Minesweeper

Your first click cannot kill you

Most versions of this game let you lose on the opening move, which is a stupid way to begin. Here the mines are not placed until you have already clicked. The square you pick is guaranteed empty and so are all eight around it, so the flood fill takes the whole pocket with it. On Beginner one click usually clears twenty or thirty squares.

That guarantee is why the clock can exist. With the dead opening move gone, only reading speed stands between you and a solved board.

Counting is the easy part, counting under a clock is not

A number tells you how many mines touch that square. That is the entire ruleset, and most mistakes come from reading a number as a claim about squares it does not reach. Work from the outside in: a corner square has three neighbours and a wall square has five, so edges tell you more per square than the middle of a big open pocket, where every deduction is a guess wearing a hat.

Two habits separate a two minute Expert from a ten minute one. Flag only what you have proved, because a wrong flag poisons every number beside it. And clear in one direction rather than hopping about, since six open fronts is six sets of constraints in your head at once.

What a one against a wall is really telling you

These shapes turn slow deduction into recognition. A 1 against a wall with exactly one hidden neighbour left is that neighbour, every time. Two 1s with a 2 between them against the same wall is the classic 1-2-1: both outer hidden squares are mines, and the square under the 2 is safe. A 1-2-2-1 against a wall is safe at the outer ends and mined at the inner pair.

When nothing can be proved, guess where being wrong costs least. On Expert you will meet roughly one honest coin flip per board. Take it early, while the clock still has room, and take it where a lucky square opens a wide area.

Chording is the move that saves the run

Once the flags touching a number match the number, click the number itself, or put the cursor on it and press C. That is a chord, and it opens every remaining hidden square around it in one move. It is only safe because a chord runs on flags you have already proved: chord a number whose flags you placed by feel and you will open a mine and end the run. The cursor outlines a revealed number's hidden neighbours, so you can see what a chord will touch.

The score is squares plus seconds

Every safe square you reveal is worth 4 points on Beginner, 5 on Intermediate and 6 on Expert, paid the moment it opens, which is why the score in the corner moves during the run. Clear the board and you also collect 4, 6 or 8 points for every second left on the clock. That second half is where a good score comes from: a Beginner board finished with 250 seconds to spare pays a thousand points for the time alone.

Hit a mine and you keep the squares you cleared and nothing else. Let the clock reach zero and the payout is the same. The three timers are 5, 10 and 15 minutes. Your fastest win at each difficulty is kept separately, and the best score in the corner is the best across all three.

Losing on a coin flip, and other questions

Is the first click really always safe?

Yes. The mines are placed after your first reveal, and the placement skips the square you clicked and its eight neighbours, so your opening move is always a zero and always floods its own empty region. You cannot lose before you have made a decision, and the score is already non-zero from that first click.

What does chording actually do?

Clicking or pressing space on a number that is already revealed counts the flags touching it. If that count matches the number, every other hidden neighbour opens at once. If it does not, nothing happens, so an early chord is harmless. It is the fastest way to clear a board and the fastest way to lose one, because a chord runs on your flags.

Why can a coin flip still end a run?

The first-click guarantee only covers the opening square. A board can genuinely finish with two hidden squares, one mine, and no number that separates them. Expert averages about one of these per board. Take it early rather than late, and pick whichever square opens more of the board.

Do flags score anything?

No. Flags are a notebook. Placing one changes the mine counter and stops a stray click from opening that square, and that is the whole of it. Points come from revealed safe squares and from the seconds still on the clock when the board is cleared.

What happens when the clock runs out?

The run ends there, the board is revealed, and you keep the points for the squares you had cleared, exactly as if you had hit a mine. The clock starts on your first reveal rather than when the panel closes, so reading the board before you begin costs nothing.

Why I put a clock on a game that never had one

Minesweeper has always been a game you could leave open for an hour, which is not what this site is for. A countdown gives a run a beginning and a definite end, and it makes the two real skills here worth something: reading the numbers quickly, and not wasting clicks. Nobody should lose a Beginner board to the timer.