How to play
- Pick a difficulty (or set rows, columns and mines for a custom board) and click any cell to start – a zero opens a whole area.
- Read the numbers: a 1 next to exactly one hidden cell means that cell is a mine. Right-click, long-press or switch on Flag mode to flag it.
- When all mines around a number are flagged, click the number to reveal its remaining neighbours at once.
- Keyboard: arrow keys move the cursor, Space or Enter reveal (or chord on a number), F flags, N starts a new game.
- Clear every safe cell to win. On a standard board a new best time is highlighted and kept for next time.
Example
Three hidden cells lie in a row below a revealed 1 · 2 · 1. The 2 needs two mines among its three hidden neighbours; the left 1 allows only one mine in its two hidden neighbours, and so does the right 1. The only arrangement that satisfies all three is a mine under each 1 and a safe cell under the 2 – the classic 1-2-1 pattern. Flag the two outer cells, then click the 2 to chord open the middle one. The same logic gives the 1-2-2-1 pattern: the two mines sit under the 2s.
Rules and scoring
The board follows the Microsoft Minesweeper rules: a reveal on a mine ends the game and shows every mine, with flags on safe cells marked as wrong; revealing a zero floods outward until it reaches numbers; flagged cells are never revealed, not even by a chord. Chording only triggers when the number of flags around the number equals the number itself – if one of those flags is wrong, you lose. The game is won the moment the number of revealed cells equals cells − mines; the remaining mines are flagged for you.
Score is time only: whole seconds from the first reveal to the win, capped at 999 on the classic counter. Best times are stored per standard difficulty under calcpark:minesweeper:best:v1in localStorage; custom boards are playable but not ranked. Mine placement uses the browser’s random generator on your device; nothing is sent to a server.
Sources: Wikipedia – Minesweeper (video game), Minesweeper wiki – Strategy and patterns.
Questions
- Is every board solvable without guessing?
- No. Mines are placed at random, so some boards – especially on Expert – end in a 50/50 guess, typically along an edge or in a corner. The safe first click and the 3×3 opening reduce but do not eliminate guessing.
- How do I flag on a phone?
- Either hold a cell for about a third of a second, or turn on Flag mode so every tap places or removes a flag. Tap a revealed number to chord as usual.
- Why does the mine counter show a negative number?
- The counter is mines minus flags. If you place more flags than there are mines it goes negative, which is a hint that at least one flag is wrong.
- What are the classic record times?
- Top players finish Beginner in about 1 second, Intermediate under 10 and Expert in roughly 30 seconds. Anything under 100 seconds on Expert is an excellent amateur time.