It's probably best to say first what this article is not about. I recieve quite a lot of feedback from people who have played adventures I have written, and the following is a typical message:

"Thanks for your hints in regard to Fyleet. I've made considerable progress since dealing with the wizard and am now up to around 300 points. I've still had no luck getting the phoenix out of its present state. I did manage to get Bacchus to do something useful for me; however, this raises the question as to whether the barrel is useful or can be ignored. Also, is the symbol of Hurgenpor (in the tunnel after riding the Hippogriff) useful at all? I'm currently trying to deal with the Dwarf and the A-Z exit. Still unsolved are how to pass without a trace and float like a feather. Am I correct in assuming that it really isn't necessary to wish at all? It seems that by wishing you're forced to lose one treasure."

Well, I don't propose to answer any of those questions here, more to give some ideas of how one constructs adventure puzzles. There is a classic joke that seems appropriate here:

Q. How many adventure players does it take to change a lightbulb?
A. One to type BREAK BULB, another to try EAT BULB in the wrong room, another to try WAVE BULB...

The moral being that whatever you do and however obvious you think a puzzle is, there will always be some contingency you don't allow for, and someone who will try something you didn't think anyone would try.

Adventures come in a variety of styles, with different aims and plots (sometimes rather thin ones). A few typical 'player goals' are:

• Collect loot (Classic Adventure, Acheton, Murdac, Philosopher's Quest);
• Win back your kingdom (Kingdom Of Hamil);
• Impress someone enough that they will help you fight some adversary (Fyleet, Crobe);
• Show virtue enough to win the Holy Grail (Sangraal, Quest For The Holy Grail!);
• Escape from prison (Xandos);
• Regain your sanity and then fulfil some mission (XENO);
• Kill a mighty wizard (Parc);
• Kill a giant (Giantkiller!);
• Get off a planet alive (Countdown To Doom);
• Get out of the world you're in (Avon);

Let's have an example of a typical adventure game (Crobe).

                        SEA / BEACH
                  O----------------------O----------------O
                  |                       CLIFFS           \
                  |
               O--O--O flour             O----------------O lemming
               | / \ |                   | mystic
        zombie O     O TOWN              | pole
               | \ / |                   | flame
               O--O--O accordion         |
                  |                      |
        fish O----O----------------------O----O princess, throne
        RIVER            ROAD        |
                                     |
                                     O witch

                         THE START OF AN ADVENTURE

Well, I don't intend to explain how to do this but, for illustration, let us look at some of the 'above ground' features.

Over to the west we have the ruined town of Croke and its sea-front with the tide in. Objects which may or may not be of use include a wandering zombie, a bag of flour and an accordion. Also a dead fish washed up on a river bank. Over to the east, outside the town, there is more to see: a witch, who demands that you discuss some interesting topic with her (though initially nothing seems to interest her); a princess on a golden throne; a mystic sitting on a pole near a fire; and a statue of "The Unknown Lemming", appropriately placed at the cliff edge.

Experiment suggests that eating the fish is not a good idea, as it needs cooking. However, when you cook the fish on the sacred fire, the mystic grabs it and runs off, complaining that he hasn't eaten for weeks and your action in cooking fish nearby is more than his flesh and blood can stand. So this leaves you with a pole, by the cliff edge.

Kissing the princess is obvious enough: she turns into a frog, allowing you to sit down on the throne. In best Canute style, this causes the waves to recede and the beach to appear. The frog itself has another use later, but at this stage it just makes strange croaks of "WEEBLE", "BARGLE" etc at you.

Proceeding along the beach you find a cave entrance, but since there is a cyclops standing in it, it is rash to go further. Instead you go back and push the pole over the cliff (so that he comes out to investigate) and finally push the lemming over (crushing him). In fact the items you haven't yet used do come in useful later, although you have to explore a bit further to see how they fit into the game. That's probably a fairly hard opening for an adventure.

Let me give some examples of what I consider to be bad puzzles - where the player feels dissatisfied, even when he's solved them (I'm not claiming that I can always do better!). They all come from games which otherwise are good in many respects.

Waving the rod (a magic wand) in Classic Adventure: first of all you are supposed to wave it in places where it is not at all obvious that you need to do anything at all (e.g. at a fissure, where a crystal bridge appears); secondly there are places where you need to wave it twice before anything happens. This seems a bit unfair. The player ends up trying to wave the rod everywhere he goes.

The magazines in Classic Adventure. You score a point for leaving them somewhere. It is not at all clear why!

In Zork, there is a curtain of fire. Saying GO NORTH (or whatever direction it is) doesn't let you pass through. WALK THROUGH CURTAIN is required. No one knows why, and most people have to be told the precise wording.

Again in Zork, there is a puzzle founded on Baseball. Not much point if you don't know the game!

In Hezarin, there is a place where you see the illuminated sign "G - 1 - 2 - 3". The answer is ENTER LIFT. All right, there is a puzzle here - to recognise that it's a lift. But I would prefer CALL LIFT as the solution and would have wanted to allow PRESS BUTTON or whatever as well (assuming that there is a lift button).

In L: A Mathematical Adventure, there is an elliptical billiard table where the ball starts at one focus and you find that, whatever angle you hit it in, it goes into a pocket at the other focus. All very interesting, but totally useless: there isn't a puzzle there at all, it's merely rather irritating local colour - irritating because the player looks for a problem that isn't there!

How much magic do you put into an adventure? Well, there are perfectly good adventures (eg. Xenophobia, which is set in London) in which no magic is involved. At the other extreme you have adventures with magic words chalked up on every wall and the poor player going all the way round the game trying to find out where exactly the word "BZZZT" does something, only to discover that you have to be in the Great Hall and holding both the parrot and the teapot, but having already eaten the melon and thrown the pig at the duchess. I exaggerate, but you see what I'm objecting to: purposeless magic. Magical artefacts that suggest what they might be useful for (eg. mushrooms that when eaten make you strong, causing you to wonder where strength might be useful) are much better than objects with irrelevant magical side-effects.

I'd like to say something here about the conventions of adventure games, and how they can be made less hackneyed. Firstly, Mazes. Many adventures have mazes of some sort in them. They vary from the elementary (drop objects in order to make the rooms look more different from each other) to more subtle variants.

In Zork, for example, dropping objects is partially thwarted by a thief, who wanders round and picks them up again ("My, someone's left a fine sword here!"). In the Kingdom Of Hamil maze, life is made harder for the player by the fact that every time he leaves a room. the ceiling collapses, and so he can't visit any room more than once (and needs to visit all the rooms in the maze since they all contain something). In Acheton there are the Ice Mazes, where the ice is always about to melt: a thermometer is used to identify the safe way through.

Sangraal has a rotating maze, where the directions keep changing. Fyleet has a greatly simplified version of the Fifteen Puzzle, where you have to manoeuvre objects about that cannot be put two in the same room. Murdac has a haunted house, where a poltergeist is throwing objects at the player, who has to deduce where the ghost is and avoid it. Philosopher's Quest has the notorious Garden of Eden, where the serpent very persuasively offers the player all sorts of rewards if he will eat the apple on the tree. Finally the snake says "Do I have to spell it out for you? You're in EDEN!" The directions E-D-E-N may be found helpful here.

Another convention is the Rusty Rod (sometimes with a star on the end). In various games that becomes a magic wand, a morning star (the weapon), a crowbar, an electrical conductor...

How much combat do you put in an adventure game? Classic Adventure has the dwarves (and the player has a nonzero probability of being killed whatever he does). In Acheton there is a little green-eyed idol (cf. the famous poem about a one-eyed yellow idol to the north of Khatmandu), which when robbed of its eye comes back for vengeance: and if the player is unlucky he will get it! MUD of course contains large elements of combat, as does the original Fantasy game. Mystic Wood and Sorcerer's Cave have been computerised, and make amusing "Hack-and-Slash" games.

Combat systems can be rudimentary or very sophisticated indeed. You can have a simple system where the player has a fixed probability of winning a battle, right up to a full simulation of the system in some Role Playing Game like Dungeons And Dragons or Runequest.

So where does one get ideas for puzzles? The answer is, almost anywhere, as I'll indicate.

One useful source is literature. One can pinch, I mean adapt, all manner of classical themes. The Sword in the Stone has been used in numerous games (in Classic Adventure you need the strength to pull it out, in Quondam it breaks and needs repairing, in Crobe it's held in an anvil by electromagnetism and you need to break the circuit). The Ancient Mariner turns up in Philosopher's Quest, and you end up with an albatross round your neck that needs removing. The Hunting of the Snark provides a puzzle in Kingdom Of Hamil, the Phoenix legend to Fyleet.

I once saw an opera (a Russian one, I think) where someone filled a golden bowl with water and saw a vision. The idea was used in Murdac. Moses and the Ten Commandments (or, more precisely, the eleventh) have a role to play in Sangraal, as do Edgar Allan Poe's Raven (Nevermore) and Shelley's Ozymandias!

Given an item in a game, one often devises puzzles which exploit its various possible uses. A witch's broom can be used for sweeping the floor to expose a trapdoor. A duster can be a bandage, a cloth, etc. In Fyleet there is a prayer mat which, when used appropriately, causes a mighty wind to arise. This can blow things out of trees, disperse fog, and so on.

Thematic puzzles are enjoyable, and you get several at once that way. Sangraal has two such. First there is a 'Seven Deadly Sins' area, where the object is to commit each of the sins in turn - being slothful, being gluttonous, and so on (I had trouble implementing Lust in a tasteful way!). It also has a Noah's Ark puzzle, where you have to find animals to take to Noah: sloths in trees that need waking, wolves that are too fierce to handle, tied up emus that it seems impossible to free, and others!

Some puzzles depend crucially on timing. Acheton has several such: a giant who stomps around in a regular path (and will crush you if you are in the wrong area at the wrong time); the mummy Yelka Oekim who must equally be evaded (the solutions are different!); a notorious snake maze which you can explore while the snakes are asleep, but which you must activate later, risking attack from the snakes, in order to liberate the treasure. Another example is Crobe's ship wrecking: you have to let some pirates take over a ship, then show a false light to guide them onto the rocks!

Some puzzles come naturally and the adventure writer also has to struggle to find a solution. For example, in the barn in Fyleet, an animated white sheet descends on you and smothers you: it was my wife's idea that the player should wear a spiky Teutonic helmet to protect himself. Elsewhere I needed a one-way exit to avoid the player returning the way he'd been. The barn naturally suggested a bale of hay, down onto which the player could jump.

Finally, there are plenty of conventional puzzles which can be put into adventure settings. A few examples will be found in the final part of this article.

A couple of examples of conventional puzzles follow:

                       ENTER
                       ENTER
                       ENTER
                      ======
                      HEROES

The above is an alphametic. The numbers solving it can give a combination used elsewhere.

UIF QBTTXPSE JT IPSTF. A cryptogram (suitably arranged in a crypt in Kingdom Of Hamil).

Then there are steals from Dudeney and other famous puzzlists: "Lost - one wolf, one goat, one cabbage". The old puzzle about transporting wolf, goat and cabbage without leaving the wolf alove with the goat, or the goat with the cabbage.

Logic puzzles:

   NW exit: If this is the safe exit, then N is False.
   N exit: If this is the safe exit, then NE is False.
   NE exit: If this is the safe exit, then NW is True.

Puzzles based on Binary and Ternary systems ("Hippogriff rides 29 groats - please insert exact fare").

In fact almost anything can be fitted into an adventure somewhere. As an extreme example, Sangraal has a 'Klingsor's Tower' puzzle, where the evil wizard Klingsor challenges the player to a wide range of contests: solving riddles, completing poems, simple games and various miscellaneous puzzles.

In summary, it's very easy to design adventure puzzles. I've never been able to solve them though.

Jonathan Partington, EUG #54