The History of Minesweeper

For about twenty years, Minesweeper came free with almost every Windows PC. That's why so many people know it. The idea behind it is older, though, and the game has had a surprisingly interesting life since.

Before Windows

Hidden-hazard games on a grid go back to the early days of home computers. Mined-Out, released for the ZX Spectrum in 1983, had you walk across a minefield while the game told you how many mines were next to you. In 1985, Relentless Logic by Conway, Hong and Smith used the same kind of clue on a grid, with the player working out a safe route. The core idea of Minesweeper, reasoning from counts of nearby dangers, was already there.

The Windows game

The version most people know was written at Microsoft by Robert Donner and Curt Johnson. It first appeared in 1990 in the Microsoft Entertainment Pack, a set of small games sold for Windows 3.0. In 1992 it moved into Windows itself with Windows 3.1, alongside Solitaire.

Both games had a practical side. Solitaire got people used to dragging with a mouse, and Minesweeper made them comfortable with left and right clicks. For many office workers it was their first real practice with a mouse.

The three levels

The Windows game set the board sizes that nearly every version still uses today.

Level	Board	Mines
Beginner	9 × 9	10
Intermediate	16 × 16	40
Expert	30 × 16	99

Our Master board, 30 × 24 with 200 mines, is a later addition for players who want more than Expert.

Mines or flowers

Not everyone was comfortable with a game about landmines. Some translated versions swapped the theme: the Italian version became Prato fiorito, a flower meadow. When Microsoft redesigned the game for Windows Vista, it added a flower field you could choose in place of the mines.

After Windows

With Windows 8 in 2012, Minesweeper stopped being part of the operating system and became a separate free app. By then it had spread everywhere: phones, calculators, websites and countless clones. The rules barely changed, because they never needed to.

A problem for mathematicians

In 2000, mathematician Richard Kaye showed that a general version of Minesweeper is NP-complete. In plain terms, deciding whether a Minesweeper position is consistent belongs to the same family of hard problems as many famous puzzles in computer science. Nobody expects a fast method that works for every possible board, however large.

Speed and records

Minesweeper also became a competitive game. Players race to clear the three classic boards, mostly Expert, and communities keep ranked lists of verified times. To compare games fairly, players use a measure called 3BV, the smallest number of clicks needed to clear a board without flags. Dividing 3BV by your time gives a speed that means more than the time alone, since some boards are easier than others.

No guessing

The biggest change in recent years is the no guess board. Classic Minesweeper can leave you with a pure coin flip. Many modern versions, including ours, can instead deal only boards that a logic solver can finish, so skill decides every game. You can try it in No guess mode.

Questions people ask