Thursday, April 27, 2006

Adventure Game Design Patterns


What we call chaos is just patterns we haven't recognized. What we call random is just patterns we can't decipher.
- C.Palahniuk


How about an abstract approach to adventure game design? Or at least an abstract approach to creating puzzles in adventure games - that could be useful!

The General Pattern That Adventure Games Take

Here is the general format adventure usually present:

An objective is given or hinted at.
become a ninja, save the world, rescue a girl, save a kingdom, get that guys hat ...

The objective not immediately obtainable.

Attempting to achieve objective will explain why it's currently not achievable.
the ninja master lives in Japan and you live in Australia, you don't know who bought the nuclear weapons, there's a big forest infront of the tower where the girls imprisoned, the guy with the hat has a big dog ...


The objective then splits into sub-objectives, each of those may split into sub-objectives and at the finest granularity are the puzzles. The puzzles are interesting because they're more broadly applicable to gaming as a whole.

Puzzles



Let's break down adventure game puzzle into pieces and then we can catergorise these pieces and use them as building blocks for new puzzles. Most of my examples will be culled from Monkey Island One. If you've not played it, then beware of spoilers.

We can describe puzzles using the notation below:

PROBLEM → SOLUTION.


Here's our first example puzzle to break down, it's one of the puzzles from Monkey Island 1.


One of the early puzzles from Monkey Island 1

Problem: You can't get into the kitchen because the cook always stops you.
Solution: Wait until the cook is serving the pirates food, then go to the kitchen.

We only want a rough mechanically idea of what's going on so we might formalize this as

Problem: Guardian 
Solution: Temporal

The problem is described as Guardian, to mean some entity prevent you from taking a certain action.
The solution Temporal means you must do some action at a given time - maybe at night, or on tuesday or when someone is distracted.


You can probably think of several puzzles that could fit into the above slots, and that's why I think looking at these puzzles is a good idea. We could expand the above formalization to dictate what's being guarded:

Problem: Guardian(location) 
Solution: Temporal

Let's move on to a list problem types and solution types that I've identifed. Then we can go through some examples of how to use them.

Problems



Problems can be a little fuzzy in their boundaries.

Guardian
There is a FOO stopping you from doing something, it may block a location, it may be guarding an item, or an NPC.

Typical Example: The bridge troll guarding a bridge.
Non-Typical Expample: Bad breath guarding an NPC - you won't talk to him with bad breathe.

Want FOO
Your character wants or needs something but cannot directly get it. This maybe knowledge, money, training, ...

Typical Example: The sword costs 300 gold.

Key Request
To proceed the character must have a certain item. The character might need a password, to be part of certain group, to have certain clothes, ...

Typical Example: A locked door that requires a key.

Temporal Item
An item that you need to use keeps dissapearing before you can use it. Maybe you need a gold key to open a door in the thieves market - but it's always stolen when you get to the door, or you need to transport acid but it dissolves the container.

Typical Example: ?

Hidden FOO
This is a problem the player might be unaware of and it's potentially a very hard problem. There's an item, destination or NPC that the player needs but it's somehow hidden. A file in a cake, tree house city up a tree trunk, secret passage, long lost master trainer... you might need a microscope, telescope or something that allows you to see the hidden thing, or you might need to pick up or move a concealing object.

Typical Example: File in a cake.

FOO out of reach
You can see, smell, hear, see evidence or have been told of FOO but you can't physically get it. This is closely related to want FOO. Maybe it's too high up, or maybe you can't catch it. Think a mouse, or a parachute in a tree, or a treasure chest deep under water, a monkey with a gold ring, a lost city, an island, the moon.

Typical Example: A box on a top shelf that you can't reach. The fabled city of gold.

Trapped
You character is in someway trapped and needs to escape, perhaps locked in a room, a cement block on their feet and sinking underwater, tied up and all the variations on the theme.

Typical Example: Thrown into prison.

Approaching Danger

If you stay where you are and do nothing you will die (or similar). Think of an oncoming flood, you're underwater and going to drown, there's a biker gang approaching, the police are coming for you, there's an evil alien after you, the ground is crumbling, the bombs going to go off, angry bears, BEES! (Can sometimes be similar to trapped.)

Solutions



A problem may have more that one solution or a combination of solution pieces.

New Item Perception
An item must be seen in a new light, that pot could be helmet, the bat could be boomerang, this is something the user has to understand in their head, or it be required that the character formally understands this knowledge. For instance you may need to look at the bat, then the character might say "Hey looks a bit like a boomerang" then the game will promptly rename it baaterang and you will now be able to use it as different item.

Typical Example: Water as a mirror, Paper clip as lock pick.

Combine Items
You need to combine, two, usually inventory, items to produce a more useful item. Poison and meat creates drugged meat, cat hair and glue creates fake side burns, gold foil and a toy badge creates a police badge ...

Typical Example: Poison and meat to create drugged meat.

Trial and Error
Generally something to be avoided but can be an amusing distraction. What's the correct offering to hillside tribe, how should a certain machine be adjusted or put together, what order should three levers be pressed in, how should a conversation tree be navigated.

Typical Example: Pull three levers in the correct order to open the door.

Obvious Item Use
Using an item straight forwardly on something other object, or performing a straight forward action to an object. A key on a door, the fish with the troll that wants fish, the money with the shopkeeper.

Typical Example: Give money to the shopkeeper.

Change Item State
Very closely related to obvious item use but specifically items that will change the current item - eating a cake, smashing a glass, burning wood to get charcoal, cooking raw meat, opening the box...

Typical Example: Eating a cake to get a file. Opening a container

Temporal
Warning this can be a very difficult solution, you must do a certain action at a certain time - enter the kitchen when the chef isn't looking, scarifice the virgin when there's full moon, spit when the winds blowing with you, throw the bomb when the gas fire goes out ... at all other times the action will fail.

Typical Example: Enter a room when the room owners isn't there or is distracted.

Monkey See Monkey Do
This is quite a general meaning - you might see a NPC give a password, well then you follow his lead and say the same word, or you might see him do a combination, or you might physically follow him down the streets to see where he goes.

Typical Example: Follow the NPC to his secret place / treasure.

Repitition
Do the same action more than once, it won't succeed on the first action but will succeed on a subsequent repition. For example a wooden door kicking it once may do nothing, the second time you kick it it might break, you might have to ask an NPC about something twice to show that you're really interested. These solutions can also be quite difficult.

Typical Example: Breaking something, smashing a bar window with a hammer for instance, chopping down a tree with a saw.

Spatial
Can be even more difficult than temporal. An action will only succeed if the character is in a certain place, avoid the patrol by standing in the shadows, shoot the apple by standing on the hillock, be behind the man when you hit him with the bat ...

Typical Example: Hiding in the shadows so you can't be seen.

Bait Item Use

Different than obvious item use. With obvious item use we give the fish-wanting-troll the fish. With bait item use we throw the fish in the river and the troll jumps in after it. We "bait" the river. Bait Item Use, indirectly solves the problem - something nearby is interacted with in the hopes it will distract or remove the problem. Throwing a rabid chipmunk into a chefs kitchen so you can steal his wash cloth, putting cheese in a mouse trap, putting an attractive women across the road to make a bouncer move away from a door.

Typical Example: Cheese in a mouse trap to catch a mouse you cannot directly catch.

Real World Knowledge

The puzzle requires some aspect of real world knowledge. This includes nearly every puzzle but this pattern highlights a puzzle where it's especially true. Formulating a chemical compound, using magnets to move metal objects, knowing the to syphon petrol you usually start by sucking the pipe with your mouth, that a strong magnet will wipe a video cassette, that salt wards off evil ...

If the knowledge required is too obscure it may make the game very hard.

Typical Example: Balloons are often filled with helium, helium is lighter than air, helium can change your voice.

Sabotage (high level)

Stop something working, prevent something from happening, if you want to get a better job in a company you might sabotage the competition using laxatives in there drink, talking to them, distracting them with a light, you could remove a cars spark plugs, put a penny on train tracks ...

Typical Example: A spanner between two cogs.

Common Puzzles



The Trade



Trade is a resticted version of:

Want Foo -> Simple Item Use

It's only where to get something you must give something first, so it's more commonly.

Want Foo -> Simple Item Use (give)

You want the magic axe but the warrior wants a replacement weapon before he'll hand it over. This is the nornal trade puzzle. It's not really a trade puzzle if you can hit him on the head with a spade and then take the axe which is what the unrestricted Want Foo -> Simple Item Use would allow. Unless you say you were trading a blow on the head with a shovel for an axe ... but I think the warrior may want to dispute that.

Need To Travel

A special case of FOO out of reach, where FOO is a location. Think Monkey Island in the secret of Monkey Island. Or the secret herb patch in a forest.

FOO out of reach(location)

The solution maybe be a long series of puzzles.

Some notes about the above catergories



All catergories are human invention and exist only in our heads. Few catergory systems are perfect. Some puzzles are better and more satisfying than others. The main problem with this is that it does not differenciate between good puzzles and lack luster ones. So with that said there are a few I'd like to focus on here:

I think in Monkey Island 2 you had to close an open door to find something on the back of it. At the time an extremely tricky puzzle because it's an easily overlooked thing.

The same kind of thing with picking up an item that you would imagine to be unpickupable such as a poster on a board of other posters. The poster might be useful in itself or reveal a hole or a different poster.

It's worth noting this list doesn't say much about fashioning a good game either. For instance in monkey island one there's some great foreshadowing where you get money from the circus for being fired out of a canon with a pot on your head, then later you fire yourself out of a canon with a pot on your head to get to Monkey Island.

Big Example List



These examples are culled from Monkey Island 1, if you haven't played the game yet I advise you miss this section out.

Release the prisoner - Monkey Island 1

The prisoner is stuck in his cell. Grog will dissolve the bars lock, unfortunately it also dissolves the cup. To solve this problem you must keep transfering the grog from cup to cup.
Problem: Temporal Object 
Solution: Repetition, Combine Items

You must repeatedly transfer the grog from cup to cup.

Canon Job - Monkey Island 1

You wish to get fired from a canon for money but your potential employers are unwilling to fire you without a helmet. You give them them a cooking pot and they agree to fire you.

Problem: Key Request
Solution: New Item Perception, Obvious Item Use


Guardian Dogs - Monkey Island 1

There are dangerous dogs blocking your path.

You must realize a petal causes sleep, then you must combine the petal with meat then you must give the drugged meat to the dogs.

Problem: Guardian
Solution: New Item Perception, Combine Items, Obvious Item Use


Getting a birds fish - Monkey Island 1

A bird is eating a fish on the dock. You want the fish but everytime you approach it flies away with the fish. If you stand in a certain place, a board rises and hits the bird knocking it away - leaving the fish for you.

Problem: Guardian
Solution: Spatial Location


Swordsman Training - Monkey Island 1

You want the swordsman to train you but he won't do it unless you have a sword and give him money. Once you have the sword you must show him and once you have the gold you must give it him.

Problem: Want FOO
Solution: Obvious Item Use (gold), Obvious Item Use (sword)


Trapped - Full Throttle

At the start of the game you're trapped in a dumpster.

Problem: Trapped

If you punch the hatch it will open, freeing you.

Solution: Obvious Interaction.

Want To Enter A Trailer - Full Throttle

You want to enter a trailer, there's a door and a man stopping you, he won't let you in.

Problem: Guardian

If you kick the door when he's talking you'll kick the door down and flatten the guy in the trailer.

Solution: Temporal + Obvious Item Interaction

Dog Guarding the Junk Yard - Full Throttle

Everytime you go to pick up something the dog stops you.

Problem: Guardian

To get rid of the dog you have to remove by throwing meat in a car, the lifting the car with a magnetic crane.

Solution: Bait Item Use, Real World Knowledge(magnetic cranes are for moving cars) + Obivious Item Use(crane)

You can't get into a Locked Room - Full Throttle

You cannot seem to get into a locked room. You may not know, though you may guess, that this is because an item is hidden from you.

Problem: Hidden FOO

The solution is to move a pillow and find a crowbar, for now I'm putting this as obvious item use though I might change it.

Solution: Real World Knowledge(people put things under their pillows), Obvious Item Use(move, pillow)

Final Thoughts



Spatial, Temporal and World Knowledge are best used as modifiers on the other solutions.

I think the list is quite interesting and if you think you've can regcognize anything similar I'd be interested to here. I intend to go through a few adventure games and see what I can find.

*I changed simple item interaction to obvious item interaction to reduce the scope. Some of the examples now read a bit weird.

Notable abscences are timed problems also I found it hard to categorize the sword fighting and insult collecting with pirates and then later using those collected insults in a new situation with the swordmaster.

PuzzleFamiliar



Here's a program that will create puzzles patterns for you to fill out. All the patterns are documented there too.

PuzzleFamiliar.zip

You'll need the .net runtime. Though it's quite likely you already have it.

8 comments:

Anonymous said...

Great stuff!

Anonymous said...

Very interesting. I linked to the article from my blog.

Anonymous said...

Heh, again, this is bloody good. Keep up the good work!

I love these kind of articles - and it's reminded me of something I'd been thinking about. In Zelda, and how the puzzles are handled in it - there's only so many objects, and so many ways you can use them, but there hasn't been a Zelda yet that hasn't made me slap my forehead and curse myself for taking so long to see the obvious.

Have you ever read The Big List of RPG Plots? Like this list, it breaks down a genre to it's core components, only in this case, it's dealing with typical RPG plots. Well worth reading.

Anyway, kudos!

balaam said...

I'm sure Zelda games would be interesting to look at too :D

I've seen the RPG plot list I think I found through this
rather interesting post on automated story telling.

Anonymous said...

This is a great blog feature! I'm always interested in reading what other people think about adventure game design. (I've dabbled amateurly in it off and on for years now.)

Your patterns entry reminds me of a list I made called "50 Game Design Mistakes". It touches on a lot of what you said, but it focuses on some of the more negative aspects (i.e., NPC's who apparently have amnesia and therefore don't remember having already talked to you before.) Though some of what I call "mistakes", others probably see as fun. (Example: most trial-and-error lever puzzles.)

VictorL said...

Thanks for the post. I just got into your bloh, i'll keep comming.

Victor.

PixelArtist said...

Fascinating article!

Where did the link to the .zip file go? I cannot download it...

balaam said...

Yes I think interesting I'd like to have a look at it again and maybe develop it in the future.

The link was stored on a friends old hosting, which he had since stopped paying for. I think I have the original around some - but it's probably better done as a web app now anyway.