Minesweeper: earn your first flag with logic
Separate a proven mine from a guess using one complete neighborhood.
Updated 2026-09-21 · GameZoneA number counts eight neighbors
A 1 means exactly one mine among the eight adjacent cells, including diagonals. It does not describe an entire row or only the four cardinal directions.
When a flag is justified
If a revealed 1 has only one unopened neighbor and its other seven neighbors are known safe, the remaining cell must be a mine. Two unknown neighbors would not be enough to choose between them.
When a cell is safe
Once all mines around a number have been logically identified, its remaining unknown neighbors are safe. Flags record your judgment; they do not verify it. One incorrect flag can corrupt later deductions.
Limits of this version
The first opening and its neighbors are protected from mines. Empty regions expand automatically. Random boards are not guaranteed guess-free. Look elsewhere for certain moves before taking a risk. On a phone, toggle Flag mode before tapping a cell.
Try an interactive lesson
Show explanation
It must be a mine. Seven neighbors are safe, so the only unknown cell must supply the one mine. With a second unknown neighbor, that conclusion would not follow.