Click (or tap) a cell to reveal it. Numbers show how many mines touch that cell (including diagonals). Use right‑click or long‑press to flag suspected mines; flagged cells shouldn’t be opened later. Your objective is to clear every safe cell without detonating a mine. On the first move, it’s fine to open a random corner to create space. Big empty regions are safe—expand from them, then use the numbers to reason about the remaining fringe.
A classic pattern: if a ‘1’ touches exactly one unopened cell, that cell must be a mine; conversely, if the required number of mines around a number is already flagged, the rest of the unopened neighbors are safe. Chain these deductions across the board and you’ll often clear large patches without guessing.