Guide
How to Play Minesweeper
Minesweeper asks you to clear every safe square on a hidden grid. Some cells contain mines. Your job is to use the numbers you reveal to identify the dangerous cells and avoid opening them.
Basic controls
Reveal mode opens cells with a click or tap. Flag mode marks suspected mines without opening them. The Reveal and Flag buttons in the game toolbar switch the action used by a normal click or tap.
- Mouse: left-click to use the selected mode; right-click to toggle a flag.
- Touch: select Reveal or Flag, then tap a cell.
- Keyboard: use the arrow keys to move between cells, Enter or Space to reveal, and F to toggle a flag.
Reading numbers and empty areas
A revealed number tells you exactly how many mines touch that cell. All eight surrounding positions count, including diagonals. A blank revealed cell has no adjacent mines, so the game automatically opens the connected blank area and its numbered boundary.
The two essential deductions
- Find safe cells: if a number already touches the same number of flags, every other hidden neighbor is safe, provided those flags are correct.
- Find mines: if a number still needs two mines and has exactly two unflagged hidden neighbors, both hidden neighbors must be mines.
Recognising common patterns
The essential deductions combine into repeatable clue arrangements. The Minesweeper patterns guide explains direct rules, 1-1, 1-2, 1-2-1, 1-2-2-1, holes, and triangle variants using boards generated by the same clue engine as the game. Continue to advanced patterns for reductions, corners, chains, and endgame mine counting.
Flags, counters, and chording
Flags are reminders for likely mine locations. The mine counter is an estimate: total mines minus flags placed. A flagged cell cannot be revealed normally until the flag is removed.
If a revealed numbered cell has the correct number of adjacent flags, activating that number again opens its remaining unflagged neighbors. Incorrect flags can expose a mine, so chord only when you are confident.
When a mine ends the game, ClassicWorks shows the mine that was triggered and crosses out flags placed on safe cells. Other mine locations remain covered so the board still reflects what was known when the mistake occurred.
Random and numbered games
Random games
In a random game, mines are placed after your first reveal. The first revealed cell is always safe and, where the mine density allows it, its surrounding cells are protected too. The displayed seed identifies the random sequence, but choosing a different opening cell can produce a different board layout.
Numbered games
A numbered game chooses a deterministic safe opening and reveals it when the game starts. The game number, difficulty, and generator version then produce the same opening and mine layout for every player. Use the Share button to copy a direct challenge link.
Numbered-game completion times are submitted to the community record service. They are browser-reported community bests rather than independently verified competition records.
Difficulty levels
Beginner uses a 9 by 9 board with 10 mines. Intermediate uses 16 by 16 with 40 mines. Expert uses 30 columns by 16 rows with 99 mines. Every difficulty uses the same responsive tile size, calculated from the space required by the Expert grid.
A reliable solving routine
- Scan the edge of every open area for numbers with only a few covered neighbors.
- Flag only mines that are logically certain. An uncertain flag can make a later chord dangerous.
- After adding flags, rescan nearby numbers for newly forced safe cells.
- Open certain safe cells before making another guess. One reveal often creates several new deductions.
- Use Undo for an accidental input, not as evidence that an uncertain move was logically safe.
Some randomly generated positions can require a guess. ClassicWorks does not currently promise that every board can be completed through deduction alone, so exhaust the available logic before choosing between equally plausible cells.
Common questions
Do I have to flag every mine?
No. You win by revealing every safe cell. Flags are optional tools for tracking mines and enabling chords.
Why can the mine counter become negative?
The counter subtracts every placed flag from the total mine count. It can fall below zero if more flags are placed than there are mines.
When does the timer start?
The timer starts with the first board action, whether that action reveals a cell or places a flag. It stops only after every safe cell has been revealed and every mine has been correctly flagged.
Are random seeds the same as numbered games?
No. A random seed identifies the random sequence, while a numbered game also fixes the opening cell so every player receives the same complete challenge.