What a Suvi board promises
Before you see a board, Suvi's solver plays it from the starred square. If logic alone can't clear it, the layout is thrown away. The solver's tools, cheapest first, are the ones you need:
- Opening blank areas (the game does this for you).
- Reading one number at a time.
- Comparing two numbers that share hidden squares.
- Now and then, working through every way the mines could sit along a stretch of edge, with the mine counter as a final check.
The starred square has no mines round it, so your first tap always opens an area. Easy is 9×9 with 10 mines, medium 12×12 with 24, and hard 16×16 with 44.
Read every number after its flags
Subtract the flags already touching a number and you get what it still needs. Call that the reduced number. Then two rules do most of the work:
- If the reduced number equals the hidden squares it touches, they are all mines.
- If the reduced number is zero, every other hidden square it touches is safe.
A 3 with two flags beside it behaves exactly like a 1. Every pattern below works on reduced numbers, so train your eye to see them.
Subtraction: the 1-1 and the 1-2
When two numbers sit side by side on the edge of the open area, compare the hidden squares each one touches.
- 1-1: one 1 touches hidden squares A and B; its neighbour touches A, B and C. The first 1's mine is in A or B, and that also satisfies the second 1, so C is safe.
- 1-2: a 2 touches A, B and C, and the 1 beside it touches only A and B. Exactly one mine is in A or B, so the 2's other mine must be C.
The general rule: whatever the bigger number needs beyond the smaller one must sit in the squares only the bigger one touches. This is the move that unsticks most boards.
The 1-2-1 and 1-2-2-1 along a wall
Both turn up where a straight row of numbers faces a straight row of hidden squares.
| mine | safe | mine |
| 1 | 2 | 1 |
|---|
The squares facing the 1s are mines and the one facing the 2 is safe. If the middle square were the mine, both 1s would be used up and the 2 couldn't get its second mine.
| safe | mine | mine | safe |
| 1 | 2 | 2 | 1 |
|---|
Here the squares facing the two 2s are mines and the ends are safe. In both patterns the hidden square just past each end is safe too, because each 1 already has its mine. They often hide inside longer walls, so read every straight edge as a line of reduced numbers.
Corners and edges
A square on the edge of the board has five neighbours and a corner square only three, so numbers there fill up fast. Work the board's edges early.
The open area has corners too. Where it wraps round a corner of hidden squares, the number tucked into that elbow touches just one hidden square, diagonally. If it still needs a mine, that square is it. A number on an outside corner is the opposite: it can touch five hidden squares and rarely tells you much alone, so leave it until its neighbours are settled.
Chording: clear round a number in one tap
Suvi supports chording. When a number has exactly the right count of flags round it, tap the number itself and all its other hidden neighbours open at once. On a phone it saves a lot of taps, and it's the best reason to flag at all: the board is finished when every safe square is open, flagged or not.
The catch is that a chord trusts your flags. If one is on a safe square, the chord opens the real mine beside it. So only flag what you've proved, then chord freely. Flag with the Flag mode button, a press and hold, or a right-click on a computer.
The endgame: let the counter decide
The counter shows mines left: the total minus your flags. It rarely matters early, but at the end it can be the whole answer. Say three hidden squares are left, A, B and C. One number still needs one mine from A or B, another needs one from B or C, and nothing else touches them. Either B is a mine on its own, or A and C both are. If the counter says 1, it's B; if it says 2, it's A and C. Suvi's solver falls back on this count when nothing else works, so some boards need it in the last few squares. Keep your flags honest so the counter is too.
If you only remember three things
- Subtract flags from every number before you read it.
- Compare neighbouring numbers: what one needs beyond the other lies in the squares only it touches.
- Stuck means you've missed a move, not that you need to guess. Walk every straight edge looking for 1-2-1 and 1-2-2-1.
Put it into practice on today's medium board, or warm up on easy first.
Questions
- What should I do when I can't see a move?
- Go round the edge of the open area one number at a time: reduce it by its flags, then compare it with each neighbour. If the edges give nothing, count the mines left against the hidden squares that remain. On a Suvi board a logical move always exists.
- Do I have to flag every mine?
- No. The board is cleared when every safe square is open. Flags help you keep track, keep the mine counter accurate and let you chord.
- Why did tapping a number open a mine?
- That tap was a chord, and one of the flags round that number was on a safe square, so the real mine opened. Check your flags before chording.
Play it now
Mines is free on Suvi, on your phone or computer, no download. Also: Easy Mines · Medium Mines · Hard Mines.