How to solve mine puzzles without guessing
In a mine puzzle every number counts the mines around its cell, diagonals included. With a few patterns you can read almost any board without taking a risk.
Start with the obvious
A number that equals the number of hidden cells around it means all of them are mines: a 1 with one hidden neighbour, a 2 with two. The other way round, a number whose mines are all marked means its other hidden neighbours are safe.
Compare neighbours
Compare two numbers that share neighbours. If all the hidden cells around one number are also around the other, the first number’s mines are part of the second’s. Two 1s side by side against an edge are the classic case: their shared cells hold that one mine, so the extra cell beside the second 1 is safe.
The 1-2-1 pattern
Along a straight edge, 1-2-1 means the mines sit next to the two 1s and the cell next to the 2 is safe. With 1-2-2-1 the mines sit next to the two 2s.
Mark what you know
Put a marker on every mine you have proven. It does not change the board, but the next numbers become much easier to read, and you will never open a cell you already solved by mistake.
When you seem stuck
Look at the border between open and hidden cells and test one cell in your head: if it were a mine, would a number become impossible? Then it is safe. In Sonar Mines every board is made so that such a cell always exists.
Practise in Sonar Mines
Sonar Mines is built on this logic: your first scan is always safe and every board can be solved without guessing. It has a guided first dive, 30 dives in three depth zones, a daily dive, and hints that explain the logic instead of just opening a cell.