Flag Technique — Play Free Online

Flag Technique takes the classic mine-clearing puzzle and rebuilds it for the modern browser, with a 16x16 grid, 40 hidden mines and absolutely nothing standing between you and your first click.

Flag only when a mine is certain; speculative flags create false confidence later. Gameplay is simple to state and hard to master: reveal a square, read the number it shows, and use that count of adjacent mines to prove where the danger is and where it is not.

Use the left mouse button to open squares and the right button to mark suspected mines. Touch users get a dedicated mode button instead of an awkward long press, which keeps flagging fast under time pressure.

Nobody enjoys losing on move one, so the board is not built until you click. The generator then places all 40 mines away from your opening square and the ring around it, guaranteeing a usable cascade to start from. The build is intentionally light. Server-rendered HTML paints instantly, the game logic is a few kilobytes of client-side state, and every sound is generated at runtime by an audio oscillator instead of streamed from a server.

Reset as often as you like — every restart randomises a completely new layout, so no two boards are ever quite the same. Whether you are here for a quick distraction or a serious attempt at a personal best, the board is ready the moment the page finishes loading, and it costs nothing to try again.