A Voice from the Dungeon Hat

A Voice from the Dungeon.

Drawing on his experience running Essex University's MUD, Richard Bartle speculates on the possibilities of multi-user games.

One of the most intriguing prospects envisaged by games players is a multi-player version of Adventure. You would not only be pitted against fiends provided by the game designer but could also be thwarted by another player, who might well appear out of the blue and mug you for all your treasure!

Although proper multi-player Adventure-type games are probably a fair way off for micros, programmers have already taken advantage of the resources available on the larger, time-sharing mainframes to make the first experiments along these lines. Multi-User Dungeon is the first and, so far as I know, the only large-scale up-and-running multi-player Adventure. It is written for the DEC System 10 mainframe-which happens to be the same make of machine as the one on which the original Adventure took its first few steps.

MUD originated at Essex University, where its kernel was written in 1979 by a then undergraduate, Roy Trubshaw. Even in its infant form, the game easily overtook Adventure in popularity among the students. When Trubshaw left in 1980 I took over control of the program and expanded it to its present-day form.

MUD runs on the university's DEC System 10, which has a KL-I0 processor running under Tops-10 monitor version 7. Communication between players is by shared data using a writable, sharable segment of physical memory. It runs in around 64K 36-bit words, much of which is the shared data, and uses another 40K in random-access disc files for non-changing information such as text. For speed it is written in BCPL.

When he wrote MUD, Trubshaw aimed to produce a multi-player game with a modifiable database. The modifiable database was required to allow changes to be made quickly and easily, without having to recompile the MUD program itself- which is similar to the state of not changing your Basic interpreter in order to modify your Basic program. It was considered undesirable that the program might otherwise have hardwired within itself a line to, say, check if the bear were following you, as is the case in Adventure. What if the database designer wanted a world without a bear, but with some other animal instead, or a world with a bear which was not quite so friendly?

MUD's database is written in a language called Multi-User Dungeon Definition Language, MUDDL. It has undergone many enhancements from which it has emerged with a quirk or two, but is definitely a success. It only takes about two minutes to add a new room, the connections to other rooms, the associated objects and the things you can do to them. It is all done with a normal editor, and the resulting program is compiled by DBase, the database loader, which sets up all the internal representations so that MUD itself can come along, eat, and interpret.

The program structure allows great flexibility and permits MUDs to be chained together so that leaving a room from a certain direction might put you imperceptibly into an adjacent room which is actually in another MUD, running with an entirely different world. The only penalties are not being able to talk across such MUDs or take things over with you. Such facilities would require shared data, a luxury unavailable between programs. Of course, within the same world, communication is very heavy.

A MUD can be likened to an interpreter trundling over a program, which happens in this case to be a description of an environment. Players run one of the interpreters and play in its world, but that MUD may run another version loaded with different data in order to give the impression that the world it represents is larger than what it can actually hold.

Modifiable databases permit applications for programs in many non-game worlds. The two classic non-Adventure examples are Taxi drivers "On the knowledge" and biology students travelling through the human body: "You are heading up the superior vena cava. On your right you can see...". Other applications are not too difficult to imagine - say finding your way in advance across the London Underground, or following current along electrical circuits.

Home computers are unlikely to use this facility, at least for the next few years. Storing instructions implicitly as a program (that is, procedurally) is more compact than storing the same information explicitly as data and then interpreting it. So until larger memories become commonplace, it will always be more economic to hardwire a program. Why program in MUDDL when Basic is halfway to being as good and you probably have a basic interpreter already? Besides, what software manufacturer is going to release games interpreters which run a language so simple a child can write Adventures is this means they will not sell so many of their own games as a result?

Another reason we will not be seeing home computers with multi-player Adventures in the future is that their implementation is likely to involve one micro running a series of slaves, rather than a network or ring of independent machines. This will make switching to another world - another program - a bad idea, whichever representation for it you choose. If one person wants to leave for another world then everyone else has to go as well. Different sections of a world are awkward on a small machine anyway. It would be a definite damper on any game to have something like "You are now leaving this module: please insert disc MUD001 and press Return" printed out at you in mid-Adventure.

All those crafty techniques do not really impress the players. What attracts them is something whih sounds exciting, like the multi-player aspect. The first thing most new players do on meeting another player is attempt to kill them. More advanced players will maybe follow you, wait until you are half dead killing the wolf or something, then steal your pickings and run away. It comes of watching too much Tom and Jerry on TV, so the sociologists tell us.

Having sated their blood lust, the next thing people do is try to explore. In this respect MUD is much the same as a normal Adventure, although the descriptions tend to be better because of the extra space available to keep them on our industrial-size disc packs. Some aspects do differ, however, for example, you may have to ask for help in order to lift up a heavy portcullis.

At this stage of the game players tend to chat to other players and seek help directions, advice, or ask if they have seen Fenwyn and has he still got the sword? They may join together in small groups, lest they are set upon by one of the nasties which roam the land, in which case they can gang up on it and do it a bit of no good. The party will also be useful to carry the treasures they find, until they figure out that some of the pack animals, such as the ox, will help them take more weight with them, too. Only one member of the group need carry a light source. Eventually, having amassed some goodies, they will want points for their modest haul.

A problem here is how to give players points for treasure without letting other players pick up the treasure and do the same thing. Normally, in single-player games, points are scored for dropping things somewhere, but in a multi-player game you have the problem that someone else might come along and try to pick it up. It is intensely annoying to be told that the objects lying there in front of you are regrettably unavailable. If you make it disappear when dropped in the place, you need a feasible explanation for its disappearance - and not just "magic". You cannot just have it disappear every time someone picks it up instead, or make them eat it, because often the treasure has other uses: the axe kills people and chops down trees and doors, as well as being treasure.

The solution is to make the treasure disappear when dropped in certain selected places. It is made ptain th@t you will not be able to pick things up from there by their very nature. You can score points for your own treasure; no one else need see it, and you only have yourself to blame if you did not realise it was going to disappear. In MUD you have to cart treasure to a swamp so it is pretty obvious that if you were to drop it you would not get it back.

Having doused your brand so that you do not blow yourself up setting light to the marsh gases you walk in, say "Drop treasure" or whatever, and score the points. The treasure disappears, then you realise in horror that you wanted to keep the statuette of the lion because it leads you through the graveyard maze. The swamp, incidentally, doubles as an ingenious maze itself, which cannot be mapped by the conventional method of dropping objects, as they just sink. The only non-sinking items are players, so you need co-operation to find the route through to the dry bit in the middle where the crown is hidden.

There are other ways to get points apart from dropping things in the swamp, but they involve destruction of the object in question, as in drinking the potion or killing the dryad. The only exception is kicking the beggar, which earns you a single point every time you are prepared to type out the necessary long command. Killing him, incidentally, would get you about 50 points, assuming you won. Some of the tasks are surprisingly complex: for example, finding the rope to fix to the gunpowder to put in the cannon, finding the metal ball to load the cannon and lighting the rope to discharge the cannon a a sturdy door.

Safe places to hide treasure are in short supply too. Only a certain number of objects may be carried, depending on your dexterity and only up to a certain weight, depending on your strength. Although bags and pack animals will to some extent alleviate this problem, they often prevent you going where you want. The ox will not jump off the cliff with you even if you have got the umbrella. and even if it is open. There is no guarantee that leaving an object in one place will mean that it will still be there when you return. It is a case of finders keepers, and your beautiful gold-bound book may be being used to feed the goat by then. The solution is to employ a guard or put it somewhere such as a locked room where no one else can reach it - but then your keys may be stolen from you.

For those who like the idea of posterity, messages and advice for future players can be left behind. The main debating forum is the captain's logbook on a wrecked ship out to sea. Comments ranging from "Pascal rules OK" to "Dragons kill 99 percent of known mortals" have been left for the benefit and edifiction of future generations of adventurers.

Most exploring is done by logging the game in a file and looking at it later. It is a handy device, but not of much practical use on any micro version, primarily because the game can be printed out on the printer as you play. Also useless unless you are in a timesharing environment is the Bug feature - well it bugs me - which allows players to complain about any aspect of the program which they think is wrong. I have just completed a map of where all the terminals in Essex University are, so that in the future it may append to a message "You have been killed by Nic" the note "who is sitting two rows behind you to your left...".

One feature which enhances MUDs - though it is a complete waste of time in single-user dungeons - is being able to sleep to recuperate your lost stamina, say after a hard slog at a zombie. You get back a point every 10 seconds or so, but of course if some vindictive type chances upon you while you slumber, you cannot expect to be playing for much longer.

Originally MUD had a Debug mode to check out new sections of the database. It is tedious to have to get the coracle to brave the shark to reach the island in order to find the acorn to give to the squirrels when you eventually get back. Now called Wizard mode, Debug mode has evolved into a sort of on-going end-game which continues to fascinate even master players who have been in 4,000 games or so. It is Wizard mode which makes MUD something more than just a tarted-up single-user game.

Flying around and glowing in the dark while in Debug mode are quite useful features, and after a while other perks were inserted with only a little extra work. Being able to look in rooms without going there, kill people with a single blow, pick up objects from any room without having to fly there first, find the location of objects without having to search for them - all these were a cinch to put in for debugging, and made life comfortable for the program maintainers.

The change came with the Snoop command. It allows someone in Debug mode to see what is on the screen of some other player, without that other player knowing. Suddenly, a command became available to the elite which was not actually any use for debugging. After I first implemented the facility, I spent the next three hours just sitting watching the other players stumbling around asking each other stupid questions and eventually managing to cook up an intelligent solution to all the traps I had laid on for them. It was a revelation.

So was born Wizard mode. It came at a useful time, too: as with most Adventure-type games, once you have all the points it is a case of "So what now?". In the pre-programmed, non-random games such as the original Adventure and the superb Zork there is an end-game which you may enter once you have earned most or all of the points. The end-games soften the blow because they are specially constructed climaxes, and a new section comes as a welcome surprise if you know the rest of the place like the back of your hand. But then, that's it. You have finished. You go out and buy a new disc with a new game, and start off from scratch.

In MUD, the concept of a level was borrowed from the real-world game Dungeons and Dragons, from which Adventure took the original fantasy role-playing idea. D&D still beats computer versions hands-down because people are better dungeon masters than computers - and you cannot threaten a computer when things do not go your way. A player in MUD starts off as a novice, and when anyone meets them in the flesh or types Who, to see who is playing, they are told that, say, Polly is here. After 300 points, Polly goes up a level and becomes Polly the Warrior. Strength, dexterity and stamina go up by 10 too. After 600 points it would be Polly the Heroine and after 1,2000 Polly the Champion. As the points double successively Polly becomes the Superheroine, followed by Enchantress, Sorceress, Necromancess, Legend and finally, at 76,800 points, Witch. At this stage, strength, etc. are at the maximum of 100, although that does not really matter since wizards can change any of their attributes when they like.

As you reach higher levels of experience you accrue abilities and magical talents. For example, at Enchanter level the deadly magic wand - a sort of medieval laser - can be used to dot off most of the denizens of the land without so much as a by your leave. The ability to cast certain spells appears if you are in possession of the relevant magical item. Such magic lets you see what other players are doing, summon people to where you are so that you can attack them, find out where items are, and so on. In short, they are the least dangerous of the Wizard mode commands. On reaching that final level, the Wizard mode password is revealed, and for you the game has entered a new dimension.

All the time you have been playing you were being pestered by wizards who kept appearing with crashes of thunder, and disappearing in puffs of smoke. If you were stuck they have miraculously known, and you have suddenly found yourself in possession of just the item you needed to get you out but which you dropped in the fiery pit by accident. You have been whisked from the centre of the maze to somewhere you actually recognised, and reluctantly put back if it turned out you were not lost in the first place. You have attacked the pompous, know-it-all, god-like so-and-so's and been ground into the floor first hit; insulted them and found things typed on your screen you did not type. But now you have made it to wizard yourself you can teach them...

The first thing you notice is that the prompt has changed from a boring old * to an impressive magic wand ---*. Next you observe that you are told the names of all the objects you come across, so you can see what is lurking hidden in a room even if mortals cannot. You can switch the rain on and trap someone underground when it floods the river. Hmm, useful.

Then all of a sudden you get a message: "Cynthia has started to play MUD having played 0 times before". Aha! "Get flower from garden. Go start. Give flower to Cynthia. Hiya, Cinth!" From maniacal, paranoid, kill-it-if-it-moves legend you have transformed into kindly, benevolent, tolerant, omnipotent wizard.

You will soon pick up some of the other nifty Wizard mode commands, such as an attach/detach feature which lets you play two or more characters at once and swap between them. One moment you are a wizard, the next a simple novice asking dozy questions to egg players on so that you can give them a bit of what for when they set about you with an axe. Oh, that feeling of veiled power!

Adventure-like games can be improved drastically by better descriptions, graphics of some quality and by the increased experience of the games designers themselves. Having the odd multi-user game on resource-sharing micros will enliven many an evening, but the real fun only comes when the players do not necessarily know each other and are of varying degrees of experience.

The database must be large enough not to bore players by making them get most of their points in several nigh-identical sessions. In MUD, if you get all the treasure you can make wizard in four games. Having several other players in at the same time makes this harder, but you get more points for each individual item and for winning fights.

What I would like to see - and it's a long, long way off - is some local or national network with good graphics, sound effects and a well designed set of worlds of varying degrees of difficulty. In this true meritocracy, you will forever be encountering new situations, new difficulties, new solutions, and above all new people. Everyone starts off on an equal footing in this artificial world.

It is doubtful whether multi-userness is going to be more than just a novelty among the better-off home-computer enthusiasts for a good while yet. Setting up a network over telephone or cable TV lines would have to be big enough business to attract more than just the hobbyist, too. So perhaps we will eventuatly see a decline in the popularity of the micro Adventure and an increase in a more continuously running campaign. Still, who wants to play in a game full of primary schoolkids going around locking you in small rooms just for laughs? Mind you, they wouldn't if there was a wizard watching... We'll have to wait and see.

Copyright © Richard A. Bartle (richard@mud.co.uk)
21st January 1999: avftd.htm