Minesweeper terms, defined

Minesweeper has its own small vocabulary — chord, flood fill, frontier, 50/50, and more. Knowing the words makes the solving guides far easier to follow. If you are brand new, start with the beginner's guide; once the basics click, the solving techniques page puts these ideas to work.

Cell / Square

A single square in the grid. Every cell is either covered or revealed; a revealed cell shows a number, a blank, or a mine. A cleared board has every safe cell revealed.

Mine

A hidden hazard buried under a covered square. Reveal a mine and the game ends. The total number of mines is fixed and shown in the counter above the board; your job is to reveal everything that is not a mine.

Number

The digit shown on a revealed square, from 1 to 8. It counts exactly how many of the eight surrounding squares are mines. A 3 means three of its neighbors are mines — the diagonals count too.

Flag

A marker you place on a covered square you believe is a mine, by right-clicking (or long-pressing on mobile). Flags prevent accidental clicks and make nearby numbers easier to read. They are not required to win, but they enable chording.

Reveal / Open

To uncover a covered square with a left-click. If the square is safe it shows a number or a blank; if it is a mine, the game is over. Revealing is the only action that actually wins the game.

Blank / Zero

A revealed square with no mines among its eight neighbors. Because it is surrounded entirely by safe cells, the game automatically reveals all of them — which is what triggers a flood fill.

Flood fill / Cascade

The chain reaction when you reveal a blank square: the game opens every adjacent blank, and their neighbors, and so on, instantly clearing a large region bordered by numbers. A good opening click often sets off a big cascade.

Chord

Clicking a revealed number that already has the correct count of flags around it, which reveals all its remaining covered neighbors at once. A huge time-saver — but if a flag is wrong, chording detonates a real mine. See the techniques guide.

Safe cell

A covered square you have proven cannot be a mine, so it can be revealed with no risk. Finding safe cells by logic — rather than guessing — is the whole skill of the game.

Frontier / Edge

The boundary between revealed numbers and the covered squares they touch. Nearly all deductions happen here, because only frontier numbers carry information about which covered squares are mines.

Counting

The core deduction: compare a number against the covered squares it still touches. If the number equals that count, all are mines; if its mines are already flagged, the rest are safe.

Subset elimination

Comparing two overlapping numbers to learn about the cells one sees that the other does not. The technique behind the named patterns — the extra mine a larger number demands must sit in its extra cells.

1-2-1 pattern

A common shape: three numbers reading 1 2 1 along a covered edge. The mines sit under the 1s and the cell under the 2 is safe. Its relative, 1 2 2 1, puts the mines under the 2s.

50/50

A situation where two covered squares are equally likely to hold the last mine and no clue can decide between them. The one moment minesweeper can force a true guess — though most apparent 50/50s dissolve on a careful recount.

Mine counter

The display showing how many mines remain unflagged. It is global information the local numbers cannot give you, and it often resolves end-game positions that look unreadable from the edge alone.

Difficulty (easy / medium / expert)

The standard board presets. Easy is a small grid with few mines, expert is a large grid densely packed with them. Difficulty is driven mainly by mine density, not just grid size.

Streak

The count of consecutive days you have solved the daily board. It is kept on your device, so coming back each day to clear the daily keeps the streak alive.