Field Interaction

The player uses the right and left mouse buttons to manipulate the playing field.

A right-click is used to mark a square.

At the start of a game, all the squares are blank.
Right-clicking on a blank square changes it to display a red flag and the number of unused flags is decreased by one.
Right-clicking on a flagged square changes it to display a question mark and the number of unused flags is increased by one.
Finally, right-clicking on a square displaying a question mark causes the square to become blank.
The game is won when all flags are used and all bombs are correctly flagged.
The game is lost if all flags are used and at least one bomb remains unflagged.