Minesweeper

Minesweeper is the logic puzzle almost everyone has played: a grid of covered cells, some of them hiding mines, and a number on every cell you open telling you how many mines touch it. From those numbers you work out where the mines are, mark them, and open everything else. This version runs in the browser on desktop and phone with nothing to install, and it keeps the classic rules and the classic number colours, because those are things players already know and changing them only makes the board harder to read.

What is different is the board itself. In the original game the mines are placed at random, and random placement regularly produces a position that logic cannot finish: two covered cells, one mine between them, and no information anywhere on the board that tells you which is which. You are asked to flip a coin, and half the time a clean twenty-minute game ends on the last move for no reason. That is not a difficulty setting, it is the game giving up on you.

Here the board is generated with a solver in the loop. Mines are placed, a logic solver tries to finish the board using only deduction, and if it gets stuck the generator moves one of the mines on the frontier and tries again until the whole board can be reasoned out. Only then does the board reach you. The difference is measurable rather than a slogan: with ordinary random placement, 29 out of 60 boards need a guess. Here that number is zero, and the game says so on the card when you clear a board.

Your first click is always safe and always opens a whole region rather than a single number, so the opening is never a coin flip either. Three sizes carry three different jobs: Easy is 9x9 with 10 mines and teaches the patterns, Medium is 16x16 with 40 and is where chording starts to pay, and Hard is 30x16 with 99, where the frontier gets long enough that you have to pick which end of it to work. On a phone the cells stay at a full touch size rather than shrinking to fit, and a board wider than the screen is dragged to scroll.

There is also one Daily board, the same for everyone, with a streak for coming back and a result you can share. Hint is there for the moment you are convinced the board is stuck: it opens a cell that is provably safe. It is never a gift and never a guess, only the deduction you missed.

Click a cell to open it. The number on an open cell counts the mines touching it, and your job is to work out which of its neighbours they are. Right-click (or long-press on a phone, or the Flag button) marks a cell as a mine, and clicking a number whose flags are all placed sweeps the rest of its neighbours in one go — quick, but wrong flags kill you, so it is a bet rather than a shortcut.

Your first click is always safe and always opens a whole region, never a lone number. The part that is different from every other Minesweeper: the board is built by a solver. It generates mines, tries to finish the board using logic alone, and if it gets stuck it moves a mine and tries again — so the 50/50 coin flip at the end, the thing that ruins the classic game, cannot reach you. Measured: with ordinary random placement, 29 of 60 boards need a guess.

Easy is 9×9 with 10 mines, Medium 16×16 with 40, Hard 30×16 with 99, and on a phone the cells stay at a full touch size and the board drags to scroll instead of shrinking. There is also one Daily board, the same for everybody, with a streak for coming back and a result you can share. Hint opens a cell that is provably safe — never a guess, just the deduction you missed.