Counting the mines
At the end of a game, the mine counter tells you how many mines are left. Sometimes that decides cells no number can.
The counter shows the mines still hidden. When the numbers need all of them in some of the hidden cells, the other hidden cells are safe, even those no number touches. The board here holds every hidden cell of the game, so the counter is about these cells only.
How it works
The numbers alone decide no cell here. Look at the mine counter.
Your turn
Each board is a real position from a game. Tap or click to open; right-click, long-press or switch on Flag to place a flag. If you are not sure, take a hint: the first one only shows where to look.
Which hidden cells can you be sure of?
How the exercises were chosen
A computer checked every board: in what you see, the numbers prove nothing even all together; only with the mine counter do the safe cells follow.