Computer logic game, popularized by its distribution with the Microsoft Windows operating system. Played on a grid of hidden cells, each of which may or may not contain a mine (unknown to the player). Clicking on an empty cell reveals the number of immediately adjacent mines, and clicking on a mine loses the game. The object is to determine the locations of all mines without ever clicking on a mine cell.
This puzzle has been studied from a complexity point of view. In particular, the standard version (on a general-size board) is known to be NP-complete. See Richard Kaye's page in this category, his paper "Minesweeper is NP-complete," Mathematical Intelligencer, 22(2):9-15, 2000, and Ian Stewart's "Million-Dollar Minesweeper," Scientific American, 283(4):94-95, Oct. 2000.