbours at once. The lower-middle 1 would make the same valid chord.
Work inside the solid frame. Every possible mine neighbour of these clues is inside it. Cells beyond the frame are background, not revealed zeros or extra clues.
Flags are proved mines. A tick marks a cell proved safe; its number is not shown.
Blue-ringed numbers are the clues to compare. Shading marks the cells being discussed.
Try it yourself
Try the reasoning yourself. Choose an answer to see the explanation.
Use this turned example to place the certain flag, then chord a satisfied number.
Practice only: no clock, saved game or hint charge.
Task 1 of 2: Flag the certain mine.
Choose a cell on the board.
Work inside the solid frame. Every possible mine neighbour of these clues is inside it. Cells beyond the frame are background, not revealed zeros or extra clues.
Practice close-up: rows 1–4, columns 1–4.
Flags are proved mines. A tick marks a cell proved safe; its number is not shown.
How to spot it faster
- Use a chord when several safe neighbours remain around a satisfied number.
- Check the flags' positions as well as their count.
- Flag mode changes covered-cell taps. Revealed numbers still chord, so you can flag and chord without switching modes each time.
Common mistakes
Using a chord to test a guess
A chord can hit a mine. It is an action based on your flags, not a way to ask whether those flags are correct.
Chording a number with nothing left to open
If every neighbour is already open or flagged, clicking the number changes nothing. Look for another part of the boundary.
Questions
Further reading
Try it
In solo play, prove a mine, flag it, and check which neighbouring numbers are now satisfied. Use a chord where it will open at least one cell.
Play solo Minesweeper