COLUMN: 'Beyond Tetris' - Minesweeper

["Beyond Tetris" is a column from Tony "Tablesaw" Delgado about puzzle games that transcend mere abstract action and instead plunge deep into the heart of problem-solving. This installment looks at one of the most commonly available PC puzzle games: Minesweeper.]

Though Microsoft claims that Vista will usher in a new age of PC gaming, the first thing it will do is usher in the old age of PC gaming. Despite hardcore clamoring for high-end graphics-card-melting titles, the only games that the majority of people care about are the ones they've been playing for years, the ones that are ready with no complications whenever the urge to do something other than work arises, the ones that are packed in with Windows—Hearts, Klondike, Mah Jongg Solitaire, etc. Of the common games that come with Vista, two are true puzzle games; FreeCell will have to wait until another time, because today I'm talking about Minesweeper.

Mining the Past

Minesweeper has its origins in the earliest mainframe games of the '60s and '70s. Wikipedia cites the earliest ancestor of Minesweeper as Jerimac Ratliff's Cube. But although Cube features "landmines," it's hard to consider this a predecessor of Minesweeper. In Cube, the mines are placed randomly and the only way to discover where they ends the game. You walk over a landmine and you die; you can't avoid the landmines or know where they are before you take a chance.

However, there are a number of very early "hide and seek" games about locating hidden spots on a grid. For example, in Bob Albrecht's Hurkle, you have to find a creature hiding on a ten-by-ten grid. After each guess, you're told in what general direction the Hurkle lies. Dana Noftle's Depth Charge is the same, but in three dimensions. Bud Valenti's Mugwump has multiple hidden targets, and after each guess, you get the approximate distance to each of them. Unlike Cube, these games match the general pattern of Minesweeper more closely: make a random guess to start, then start using the information provided by that first guess to uncover the hidden items. Of course, unlike Minesweeper (or Cube), the was no danger of "explosion," the only constraint was finding the secret locations in a limited number of guesses.

The closest ancestor to Minesweeper is probably Gregory Yob's Hunt the Wumpus. Although it used an unorthodox grid (the original game used the vertices of a dodecahedron, and a later version used Möbius strips and other unlikely patterns), the Wumpus evolved from its predecessors in many other ways.

Like the previous hide-and-seek games, the goal was to figure out where randomly placed locations were on the grid. But there was no time limit for exploration. Instead, like in Cube, the locations in Wumpus were hazardous: entering those rooms would put you at risk of losing. And most importantly, the only way to figure out where these hazards were was to be one space away. The key to solving Wumpus was getting as close as possible, backing off, and shooting your "crooked arrow" from a distance after definitively locating your prey.

When games like Quicksilva's Mined Out; Virgin Interactive's Yomp; and Conway, Hong and Smith's Reletless Logic appeared in the '80s, they looked like Cube on the surface: move from one point to another avoiding randomly placed mines. But in terms of solving, the games played more like Wumpus: move along safe areas, then put all the information to use locating the hidden dangers. Tom Anderson's Mines later added a feature that let you mark suspected mines with flags. And the stage was finally set for the Minesweeper to (ahem) explode onto the scene.

Dropping the Bombshell

The Minesweeper that we all know and love was created by Robert Donner and Curt Johnson while they were working at Microsoft. It was first released as part of the Microsoft Entertainment Pack for Windows in 1990, but in 1992, it replaced Reversi as a pack-in game for Windows 3.1. Minesweeper became a Microsoft staple, and from 3.1 to 95 to XP and beyond, millions upon milions of people across the world turned to Minesweeper when the random chance of Klondike Solitaire became overwhelming.

Unlike the previous minefield games, Minesweeper has no avatar. You can check any location on the board without having to find a path there. And because there's no avatar, the goal is no longer safe passage; instead; you must clear every non-mined square of the grid before you have succeeded. There is a timer and a best-score high-score list. (The high scores are easily manipulable, though; Vista's Minesweeper looks to be more resistant to such techniques). Using a two-button mouse to quickly reveal and flag squares, the game moves much faster than its predecessors. And in addition, there was a pleasant smiley face at the top of the game.

Like many simple logic games, Minesweeper relies on recognizing common patterns. After getting used to the game, you start to see some of these patterns on your ownm but the more complicated patterns will only be noticed if you're truly dedicated to working out the logic. Many people aren't willing, because many of the randomly generated boards of Minesweeper involve guessing anyway. It's fairly common to discover that, after clearing almost all of the board, there are two cells, each with a fifty-fifty chance of hiding a mine. Of course, the hardcore sweepers still use logic to analyze the patterns and turn the odds in their favor.

With Minesweeper's high-score table as a starting point, Minesweeper became competitive. There are several websites around the world for players to submit rankings. These competitive sweepers eventually refined their scoring systems using something called Bechtel's Board Benchmark Value (or 3BV). The 3BV is the minimum number of clicks it takes to clear a given board (barring some special tricks), and serves as the de facto difficulty rating for the many possible Minesweeper boards. In the image to the left, the each white or green dot is one necessary click, making the 3BV of the board 16.

Minesweeper attracted academic attention too. In 1999, Patti Frazer Lock and Allan A. Struthers began using Minesweeper to introduce students to formal logic. And in 2000, Richard Kaye proved that Minesweeper is NP-Complete, linking it to one of the $1 million prizes of mathematics. This connection to deep mathematics along with the game's wirdespread popularity led to a critical cameo in an episode of the TV show Numb3rs.

Smarter Bombs

Minesweeper had a knack for knock-offs. I know that when I was in high school in the early '90s, I coded my own Minesweeper clone in QBasic because my 286 couldn't handle Windows. Sadly, my code is now several hard drives gone, but there are plenty of other folks who had the same yearning, coding Minesweeper games for Mac, Linux, Unix, OS/2, and undoubtedly many other systems. Some of them, like the straigthforwardly named Minesweeper Clone, were designed to facilitate the competition and analysis I've already talked about. Clone has detailed record-keeping features that are used for personal enlightment or for competition on the Planet Minesweeper website.

But even the clones seem to be overpowered by the many, many variants. Because Minesweeper's boards are randomly generated, not handmande like Sokoban's, they've multiplied faster than most puzzles. There's hexagonal and triangular Minesweeper.

There are two kinds of 3-D Minewseeper, one version is on the flat surface of a three-dimensional solid; the other takes place within a gridded three-dimensional space. Minesweeper has been translated into a pen-and-paper puzzle where carefully chosen spaces are pre-revealed. One Minesweeper "variation" is actually just a randomly generated game of Picross. There's even a Minesweeper with large cartoon breasts. G.Rev, a Japanese developer took hexagonal Minesweeper and turned it into an J-Pop–based arcade game, Doki Doki Idol Star Seeker, which was later ported to the Dreamcast. (Detailed English information about this game can be found in issue #1 of The Gamer's Quarter.)

In doing this research, my personal favorite has been Crossmines by John Valentine. In this variant (shown above), each space can be a variety of different shapes, and the board can have holes in it. These two twists alone make for a pretty interesting game. But most bizarrely, there is an option for "linked cells" which connects different spaces across the board and makes them act as one. I've tried in previous drafts to explain how this works strategically, but I haven't been able to. Honestly, I'm not sure I entirely understand it myself. It's extremely bizarre, and if you're interested, you should try the game yourself.

Just as it was back in 1992, I don't have the power to load the latest Windows onto my computer. Thankfully, I now have more than enough Minesweeper options at my fingertips. At the moment, the best list of clones and variants is the Wikipedia page on Minesweeper. As daunting as the list is, I supsect they're all easier to install than Vista.

[Tony Delgado is a member of the National Puzzlers' League, and a solver and creater of puzzles of all sorts. He also works as the copy chief of The Gamer's Quarter, which just published its eighth issue.]