Minesweeper

About Minesweeper

Minesweeper presents a 9x9 grid of blank tiles, ten of which secretly hide a mine, and asks you to reveal every safe tile without ever clicking on one of the ten that isn't. The only information you get is a number on each safe tile you reveal, telling you exactly how many of its up-to-eight neighboring tiles contain a mine. There's no guessing involved once you understand how to read that number correctly — the entire board, if you play it carefully, can usually be solved through pure logical deduction rather than luck.

A puzzle that became a computing fixture

Minesweeper became widely known through its long-running inclusion as a built-in game on a major desktop operating system starting in the early 1990s, which put it in front of an enormous, largely non-gaming audience over several decades. Its rules never changed much because they didn't need to — the core logic puzzle underneath is genuinely well-designed, striking a rare balance between being simple enough to explain in one sentence and deep enough that skilled players can consistently solve boards that look, to a beginner, almost entirely random.

How to play this version

Left-click any tile to reveal it. Your very first click is always guaranteed to be safe and will never be a mine, no matter where you click, since the mines are placed only after that first click registers. Revealed tiles show either a number, indicating how many of the up-to-eight surrounding tiles contain mines, or nothing at all if none of their neighbors do — in which case the game automatically reveals that entire connected empty region for you, often opening up a large section of the board in one click. Right-click (or long-press on a touchscreen) to place a flag on a tile you're confident hides a mine, which also updates the mine counter at the top so you can track how many unflagged mines you believe remain. Reveal every safe tile without ever clicking a mine to clear the board.

The core logical technique

The fundamental deduction in minesweeper comes from comparing a numbered tile to its unrevealed neighbors. If a tile shows the number 2 and it has exactly two unrevealed neighboring tiles, both of those neighbors must be mines — you can flag them with total confidence, no guessing required. Conversely, if a tile's number already matches the number of neighboring tiles you've already flagged, every other unrevealed neighbor of that tile is guaranteed safe and can be clicked without risk. Nearly every solvable board reduces to repeatedly applying these two rules across different tiles until the whole safe area opens up.

Handling the trickier patterns

Beyond that basic technique, stronger play involves comparing two overlapping numbered tiles against each other rather than looking at each one in isolation. If two adjacent numbered tiles share several unrevealed neighbors, subtracting one tile's constraint from the other's can sometimes reveal a safe tile or a certain mine that neither number alone would have shown you. This pattern — formally related to constraint satisfaction, a concept used well beyond games, in fields like scheduling and resource allocation — is what separates players who occasionally have to guess from players who can solve almost any board through logic alone.

When a guess actually is required

Even with perfect technique, some board configurations genuinely don't provide enough information to determine a tile with certainty, and a guess becomes mathematically necessary. In those situations, the best available strategy is to guess on the tile with the lowest calculated probability of hiding a mine based on the surrounding numbers, rather than picking arbitrarily — not a guarantee, but a meaningfully better bet than a random click elsewhere on the board.

Start a new board

Every new board places its ten mines freshly and independently, with your first click always guaranteed safe. If you like this style of deductive, information-based puzzle, Sliding Puzzle in the same category offers a different but related kind of step-by-step logical planning.