Board games

Much of our countryís computing power is spent playing games. Hereís why.Ö

Shannonís trees

In 1950, Claude Shannon proposed a way to make the computer win at checkers, chess, and other complicated games.

To understand his method, letís try to make the computer win a game of checkers. As in all checker tournaments, one player is called BLACK, and the other is called WHITE (even though his pieces are actually red). BLACK makes the first move. When a player can jump, he must. The game ends when one of the players canít move (either because he has no pieces or because his pieces are blocked).

To simplify the game, weíll play on a 4-by-4 board, instead of the traditional 8-by-8. Each player has two pieces instead of twelve.

This diagram shows 63 possible positions:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Position #1 is the initial position, from which black will move. The three arrows coming from position #1 represent the three legal moves he can choose from. Depending on which move he chooses, the board will wind up in position #2 or #3 or #4. Which move is best?

If he moves to position #2, white will reply by moving to position #5 or #6 or #7.

If he moves to position #3, white will reply by moving to position #8 or #9 or #10.

If he moves to position #4, white will reply by moving to position #11 or #12 or #13.

The diagram shows all possible ways the gameís first five moves could go. Throughout the diagram, w means white man, b means black man, w' means white king, and b' means black king. The diagramís called a tree. (If you turn it upside down, it looks like the kind of tree that grows in the ground.) The arrows are called the treeís branches. The treeís depth is 5.

Which position should black choose: #2, #3, or #4? The wisdom of your answer depends on how deep you make the tree. In this particular game, a depth of 5 is satisfactory; but in 8-by-8 checkers or chess you might have to dig deeper. Theoretically, you should keep digging until you reach the end of the game; but such a tree might be too large to fit in your computerís memory.

For chess, Shannon estimated that a complete tree requires 10120 branches. Einstein estimated that the number of electrons in the universe is only 10110. If Shannon and Einstein are both right, the tree canít fit in the universe!

Having constructed a tree of depth 5, look at the bottom positions (#42 through #63) and evaluate them, to see which positions look favorable for black. You should consider many factors: which player has control of the center of the board? which player can move the most without being jumped? and so on. But to keep matters simple, letís consider just one factor: which player has the most men? Consider a king to be worth 1Ĺ men.

Subtract the number of white men from the number of black men: the result of the evaluation is a number, which is called the positionís value. If itís negative, black is losing; if itís positive, black is winning; if itís zero, the game is heading for a draw.

For example, consider position #42. Since black has one man and white has two, the value is 1 minus 2, which is -1. Thatís why Iíve written "v=-1" underneath that position. The value of each position at depth=5 is computed by that method.

For the positions at depth=4, use a different method. For example, hereís how to find the value of position #29. That position has two possible outcomes: #46 and #47. Which outcome is more likely? Since the move will be made by black, and blackís goal is to make the value large, heíll prefer to move to #46 instead of #47. Since the most likely outcome is #46, whose value is Ĺ, assign position #29 a value of Ĺ also.

Hereís the rule: to compute the value of a position at depth=4, find the maximum value of the positions it points to. (The value of position #29 is the maximum value of positions #46 and #47, which is Ĺ.)

To compute the value of a position at depth=3, find the minimum value of the positions it points to (since itís whiteís turn to move, and white wants to minimize). For example, the value of position #18 is the minimum value of positions #31 and #32, which is 1Ĺ.

Compute the values for depth 2 by maximizing, and the values for depth 1 by minimizing. Finally, you get these results:

The value of position #2 is -1.

The value of position #3 is 0.

The value of position #4 is -1Ĺ.

Since black wants to maximize values, black should move to position #3. If white is also a good player, the game will probably gravitate toward position #53, a draw. If white is a poorer player, black will win.

That method of choosing the best move was proposed by Shannon. Since it makes heavy use of minimums and maximums, itís called the minimax method.

Samuelís checkers

After Shannon, the next person to become famous was Arthur Samuel. He spent a long time (twenty years, from 1947 to 1967) trying to make the computer win checkers. He used Shannonís minimax idea, but made many improvements.

His first spectacular success came in 1962, when his program won a game against Robert Nealey, a former Connecticut checkers champion. After the game, Nealey said "The computer had to make several star moves in order to get the win.Ö In the matter of the end game, I have not had such competition from any human being since 1954, when I lost my last game."

Later, the computer played six more games against Nealey. Nealey won one of them; the other five were draws.

In 1965 the computer played four games against W.F. Hellman, the World Champion. The games were played by mail. Under those conditions, Hellman won all four. But in a hastily played game where Hellman sat across the board from the computer, the result was a draw.

In 1967 the computer was beaten by the Pacific Coast Champion, K.D. Hanson, twice.

In short, the computer wins against most humans and draws against most experts, though it loses to the top champions. To bring the computer to that level of intelligence, Samuel improved Shannonís method in three ways.Ö

1. When choosing among several moves, the computer analyzes the most promising ones more deeply.

2. After computing the value of a position (by examining the positions under it), the computer writes the value on a piece of tape. If the position recurs in another game, the computer looks at the tape instead of repeating the analysis.

3. To compute the value of a position, the computer examines many factors in addition to the number of pieces each player has. The computer combines the factors, to form combination-factors, and then combines the combination-factors to form a single value. The relative importance given to each factor is determined by "experience". Samuel experimented with two forms of experience: he had the computer play against itself, and also had it analyze 250,000 moves that occurred in checker championships.

Chess

While Samuel was programming checkers, other programmers tried to write a similar program for chess. They had a hard time. In 1960 the best chess program that had been written was beaten by a ten-year-old kid who was a novice.

Greenblatt The first decent chess program was written in 1967 by Richard Greenblatt and his friends at MIT. It actually won a game in a chess tournament.

But in most tournaments, it lost. In 1970 and 1971, it lost every game in every tournament it entered.

Slate & Atkins In 1968, Atkins & Gorklen, undergraduates at Northwestern University, wrote a chess program. Inspired by their program, David Slate, a graduate student in physics there, wrote a chess program also. In 1969, Slate & Atkins combined the two programs, to form a better program, Chess 2.0.

During the next several years, they continually improved the program. Their most famous version was called Chess 4.7.

Their program played chess against human experts ó and occasionally won! Their computer scored several triumphs in tournaments designed for humans.

In 1976, their computer won the class B section of the Paul Masson American Chess Championships. Against the humans in that tournament, it scored 5 wins, no losses. By winning that tournament, it achieved a U.S. Chess Federation score of 2210 and became a chess Master.

Then it entered the Minnesota State Championship, to try to become the Minnesota State Champion, but lost (it scored 1 win, 3 losses, 1 tie).

In August 1968, an International Chess Master, David Levy, bet about $5,000 against several computerists. He bet that no computer would win a chess match against him in the next ten years. He won the bet: in August 1978, Chess 4.7 tried one last time to win a match against him, but lost (it scored 1 win, 3 losses, 1 tie).

Slate & Atkins improved Chess 4.7, to form Chess 4.9, which became the world champion of computer chess.

But though it was the world champion of computer chess, it was not necessarily the "best" program. It won because it ran on a super-fast maxicomputer (manufactured by Control Data Corporation). Other chess programs, written for slower computers, were at a disadvantage.

Minicomputer chess Almost as fast as Chess 4.9 was a program called Belle, written at Bell Telephone Laboratories. Belle ran on an unusual minicomputer specially wired to create trees quickly.

Microcomputer chess Each of those programs ó Chess 4.9 and Belle ó required an expensive CPU and lots of RAM. Is it possible to write a decent chess program using only a cheap CPU and very little RAM? Yes! In 1976, a Canadian named Peter Jennings wrote a program called Microchess 1.0; it ran on a $250 microcomputer (the Kim 1), which contained a 6502 CPU, no ROM, and only 1K of RAM! The program played decently, though not spectacularly.

Later, he improved the program, and called the improvement Microchess 1.5. It plays on the Radio Shack model 1 and the Apple. The version on the model 1 consumes 4K of RAM: 2K is for the logic, and the other 2K are just to make the picture of the chess board look pretty! It sold for $20.

In 1978, an amazing chess program was written by a husband-and-wife team: Dan and Kathe Sprachlin. They named the program Sargon, to honor an ancient king. It ran on the Jupiter microcomputer, which contained an 8080 CPU and 16K RAM. It played much better than Microchess. When the Jupiter computer became obsolete, the Sprachlins rewrote the program, to make it run on the Radio Shack model 1 and the Apple. Then they developed an improved version called Sargon 2, and a further improvement called Sargon 3, which runs on all the popular computers. Sargon 3 is published by the Hayden division of Spinnaker.

For many years, Sargon 3 was considered the best microcomputer chess program. But in 1986, Sargon 3 was beaten by a new program called Chessmaster 2000. Like Sargon 3, Chessmaster 2000 contains many features that make it fun for both experts and novices. Itís published by Software Toolworks, distributed by Electronic Arts, costs about $35, and comes in versions for the IBM PC, Apple 2e & 2c, Commodore 64 & Amiga, and Atari 800 XL & ST.

Recently, Sargon 3 has been replaced by Sargon 4, and Chessmaster 2000 has been replaced by Chessmaster 2100 and Chessmaster 3000.

When you play against the computer by using Sargon 4, Chessmaster 2100, or Chessmaster 3000, you can ask the computer for help by pressing a special key. Then the computer will tell you how it would move if it were in your position. You can follow the computerís suggestion or ignore it. Since your goal is to outsmart the computer, you should listen to the computerís advice; but instead of following the advice, try to devise a move thatís even cleverer!

Many companies make hand-held electronic chess games. Some of the games even contain a tiny voice synthesizer, which lets the computer tell you its moves verbally. Some of the games even contain a mechanical arm, so that the computer will pick up the pieces and move them. Some of the games have touch-sensitive boards, so that you can indicate your move by just pushing the square you want to move from and the square you want to move to. For humor, some of the chess games have the computer make wisecracks about your style of playing.

Todayís champion Now the best chess program is Deep Blue, which runs on a specially designed IBM computer. It plays amazingly well and in 1996 almost became the world champion again humans!

Choose a level

When you begin playing a top-notch computer game (such as Chessmaster 3000), you must choose the "level" at which you want the computer to play. If you choose a low level, the computer will move quickly, without much forethought. If you choose a high level, the computer will play more carefully (and make better moves); to do that, the computer "looks ahead", by building a very large tree, which requires lots of time; and so you must wait a long time until the computer moves. If you choose a level thatís very high, the computer will need several hours to compute its move.

Why a computer?

Playing against the computer is more interesting than playing against a human.

When you play against a human friend, you must wait a long time for your friend to move. When you play against Chessmaster 3000 at a low level, the computer moves almost immediately. So you can play several games against the computer (and learn a lot from them) in the same amount of time youíd need to play just one game against a human. So by playing against the computer, you gain experience faster than by playing against a human. Bobby Fischer, who became the world chess champion, now plays only against computers; he refuses to play against humans and hasnít defended his title.

The computer is kinder than a human. If you make a bad move, the computer lets you "take it back" and try again. If you seem to be losing, the computer lets you restart the whole game. The computer ó unlike a human ó has infinite patience and no ego. Playing against the computer is less threatening than playing against a human.

If you have a computer, you donít have to worry about finding an opponent whoís "at your level"; when you play against the computer, just tell the computer at what level you want it to play. The computer will act about as smart as you wish.

Othello

Chess and checkers are both played on a checkerboard. Another game thatís played on a checkerboard is Othello. It uses checkers, but each checker has two sides: one side is white; the flip side is black.

When the game begins, only four checkers are on the board: two of them have their white side showing, and the other two checkers show black.

The game is for two players. One is called the white player, and the other is called the black player.

For example, suppose youíre the white player. On your turn, you put an extra checker onto the board, so that the checker shows white. You must position the checker so that it and a previously placed white checker surround some black checkers. Then you flip all the surrounded black checkers, so that they become white.

Similarly, on his turn, the black player puts a black checker onto the board, so that some of your white checkers are surrounded by black, and he flips all those white checkers, so that they become black.

The game ends when the board is entirely filled with checkers. If most of the checkers are white, the white player wins; otherwise, black wins.

The game is tricky, because the definition of "surrounded checkers" is strange, and because you canít easily figure out whoís winning. At first glance, youíd think that if most of the checkers on the checkerboard are white, white is ahead; but at the end of the game, the situation can change drastically. For example, the black player might place a black checker in such a way that most of the white checkers become black. So you must guard against dangerous positions. During the early parts of the game, the white checkersí positions are more important than their quantity.

The game began centuries ago in England, where it was called Reversi. It resembled the Japanese game called Go. About 1975, it was marketed in the United States as a board game, under the name Othello (which is trademarked by Gabriel Industries). Programmers tried to make the computer imitate the game and win.

After writing Sargon 2 (the award-winning chess program), Dan and Kathe Sprachlin turned their attention to Othello, and wrote an award-winning Othello program called Reversal. It plays Othello better than any other program ever invented. Like Sargon 2, itís been published by Hayden, runs on the Apple, allows several levels of play, costs $35 on disk, and lets you press a "tutoring" button whenever you want the computer to give you advice on how to reply. For added humor, each checker shows a frown or smile. For example, if the white checkers outnumbered the black, the white checkers wear smiles, and the black checkers wear frowns; the smiles and frowns grow bigger, as whiteís lead over black increases. And whenever a checker is added to the board or flipped, the computer plays a musical fanfare.

Unfortunately, Haydenís become part of Spinnaker, which has stopped publishing the program, because most people have forgotten how to play Othello and no longer want to play. Too bad! It was a fun game.

Backgammon

Backgammon is a game played with dice. It requires both luck and skill. For many years, the world champion backgammon player was a human. But recently, he was beaten by a computer, in a thorough match.

The human was a poor loser: he blamed it on "bad luck". He refuses to admit that the computer has more skill than he. Nevertheless, the computer is now the world champion.

Adventure games

Adventure is a game where you hunt for some sort of "treasure".

Original Adventure

The original version of Adventure was written by Will Crowther & Don Woods, on a PDP-10 maxicomputer at Stanford Universityís Artificial Intelligence Lab.

Hereís the gameís plot:

When you run the program, the computer says youíre near a shack at the end of a road. The computer offers to act as your body and understand any two-word command. Then it waits for your command. You can tell it to GO NORTH or GO FORWARD or ó if youíre going along a stream ó you can say FOLLOW STREAM or GO DOWNSTREAM.

The first time you play this game, you feel lost ó the gameís an adventure. As you wander in whatever direction you please, the computer says youíre going through forests, across streams, over hills, etc.

After much aimless wandering, youíll eventually see a stream. If you follow the stream, youíll come to a mysterious iron grate. If you try to BREAK GRATE, the computer says youíre not strong enough. If you try to OPEN GRATE, the computer says you have no keys. Youíll get more and more frustrated, until the computer offers to give you a hint ó but the hint will cost you several points. If you acquiesce, the computer will give you this hint: find the keys!

To find the keys, the typical stupid player tries wandering through the forests and valleys again. But if youíre smart, youíll remember that at the beginning of the adventure you were next to a shack. So you go back to the shack, walk inside, and find keys! So you trek back to iron grate, and use the keys to get in. You think ó aha! ó youíve succeeded!

But actually, youíve just begun! The grate leads you into a cave that contains 130 rooms, which form a big three-dimensional maze. Lying in the maze are 15 buried treasures; but as you walk through the maze, you can easily forget where you are and where youíve come from; you can waste lots of time just walking in circles, without realizing it!

To add to the challenge, the cave contains many dangers, such as trap doors (if you fall in, you break every bone in your body!) and trolls & snakes, which you must ward off by using various devices that you must find in the caveís rooms or even back at the shack. Yes, you might have to trek all the way back to the shack again!

Finally, after dodging all the evil things in the cave, you reach the treasures. You grab them up and start walking away with them. But then you hear footsteps behind you, and pirates steal your treasures! Then you must chase the pirates.

If you manage to keep your treasures and your life and get out of the cave, you havenít necessarily won. The nasty computer keeps score of how well you retrieve the treasures. The maximum possible score is 350. After youíve played this game many times and learned how to duck all your adversaries quickly, youíll find you scored just 349 points, and youíll wonder what you did wrong that cost you 1 point. The answer is: during the adventure, you must borrow magazines from a room in the cave; to get the extra point, you must return them!

The gameís a true adventure, because as you wander through forests and the rooms in the cave, the computer tells what you see, but you donít know whether what you see is important. For example, when you walk into a room, the computer might say the room contains a small cage. Thatís all it says. You must guess whether the cage has any significance and what to do to the cage, if anything. Should you pick it up? Try to break it? Kiss it? Carry it? Try anything you like ó give any command to your computer-body that you wish ó and see what happens.

Hereís a list of the most useful commands:

To reach a different room in the cave, say GO NORTH (or SOUTH, EAST, WEST, UP, or DOWN). You can abbreviate: instead of typing "GO NORTH", just type "N".

Whenever you see a new object, TAKE it. Then you can carry it from room to room and use it later whenever you need it. If you see a new object and want to TAKE it, but your hands are already full, DROP one of the other objects youíre carrying.

To see a list of what youíre carrying, tell the computer to take INVENTORY. To make the computer describe your surroundings again, say LOOK.

To see your score so far, say SCORE.

If you say SAVE, the computer will copy your current position onto the disk, so you can return to that position later. If you ever want to give up, just say QUIT.

Throughout the game, you get beautifully lyrical writing. For example, the computer describes one of the rooms as follows: "You are in a splendid chamber thirty feet high. The walls are frozen rivers of orange stone."

The gameís an adventure about a person exploring a cave. Since youíre the person in the adventure and can type whichever actions you wish, you affect how the adventure progresses and ends. Since itís high-quality story-telling whose outcome is affected by your input, itís called interactive fiction.

Microcomputer versions

Although Adventure was originally written for a PDP-10 maxicomputer, you can get an exact imitation for microcomputers.

The first imitations (published by Microsoft for the Apple 2 and by Creative Computing for CP/M computers) are no longer marketed. Today, the best imitation for microcomputers comes on a disk called the Golden Oldies, published by Software Country and distributed by Electronic Arts. The disk includes four programs: Adventure, Eliza, Pong, and Life. Itís been available for the IBM PC, Mac, Apple 2e & 2c, Commodore 64, Commodore Amiga, and Atari 800 XL. But getting your hands on it is difficult, since itís no longer being actively distributed.

Infocom

After Adventure became popular, several programmers invented a variation called Zork, which lets you input long sentences instead of restricting you to two-word phrases. Like Adventure, Zork consists of hunting for treasures in a cave. In Zork, you reach the cave by entering a houseís basement.

Like Adventure, Zork originally ran on a PDP-10 computer. Infocom has published versions of Zork for microcomputers. Versions for the IBM PC, Mac, Apple 2e & 2c, Apple Macintosh, Commodore Amiga, Atari ST, and Radio Shack Models 3 & 4 cost $39.95. Versions for the Commodore 64, Atari 800 XL, and Radio Shack Color Computer 2 cost just $34.95.

Zork sold so well that Infocom published sequels, called Zork 2 and Zork 3. Then Infocom published other variations, where the caveís been replaced by experiences in outer space or by thrillers involving spies, murders, mysteries, and haunted castles. Infocomís latest big hits are The Hitchhikerís Guide to the Galaxy (based on the award-winning wacky outer-space novel by Doug Adams) and Leather Goddesses of Phobos (which lets you choose among three naughtiness levels, from "prude" to "lewd"; choosing "lewd" makes the computer asks whether youíre at least 18; it also asks whether youíre male or female, and you get a titillating 3-D comic book with a scratch-and-sniff card).

Infocom was an independent company but has been acquired by Activision.

Sierra On-Line

Shortly after Infocom developed the microcomputer version of Zork, Sierra On-Line developed Super Stud Adventure, which was quickly renamed Softporn Adventure. Instead of exploring a cave, you explore a brothel. To enter the brothel, you must find the secret password (hint: go to the bathroom and look at the graffiti!) and find enough money to pay for your pleasures (by taking a taxi to a casino and gambling).

That was the first urban adventure, and also the first sexual adventure. The ad for it showed a photograph of the programmers (Ken & Roberta Williams) nude in a California hot tub. Fortunately, the water in the tub was high enough to cover any problems.

The original adventure, Infocom adventures, and Softporn Adventure display wonderful text but no graphics. Theyíre called text adventures.

The most ambitious graphics adventure ever created was Time Zone, published in 1981 by Sierra On-Line. The Time Zone program is so long that it fills both sides of 6 Apple disks; thatís 12 sides altogether! In fact, the gameís so long that nobodyís ever finished playing it! Hereís how to play:

You use a computerized "time machine", which transports you to 9 times (400 million B.C., 10000 B.C., 50 B.C., 1000 A.D., 1400, 1700, 1982, 2082, and 4082) and 8 locations (North America, South America, Europe, Africa, Asia, Australia, Antarctica, and Outer Space).

Wherever you go, your screen shows a high-resolution color picture of where you are. For example, if you choose "approximately 1400", Christopher Columbus will welcome you aboard his ship. Altogether, the game contains over 1400 pictures! You travel through history, searching for clues that help you win.

Time Zone is historically accurate and doesnít let you cheat. For example, when you find a book of matches in the year 2082, your time machine will let you carry the matches back to 1982 but not to 1700 ó since matches werenít invented until 1800.

Living through history isnít easy. Jonathan Rotenberg, chairman of the Boston Computer Society, played the game and said:

Iíve been killed dozens of times. Iíve been assassinated by Brazilian terrorists, karate-chopped by a Brazilian monk, eaten by a tyrannosaur, crushed in an Andes avalanche, stampeded by a buffalo, overcome by Antarctic frostbite, and harpooned by Mayan fishermen.

And you see it all in color!

Time Zone sold for $99.95. Alas, teenagers didnít buy it, because it took too long to win and was too expensive. Sierra On-Line has stopped selling it.

Recently, Sierra On-Line has made Softporn Adventure even more exciting, by adding graphics. Hereís what the new graphic versions are called.Ö

Leisure Suit Larry in the Land of the Lounge Lizards

Leisure Suit Larry 2: Looking for Love in all the Wrong Places

Leisure Suit Larry 3: Passionate Patti in Pursuit of the Pulsating Pectorals

Creative Computing

Dave Ahl, publisher of Creative Computing Magazine, copied the movie Roller Coaster onto a videodisk, then attached the videodisk player to the computer, to let the computer control which part of the movie you see. He wrote an adventure game that lets the computer illustrate each location and action by a 10-second clip from the movie. When you play the game, your goal is to save your friends before they ride on a roller coaster that crashes. Itís the worldís first video adventure. Your actions determine which part of the movie you see next, which disaster scenes you manage to avoid, and the fate of your friends. Itís the worldís first interactive movie.

Although Dave and his friends all love to play the game, the Actors Guild refuses to let Dave sell the game to strangers. The Guild claims that when Dave shows the scenes in an order different from the original movieís, heís destroying the "artistic integrity" of the actorsí performances.

Ha! Does the Guild really believe that a grade-B horror flick has any artistic integrity at all?

Spinnaker

Spinnaker published the Windham Classics, a series of adventure games based on kidís novels.

You become Dorothy in The Wizard of Oz, Jim Hawkins in Treasure Island, Fritz in Swiss Family Robinson, Alice in Alice in Wonderland, and Green-Sky in Below the Root. The games include graphics. To make those adventure games easy, whenever you get stuck the computer helps you by printing a list of words to try typing.

Spinnaker also published Telarium Software, based on novels that are more adult. You become Perry Mason in The Case of the Mandarin Murder, the crime reporter in Agatha Christieís The Scoop, the researcher in Michael Crichtonís Amazon, and the major characters in Fahrenheit 451, Rendezvous with Rama, Dragonworld, and Nine Princes in Amber.

The Perry Mason one, besides being fun, also trains you to become a lawyer:

It comes with a lawyerís handbook that explains the 6 ways to object to the prosecutorís questions: you can complain that the prosecutorís asking an IRRELEVANT question, relying on HEARSAY, BROWBEATING the witness, LEADING the witness to a suggested answer, getting an OPINION from a person who isnít an expert, or trying to get facts from a person whoís UNQUALIFIED to know them.

To make sure you understand those six ways to object, the handbook includes a multiple-choice test about them. The test is titled "Study Guide for the California Bar Exam".

The game also lets you invent your own questions for the witnesses and give commands to your secretary (Della Street) and detective (Paul Drake).

Availability The Windham Classics and Telarium Software were available for the IBM PC, Apple 2e & 2c, and Commodore 64. But Spinnaker has stopped selling them. Spinnaker is now part of a bigger company, Softkey International, which sells low-cost software thatís more "serious" and doesnít involve fiction.

Broderbund

Broderbund has published a game called Where in the World is Carmen Sandiego? You try to catch and arrest the notorious international thief, Carmen Sandiego, and the other thieves in her organization, called the Villainís International League of Evil (V.I.L.E.), as they flee to 30 cities all over the world.

To help you understand those 30 cities, the game comes with a geography book: the 928-page unabridged edition of The World Almanac and Book of Facts.

As you play the game, you unearth clues about which cities the thieves are fleeing to. But to use the clues, you must look up facts in the almanac. By playing the game, you learn how to use an almanac, and also learn geography. When you figure out which city to travel to, the screen shows a map of the world, shows you traveling to the city, and then shows a snapshot of what the city looks like, so that the game also acts as a travelogue.

Because the game is so educational, itís won awards from Classroom Computer Learning Magazine and the Software Publishers Association.

Strictly speaking, itís not a true adventure game, since it does not let you input your own words and phrases. Instead, you just choose from menus, which make the game easier for youngsters.

Broderbund has created three sequels. Where in the USA is Carmen Sandiego? has you chasing Carmenís gang across all 50 states; the game comes with Fodorís USA travel guide. Where in Europe in Carmen Sandiego? takes you to all 34 countries in Europe and comes with Rand McNallyís Concise Atlas of Europe. Where in Time is Carmen Sandiego? lets you romp through historical time periods.

For the Apple 2 family and IBM PC, the original version costs $39.95, and the sequels cost $44.95 each. For the Commodore 64, you pay $5 less. Those are the list prices; discount dealers charge even less.

Electronic Arts

My favorite text adventure is Amnesia, published by Electronic Arts for the Apple 2e & 2c and IBM PC. Like Softporn Adventure, Amnesia takes place in a city; but Amnesia is far more sophisticated than its predecessor.

Hereís the plot:

When you start playing Amnesia, you wake up in a hotel room in New York City. You discover you have no clothes (youíre stark naked), no money (youíre flat broke), and no recollection of who you are ó because youíre suffering from amnesia. You donít even remember your name.

You look at yourself, and notice youíre a male. Your first problem is to get some clothes and money. But then you learn you have other problems that are even more serious. For example, you get a call from a guy who reminds you that today is your wedding day, and that if you donít hurry up and marry his daughter without further mess-ups, heíll use his pistol. You also discover that the FBI is looking for you, because the state of Texas has reported that youíre a murderer.

After getting some clothes (so you can stop scaring the hotelís maids), there are several ways to get out of your jam. (Iíve tried them all!)

One way is to say "yes" to the pistol-packing papa and marry his daughter, who takes you to Australia, where you live on a sheep ranch for the rest of your life. But then you never learn who you really are! Whenever you ask your wife about your past, she simply says, "You wouldnít want to know." You die of old age, peacefully; but even on your deathbed, you donít learn who you are; and so when you die, you feel sad. In that case, you score lots of points for survival, but zero for detective work and zero for character development.

A different solution is to say "no" to the bride and ó after getting bloodied ó run out of the hotel, onto the streets of New York. Then the fun begins ó because hiding on the programís disks is a complete map of Manhattan (from Battery Park all the way up to 110th Street), including all the streets and landmarks and even all the subway stops! Yes, this gigantic game includes 94 subway stations, 200 landmarks, and 3,545 street corners.

As you walk one block north, then one block east, etc., the computer describes everything you pass, even the most sublime (The Museum of Modern Art) and the most ridiculous (Nedickís hamburger stands). You can ride the subway ó after you get enough money to buy a token. The game even includes all the subway signs, such as "Downtown ó Brooklyn" and "Uptown ó Queens". To catch the E train, you must hop in as soon as it arrives. Otherwise, it departs without you, and the computer says "an F train comes" instead.

As night falls, the computer warns you to find a place to sleep. (You canít go back to your hotel, since youíre in trouble there.) To find a free place to stay, you can try phoning the names in your address book ó once you find a phone booth, and get a quarter to pay for each call. The address book contains 17 listings: J.A., A.A., Chelsea H., drugs, Fį, Sue G., E.H., interlude, kvetch, J.L., R & J, sex, soft, Lila T., T.T.T.T., and Witís End. Each of those listings is an adventure in itself. You must explore each of them thoroughly, to fully discover who you really are.

If your body ever gets weak (from sleeplessness or hunger or being hit by too many muggers), you faint on the sidewalk, wake up in a hospital, and get found there by the FBI, which returns you to the state of Texas, which executes you for murder. But even that deadly ending has a cheery note. For example, you can choose your last meal: would you like steak and potatoes, or turkey? When you finally die, you can wind up in purgatory, which consists mainly of getting mosquito bites, with an opportunity to take a rowboat to heaven, if you can just remember your real name and tell the boatman.

The entire adventure has the structure of a good novel: a gripping introduction (youíre a nude, broke, amnesiac groom in a hotel), a thorough development section (wandering through the streets of New York, searching for your identity and the meaning of life), and a conclusion (a whimsical death scene, or something better).

The text was written by Thomas Disch, the award-winning sci-fi novelist. Itís lyrical. For example, when you escape from the hotel and walk out onto the streets of New York, the computer says: "It feels great to be a single faceless, nameless atom among the million others churning about in the grid of Manhattanís streets. It feels safe."

The game combines all our nightmares about New York into a wild, exciting adventure.

The gameís affected my own life. Now whenever something in my life goes wrong, instead of groaning I just say, "Iím in another wild part of Amnesia!" In Amnesia, as in life, the only way to score top points for living is to experience it all. To live life to the fullest, you must take risks, have the courage to face unknown dangers, and revel in the excitement of the unexpected.

Though Amnesia received lots of praise from reviewers, sales were disappointing. Electronic Arts stopped publishing it. I bet if theyíd rename it "Lost in New York", it would sell well ó at least in New York!

Modern graphics adventures

Modern graphics adventures come on CD-ROMs and include video clips of actual people, with actual sounds, supplemented by wildly beautiful and detailed graphics. Theyíre interactive movies ó partly real, partly animated ó where you control the action!

The world of computer games is changing rapidly! For further details about whatís new & coming, get on the mailing list to receive info about the next edition of The Secret Guide to Computers, by using the coupon on the back page.

Action games

Hey! Letís have some action!

Arcade games

The first popular arcade game was Pong, which made the computer crudely imitate a game of ping-pong. Then came Space Invaders, in which you had to shoot aliens who were dropping bombs on you.

Those games restricted you to moving in just one direction. The first popular arcade game that let you move two-dimensionally was Asteroids. It let you move through the sky while dodging asteroids and enemy space ships.

Those outer-space and sports games appealed mainly to boys. The first arcade game appealing mainly to girls was Pac Man, a non-violent fantasy in which you ran through a maze full of food and tried to gobble as much as possible, before ghosts gobbled you. It appealed especially to dieting girls who dreamed of pigging out without getting caught.

In all those games, the graphics were crude. The first arcade game that used professional graphics was Dragonís Lair, which contained a videodisk full of animated cartoons drawn by artists who had worked at Walt Disney Studios. To dodge obstacles that appear in the cartoons, you move your joystick, which changes the action that the cartoons display.

Each yearís arcade games reflect the latest fads. For example, you can play arcade games about break-dancing and kung-fu.

Game watch

A game watch is a digital wrist watch that plays a video game. If youíre stuck in the middle of a boring business meeting, look at your game watch.

When your colleagues see you looking at your watch, theyíll think youíre an impatient executive tracking the time. Meanwhile, youíre just having fun!

Olympics

In 1980, Tim Smith quit his job at Burroughs and spent the next 9 months programming Olympic Decathlon, which made the Radio Shack Model 1 computer imitate all ten of the decathlonís events.

In his game, one of your fingers represents your left leg, and another finger represents your right leg. To "run", you tap those fingers (left, right, left, right) as quickly as possible on the keyboard. By using those fingers and others, you compete in all ten events: the 100-meter dash, long jump, shot-put, high jump, 400-meter dash, 110-meter hurdles, discus throw, pole vault, javelin throw, and 1500-meter run. You can play solo or against your friends. At parties, you can form teams and cheer each other on.

Later, he wrote versions for the Apple 2 and the IBM PC. Theyíre published by Microsoft.

A competing company, Epyx, has invented a variation that displays better graphics. It comes on a pair of disks, called Summer Games and Summer Games 2. It plays the national anthems of all major countries and includes sixteen games: pole vault, diving, 4x400-meter relay, 100-meter dash, gymnastics, freestyle relay, 100-meter freestyle, skeet shooting, triple jump, rowing, javelin, equestrian, high jump, fencing, cycling, and kayaking. It runs on all popular computers: IBM, Mac, Apple 2, C64, Amiga, and ST.

Sports heroes

A game called One-on-One accurately imitates a basketball shooting match between two stars: Larry Bird and Julius ("Doctor J") Erving. The program imitates each playerís personal strengths and weaknesses. You can take the role of either player and try to avoid getting creamed by the other. Programmed by Eric Hammond with help from Larry and Doctor J, itís published by Electronic Arts.

From Doom to Quake

The most popular computer-action games are Doom and its sequel, called Quake. Theyíre technologically amazing: even on just a 486 computer, they let you run fast through a realistic-looking 3-D environment while you chase and shoot monsters who chase and shoot you!. Even a pacifist like me has to admire the technology! These games use programming tricks that make realistic-looking 3-D graphics come at you much faster than youíd believe possible on a personal computer. A few seconds of playing Doom or Quake will make you say "Wow!"

Though Doom is violent, it has a sense of humor. For example, you can choose 5 levels of difficulty: the beginner level, where you canít get hurt, is called "Iím too young to die". The next step up is called "Hey, not too rough." Then comes "Hurt me plenty", then "Ultra-violence", and finally the expert level, called "Nightmare!" If you try to quit the bloodshed and return to DOS, the program gives you advice such as "I wouldnít leave if I were you. DOS is much worse." It also warns "Sit back with your milk and cookies and let the universe go to Hell ó or act like a man! Slap a few shells into your shotgun and letís kick some demonic butt."

While youíre chasing demons in Doom, the screen shows what your eyes see: your outstretched hand in front of you, holding your gun (or more bizzare weapons, such as chain saws), while a mirror on your wrist shows how bloodied your face got. The action is accompanied by a hard-pumping musical score, keeping your adrenaline up and punctuated by gunfire & ghoulish groans from all the monsters charging at you and being killed, hopefully! You and the monsters charge each other while running through corridors that close in on you faster than any nightmare.

Hereís a formal explanation of Doom (and Quake), written by my research assistant, Len Pallazola, plus his further notesÖ.

Doom revolutionized the computer gaming industry. In Doom (and the many Doom clones that followed it), you see a gun directly in front of you, pointing out at a hallway or room. You wander through a maze of corridors, shooting pretty much anything that moves. In the process, you find bigger and better guns, medical supplies, and other goodies. If you have a modem or your computerís on a network, your friends can join the game and wander through the same maze with you. You can play either cooperatively or in a Deathmatch where you battle your friendsÖ to the death!

Doom was created by a company called Id Software in 1993. Before creating Doom, Id Software wrote Wolfenstein 3-D (nicknamed Wolf 3-D). In it, you must escape Castle Wolfenstein, a Nazi stronghold. Eventually, you may even fight Hitler. If you win, it will mean the end of World War II.

Wolf 3-D wasnít a true 3-D game, but at the time, it was the next best thing. The folks at Id placed 2-dimensional bitmaps on the framework of a wall in such a way that when you moved, the bitmaps would stretch and bend, making it look like your perspective had changed. Even the Nazis were just 2-dimensional bitmaps. You either saw their fronts or backs, but never their sides. Running a true 3-D game requires a powerful computer. Because it wasnít truly 3-D, Wolf 3-D worked fine on a 286.

Id shared its discovery with a few other companies, who made clones of Wolf 3-D. Id also made extra game levels, including a final episode called Spear of Destiny, in which you won by defeating a demon whoíd been helping the Nazis.

After Spear of Destiny, Id created Doom. In Doom, you play a futuristic soldier battling demons and zombies that have taken over your outpost. Doom used the same technology as Wolf 3-D but heightened the realism by letting walls be curved and adding shadowy areas where a torch or gunfire would light up the room.

The most popular feature of Doom was the ability to play with (or against) up to 3 friends by modem or on a network. Doom was one of the first high-speed action games to offer that kind of play, which made it immensely popular.

Once again, Id shared their technology so other companies could make games like Doom. Many extra Doom levels were created, and some were even sold in stores.

Many Doom clones turned up, but the only two that became popular were Interplayís Descent and Lucas Artsí Dark Forces. Later, Id dropped out of sight to work on Quake, the sequel to Doom.

In the meantime, they let a company called Raven Software create Heretic and Hexen, medieval Doom clones sanctioned by Id. In Heretic, you play a wizard wandering through a dungeon battling trolls, gargoyles, and other mythical monsters. In Hereticís sequel, Hexen, you can choose to play a wizard, a warrior, or a priest.

In August 1996, Id released Quake, an almost entirely true 3-D sequel to Doom. In Quake, instead of using rectangular 2-dimensional bitmaps, Id used hundreds of polygons to make up each object or monster ó so the game is extremely realistic and detailed but requires more RAM and a faster CPU (a Pentium or at least a 486DX4-100).

Id added a lot to Quake, which include swimming and fighting underwater, looking up and down, and fighting in reduced (and even zero) gravity. Multiplayer games can now include up to 8 players, and each player can choose which color pants and shirt his character will wear.

For more details about the development of Doom & Quake, see Philip Conradís article "Quake!" in the September 1996 issue of the Boston Computer Societyís PC Report magazine.

How to play Quake Moving around in Quake is easy. Use the mouse to turn and move. Clicking the mouseís left button fires whatever weapon is in your hands. (If youíre out of ammunition for all of your weapons, swing your ax until you find more.) Clicking the mouseís right-hand button moves forward. You can also press these keys:

Key What your character will do

Spacebar jump (or swim)

/ switch to next weapon

a look up

z look down

Esc see the menu

~ chat with other players

When the game begins, a demonstration plays on your screen until you press the Esc key. Select "New Game" or "Multiplayer" to play, or "Load Game" to resume a previously saved game.

Here are some hints:

Be careful when entering a new room: you may walk into a trap.

Donít use the shotgun at long range: you wonít hurt anyone.

Donít use grenades and rockets at point-blank range: youíll hurt yourself.

Here are some Deathmatch hints:

Know your enemy: learn your opponentsí habits and hiding places.

Wear dark uniforms.

Beware of open spaces: stay near walls, and hide in shadows.

Keep moving: if youíre losing a fight, jump into the water to get away.

If you can sneak up on someone, get real close before you start shooting.

After killing an opponent, take his backpack for extra ammo.

Shareware You can download the shareware version of Quake free, from these Internet ftp sites:

ftp://ftp.idsoftware.com/idstuff/quake/

ftp://ftp2.idsoftware.com/idstuff/quake/

Beware: the shareware version is almost 8 megabytes. Downloading it takes about 2 hours with a 28.8-kilobaud modem, 3 hours with a 14.4-kilobaud modem.

You can also get shareware versions of Doom and its clones (except Descent and Dark Forces). Get them from your favorite bulletin-board system or online service.

Bothered? If graphic violence or demonic imagery bothers you, donít buy Quake, Doom, Hexen, and the like. Throughout each, youíll see blood, gore, guts, demons, zombies, monsters, pentagrams, and other occult symbols. If you like a fast action game and youíre not easily offended or "grossed-out", youíll enjoy Quake and its variants.