The classic rules, unchanged

• Left click opens a cell. The first click is always safe.
• Right click flags a suspected mine. On a phone, press and hold.
• Both buttons (or middle click, or clicking a number) chords: if a number already has that many flags around it, every other neighbour opens at once.
• Clear every cell that is not a mine to win. Flags are optional.

Modes

• Solo — classic play, a fresh random seed each game, board generated around your first click.
• Set Seed — you pick a seed; everyone who plays that seed gets exactly the same layout and the same opening cell, so times compare directly. Share the link and race someone.
• Daily — one board per UTC day for everyone, one ranked attempt per size.
• VS Computer — you and a bot race identical boards side by side. Clear it first, or outlive it.

How runs are verified

Your browser records every click with a timestamp. On a win it sends that log to the server, which regenerates the board from the seed, replays each move, and computes the duration itself. A run that does not end in a verified win never reaches a leaderboard, and the client's own clock is not trusted for anything. Turning on the probability overlay marks a run unranked.

3BV, and why it is on every row

3BV is the smallest number of left clicks that could clear a board. 3BV/s is your clear rate. Raw time favours whichever board happened to be easy; 3BV/s is what lets an expert run and an intermediate run be compared honestly.