This is the logic at the heart of the classic minefield game, as a puzzle you can think about: part of the field is already open. Each open number counts the mines among its eight neighbours; open blank squares have none around them.
Flag every mine. The total number of mines is shown, and every puzzle is checked so that it can be solved by deduction alone — never a coin toss.
Start with numbers that have exactly as many closed neighbours as their value: all of those are mines.
Use the open numbers to flag every mine in the field — every puzzle can be solved by logic, without guessing.
The full guide, with a worked example and common mistakes: How to play Mine Finder.
No — every puzzle is generated and checked so that each mine can be found by logic.
It has no mines among its eight neighbours.
Yes — every puzzle here has exactly one solution.
Yes — open the Mine Finder Solver, type the open numbers and the mine total, and press Solve.