The full-size challenge
Expert is 30 squares wide and 16 tall with 99 mines, one in every five squares. Games are longer and the patterns run into each other, so it rewards patience more than speed.
On a laptop the board fits the window; use the zoom buttons or Ctrl and the scroll wheel to make the squares bigger. On a phone held upright the board stands on end so the squares can be larger, and you can pinch to zoom and drag to move around.
Expert boards are checked by the same solver as the smaller ones, so even here there is never a forced guess at the end.
How to play
Each number tells you how many mines touch that square, counting the eight squares around it. Use the numbers to work out where the mines are, flag them, and open every other square to clear the board.
With a mouse
- Left-click opens a square. Your first click is always safe and opens an area.
- Right-click places or removes a flag.
- When a number already has all its flags around it, click it (or click with the middle button, or both buttons together) to open the rest of its neighbours at once.
On a tablet or phone
- Tap opens a square. Press and hold to place a flag.
- The Reveal and Flag switch under the board changes what a tap does, if you prefer flagging with a tap.
- Tap a number whose flags are all placed to open around it.
- On big boards, pinch to zoom and drag to move around, or use the zoom buttons.
With a keyboard
Arrow keys move between squares, Space opens, F flags, and C or Enter opens around a number. H asks for a hint. Press ? on the board for the full list.
Hints
Hint lights up one square that is certainly safe (or certainly a mine) and the numbers that prove it, with one plain sentence explaining why. Each hint adds 10 seconds to your time, and your statistics count how many you used.