How do you flag in Minesweeper?

Right-click any unrevealed cell to place a flag. Right-click again to remove it. On mobile, long-press to flag and tap to reveal. Flags mark cells you have deduced are mines - and critically, they are what makes chording possible: once all mines around a revealed number are flagged, clicking that number instantly reveals all of its remaining neighbours.

How do I flag a spot in Minesweeper

The control depends on your device:

• Desktop: right-click an unrevealed cell to flag it, right-click again to clear the flag.
• Mobile / touch: long-press to flag, single-tap to reveal (you can usually swap these in settings if you prefer flag-first play).
• Mine counter: the number at the top decreases by one for each flag you place, so it reads as "mines you still think are out there" - but only if all your flags are correct.

How do flags work in Minesweeper

A flag is purely a marker for *you*; the cell underneath is a mine only if your deduction was right. Flags do not reveal anything, do not change the board, and are never required to win - you can clear an entire board without placing a single flag. What they do change is your ability to chord: a revealed number will only let you chord once it sees enough adjacent flags to match its value. In other words, a flag is less a "this is a mine" announcement and more a switch that arms a chord.

When to flag (and when not to)

Flagging every mine you spot feels safe but costs time. Competitive players follow a simple rule: flag only when the flag enables a chord. If a mine sits at the edge of the board where no chord will ever use it, marking it is a wasted click that lowers your efficiency score. Many top players play long stretches "no-flag" (NF), clearing cells purely by revealing - NF play on a Beginner board is excellent training for reading numbers without the crutch of markers.

No-flag versus full-flag playstyles

There are two broad approaches, and both are valid:

• Full-flag (FL): mark every mine, then chord everything. Easier to read, more clicks, lower efficiency.
• No-flag (NF): skip flags entirely and reveal only safe cells, finishing the board by elimination. Far fewer clicks and often the fastest style at high skill, but it demands flawless number reading.

Most strong players land in between: they flag only the mines that unlock a chord and reveal the rest directly, capturing most of NF's efficiency without its risk.

The dangers of wrong flags

Never flag speculatively. A wrong flag is worse than no flag, because it can "satisfy" a number incorrectly - and chording on that number then reveals a mine and ends the game instantly. If you are not certain a cell is a mine, leave it alone and look for more information elsewhere on the frontier. This is the single most common way to throw a winnable Expert board.

Flags and your stats

Minesweeper.now counts every click. The efficiency metric compares the clicks you used against the board's minimum (its 3BV), so disciplined flagging directly raises the efficiency number shown on your profile and the rankings. See also: what is chording? and the controls guide.