# Is this minesweeper board inconsistent?

In the above game, look at the cell circled in red. It says 1, which means it must have only one neighboring cell which will have a mine. However, there are two cells which have mines surrounding this cell, circled in blue.

How is this possible? Is this board inconsistent, or have I misunderstood the rules of the game?

• 11 upvotes and over 2000 views in 8 hours for mine sweeper. Heck, I'm not even mad. That's amazing!
– RLH
Oct 11, 2018 at 12:38
• @RLH It is minesweeper, everyone can relate. Once it hit HNQ there is no stopping it. :D Oct 11, 2018 at 14:53

The board is consistent, but your logic is flawed: you've added a flag to a non-mine space. That's what this crossed out mine means:

Incidentally, the mine with a red background is the one you triggered. Other mines that are displayed at the end of the game are ones that you haven't flagged yet. The remaining flags were correct - they mark the space of a mine.

I assume the board area looked similar to this before you clicked (you'll have to excuse the quick MS paint mock-up):

Yellow arrows represent 'solved' mines. Purple diamonds represent safe squares (the '2' above them already has two mines associated with it) so that just leaves the question marks as the 'unknowns'.

Note the '2' in (R6,C7) already has one solved mine (which you correctly flagged) next to it at (R6,C6). This means that the clicked mine (red background) and the mis-flag (crossed mine) could not both be mines:

From the position of the '2' and '1', both of those squares had an equal chance of containing a single mine, thus they weren't logically solvable before the detonation.

However, the '3's in Column 9 (Row 6 and 7) would have confirmed that the square you clicked (R7,C8) had to be a mine; there's only 3 unchecked positions surrounding them, two of which you've flagged already, therefore leaving the detonated mine as the final position:

or

• It's probably worth mentioning that marking mines is not required at all. The winning condition is that all cells not containing mines are revealed. Mine flags are there for player's convenience: besides marking spots where player thinks mines are they make cell not react to clicks, preventing accidents
– n0rd
Oct 11, 2018 at 18:36
• @n0rd the flags also mean you can click both mouse buttons simultaneously on a number, and if all the potential mines are flagged, the other squares will be revealed. Oct 11, 2018 at 21:11
• @detly I believe it also clears all un-flagged squares when there is enough flags if you double click. Oct 12, 2018 at 8:56
• @GauravJha You should accept the answer, it is complete. Oct 12, 2018 at 12:20
• [Some comments removed] - Thank you all for your kind words and support of this answer. However I have removed multiple comments now requesting that Gaurav accept the answer. Remember that it is their prerogative to do so and it is not required - there's no need to pester about it. If you want to show support for the action, upvote rus9384's comment instead :-)
– Robotnik
Oct 15, 2018 at 23:43