Whenever you are forced to make a decision, the game will shift the odds in your favor. If you happen to click on a mine, the game will move it — but only if there are absolutely no safe tiles left for you to discover.
After discovering all safe tiles, if there is a pair of tiles each with a 50% chance of being safe, you must click one of them. If no such pairs are available, you can click any tile adjacent to a discovered tile. If neither option is available, it is safe to click any tile.