The History of Minesweeper

Before Windows: Mined-Out and Relentless Logic

The core idea, numbers that count hidden mines nearby, did not start with Microsoft. Mined-Out, a 1983 game for the ZX Spectrum published by Quicksilva, had you cross a minefield while a number told you how many mines sat next to your position.

Relentless Logic, a game for personal computers from the mid-1980s, is another title usually listed among the ancestors. It used a board of covered squares with numbered clues, much closer to the grid we know today.

Accounts of who influenced whom do not agree. Curt Johnson has said he borrowed the design from an earlier game, but not from Mined-Out, so treat any single "origin" claim with caution. What is clear is that the ingredients were already circulating: hidden mines, neighbor counts and deduction instead of chance.

Who invented Minesweeper, and when?

The Windows version people mean when they search for Microsoft Minesweeper is credited to Robert Donner and Curt Johnson. Sources describe their roles differently: one has Johnson designing the game and Donner programming the Windows version, another has Johnson creating it first and Donner porting it. Development is usually dated to around 1989.

Here is the timeline in short:

• 1983: Mined-Out appears on the ZX Spectrum.
• Around 1989: Donner and Johnson's Minesweeper is developed.
• 1990: it ships in Microsoft's Entertainment Pack for Windows.
• 1992: Windows 3.1 includes it as a built-in game.
• Windows 7: the last Windows release that includes the classic game.

The year most people remember is 1992, when Windows 3.1 put Minesweeper on a very large number of desktops. A search for "minesweeper 1989" is usually about the date it was written, not the date most players first saw it.

So there is no single inventor of the genre. Earlier games supplied the idea; Donner and Johnson turned it into the grid, the mouse controls and the difficulty levels that people still compare against.

Why Windows came with a mine puzzle

A free game inside an operating system sounds like a gift, but it was also practical. Early Windows users were learning to use a mouse, and games are a painless way to practice. Solitaire is commonly said to have taught dragging and dropping; Minesweeper is often credited with teaching precise clicking and the difference between the left and right buttons.

It also fit the office. A round takes a few minutes, needs no installation and can be dropped the moment someone walks past. That combination made it a fixture of lunch breaks long before smartphones.

The three classic boards became a shared language. In current Windows versions, Beginner is 9 by 9 with 10 mines, Intermediate is 16 by 16 with 40 mines, and Expert is 30 by 16 with 99 mines. Early versions used a slightly smaller Beginner board, but almost every later clone offers these three presets.

What changed with Windows 8

Windows 7 was the last version to include the classic game as a built-in program. Starting with Windows 8, Minesweeper was no longer part of the default install.

Microsoft instead offered a modern Minesweeper app through its store. It added daily challenges and other extras, and it is free with ads, with a paid option to remove them. Microsoft has changed how it distributes its casual games over the years, so check the store listing for current details.

For many players the practical effect was that the game stopped being something you simply found in the Start menu. People who wanted the old look turned to browser versions and third-party clones, which is one reason so many web versions exist.

Competitive play and world records

Minesweeper is also a timed sport. Players race to clear the three standard boards as fast as possible, and community-run sites such as Authoritative Minesweeper keep rankings of the fastest times. Many serious players use chording, clicking a satisfied number to open its neighbors at once, because it saves clicks. You can read how it works on the flags and chording page.

The times are startling. Beginner records are around one second or less, Intermediate records are single-digit seconds, and Expert records are under half a minute to about half a minute, depending on which list and rules you follow. There is no single governing body, so figures differ between sites, and records are broken from time to time. Check a current ranking before quoting any number.

Because some boards are simply easier than others, rankings also track 3BV, short for Bechtel's Board Benchmark Value. It is the fewest clicks needed to open every safe cell without using flags or chording. Dividing 3BV by the time gives 3BV per second. For example, a board with a 3BV of 100 cleared in 40 seconds scores 2.5, while a 3BV of 30 cleared in 20 seconds scores only 1.5, so the first player is the faster solver even though the second finished sooner.

Why mathematicians care: the NP-completeness result

In 2000, the mathematician Richard Kaye published a paper showing that a question about Minesweeper is NP-complete. The question is whether a given arrangement of numbers can be explained by some placement of mines at all, known as the consistency problem.

NP-complete problems are a famous class: no fast general method for solving them is known, and finding one would settle the P versus NP question, one of the Clay Mathematics Institute's Millennium Prize problems. That link produced some excited headlines about a million-dollar prize.

Do not read too much into it. The result concerns arbitrarily large boards and a very specific question, not whether a 9 by 9 board is hard for you. Ordinary play still comes down to the logic on the numbers page and the shapes on the patterns page.

Where the game went next

Minesweeper spread into mobile apps, web versions and puzzle collections. One notable direction is boards generated so that they can be solved by logic alone; Simon Tatham's Portable Puzzle Collection includes a Mines game with this option. For why classic boards sometimes force a guess, see avoiding guesses.

Variants also changed the shape of the board: hexagonal grids, three-dimensional cubes, and boards with no fixed edge. Removing the edge changes how the game feels, because there is always another region to move to when one gets stuck.

Minesweeper Worlds Online is one such variant. Its map extends infinitely in every direction and is divided into areas of 8 by 8 cells. Open a mine and only that area locks, and the rest of your world stays as it is.

It also has a Shared World, one map for all players during a season, where other players' moves appear live. Play there is cooperative and asynchronous, not head to head. You can read more in what Minesweeper Worlds Online is and how the Shared World works.

To compare the modern take with the classic, the game runs free in your browser from the play page, with no download required.