Slashdot Mirror
Adventure Game Interfaces and Puzzle Theory
MarkN writes "It seems like whenever broad topics of game design are discussed on Slashdot, a few people bring up examples of Adventure Games, possibly owing to the age and interests of our members. I'd be interested to hear the community's thoughts on a piece I wrote on Adventure Games, talking about the evolution they underwent in terms of interfaces, and how the choice of interface affects some aspects of the puzzles and design. My basic premise is that an Adventure Game is an exercise in abstract puzzle solving — you could represent the same game with a parser or a point and click interface and still have the same underlying puzzle structure, and required player actions. What the interface does affect is how the player specifies those actions. Point and click games typically have a bare handful of verbs compared to parser games, where the player is forced to describe the desired interaction much more precisely in a way that doesn't lend itself to brute force fiddling. It's a point Yahtzee has made in the past; he went so far as to design a modern graphic adventure game with a parser input to demonstrate its potential."
Read on for the rest of MarkN's comments.
MarkN continues:
"In addition to talking about the underlying concepts of the genre, the other main thing I touch on are the consequences of the simplification of interfaces — puzzles are more likely to be cracked by trying everything until it works since there are fewer possibilities for interaction. There are a few simple alternatives: requiring a number of actions in sequence, or requiring the player to achieve a more complex configuration or state to demonstrate their intent. But that can reduce the world of puzzle solving to explicit logic puzzles in order to get around the problems that more creative types of puzzles run into, since they depend upon actions that are simpler to specify. It's a topic I'd be interested to get the community's thoughts on, and what they see as the best way to craft a puzzle solving experience."
"In addition to talking about the underlying concepts of the genre, the other main thing I touch on are the consequences of the simplification of interfaces — puzzles are more likely to be cracked by trying everything until it works since there are fewer possibilities for interaction. There are a few simple alternatives: requiring a number of actions in sequence, or requiring the player to achieve a more complex configuration or state to demonstrate their intent. But that can reduce the world of puzzle solving to explicit logic puzzles in order to get around the problems that more creative types of puzzles run into, since they depend upon actions that are simpler to specify. It's a topic I'd be interested to get the community's thoughts on, and what they see as the best way to craft a puzzle solving experience."
Most of them when I played them back in the 90s seemed to require the following player input:
find monsters
kill monsters
level
And then when you go to a high enough level
find newbies
kill newbies
run from angry wizards
And that was about it.
I once had a similar debate while discussing with a guy who was doing a nethack port on the Game Boy Advance platform.
Nethack is a keyboard-driven game, where you specify actions (go, eat, attack, loot, force, open, close, zap...) by pressing a given key before you specify the object upon which your action is performed (if any), thus taking advantage of the large number of keys available on an average keyboard.
Console RPGs have a limitation in input keys : on the game boy advance, you only have 8 useful keys (directional pad, A, B, left and right shoulder keys).
So porting nethack to the Game Boy Advance platform required either simulating the keyboard in some way, which was the approach of the guy I was talking to, or defining a different interaction paradigm.
In console RPGs you usually specify objects before you specify actions. The reason is simple: objects, displayed as a list, are easy and fast to browse with directional keys. Then for one object you select, you get to select which actions is available for performing on that object, once more a small list, fast to browse with few keys.
So I ended up figuring out that the best way to port nethack was to actually invert the interaction paradigm, going from action->object to object->action.
For the player, it meant that the game would be played in very different ways. You don't think "what am I going to do now?" but "what can I use at this point to do something?" Still, the game engine is the same...
I really miss the interfaces the older adventure games used, like Police Quest 1 and 2, Space Quest 1 and 2, Leisure Suit Larry 1-3, and the other Sierra adventures from that time. Just walking around, and typing instructions. Of course this could be modernised by using voice commands, but I like it better than just clicking around on everything until the right thing is clicked.
I think one of the biggest hurdles with adventure games, which the article touches on, is the fact that it's hard to make a complex world that is still easy to navigate.
For example, I love the idea of Sherlock Holmes games but often they devolve into a laborious click frenzy where you start investigating every object in the environment in the hope that it will be somehow relevant.
Similarly, how many people here have played Resident Evil and spent a lot of time walking awkwardly against the walls while mashing the X button?
I think the most successful adventure games are those that can make their world seem at once complex and immersive yet still easy to navigate and explore without becoming an exercise in endless clicking frustration.
When I was a kid (30'ish years ago) my brother and I would go to the arcade, primarly to watch the older kids play games (I was terrible at them, so it was interesting to watch.) There were a handful that always struck me as the most interesting and those were the ones with the unique interfaces: Centipede and Missle Command, because of the trackball, Tempest because of scrolling wheel (which reminded me of Pong) and some kind of crossbow game where the player grabbed a replica crossbow. But there was one other, and to this day I have yet to find anyone who doesn't think I'm nuts when I describe it: It was an adventure game with multiple players with multiple classes where the players used a keyboard (one of the membrane ones, like the second generation Speak & Spell.) I always thought it odd that a play-for-quarters game would be so complicated that it required its players to actually have that many selections so as to have a way of actually completing the game (don't ask me to describe what was on the screen. I was too short to actually see it :)) To this day, I don't think I've seen another like it, without actually transitioning to a PC.
Bark less. Wag more.
For that reason, adventure games are more than mere problem / puzzle solving games. They require of the player some skills to hack around inside the source (or to know someone who has) to get the most out of them.
As for versions written since the early 80's - I haven't a clue. They all seem to be variations on the earlier theme, so once the (original) problem had been solved, they held no interest for me.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
Not to be mean, but have you ever played Nethack seriously ? ...) but if you want to wield another object such as a potion, a monster corpse, or anything else, you can do it and you may discover interesting effects with this.
What you say is wrong because, Nethack doesnt limit you, you can try any action with any object (it may lead to nothing but at least you can try to do it). You select an action, it suggests obvious choices but you can also try everything else.
For example, if you want to "wield a weapon" (== "equip a weapon"), the game suggest items that obviously qualify as weapons (sword, bow,
My point is, if you go from action->object to object->action, you would still have to display all the objects available and then display all the actions available : you didn't reduce choice or the difficulty to navigate the interface at all.
"So I ended up figuring out that the best way to port nethack was to actually invert the interaction paradigm, going from action->object to object->action."
So you translated it into German!
"clicking your hand icon on a tree isn't much different than 'climb tree.'"
I disagree. Clicking your hand icon on a tree could mean innumerable things, some of which I might never think of. 'Climb tree' 'pat tree' 'touch tree' 'rub tree' 'get bark' etc etc.
So a graphical game will inadvertently hold your hand and help you along, where a text parser makes you figure it out.
Don't get me wrong, I like both kinds of games. Hero's Quest and QFG 1 VGA were both great games. But clicking and typing aren't the same at all.
"If you make people think they're thinking, they'll love you; But if you really make them think, they'll hate you." - DM
I can't confirm or deny your sanity, but the game did exist (though it wasn't very popular). The game was called Thayer's Quest.
Support Right To Repair Legislation.
A very good article. The author knows his adventure games.
The whole concept of "the underlying game is the same, just presented through a different interface" isn't really true. I find that the different interfaces make way to whole different sub-genres of game.
For instance, consider the point-and-click style Sierra / Monkey Island games, in which you have many verbs and inventory. Such games tend to be very much object based and character based. All of the puzzles are about either a) using the right object in the right way with the right target, or b) choosing the right dialogue path.
Compare this to the first-person Myst-style games, which are all left-click based. No inventory, only a single verb. Well these kind of games tend to have very few characters for one thing. The character interaction is usually limited to cutscenes, as opposed to dialogue trees. The puzzles tend to be more mechanical (figuring out how to make certain devices work) rather than purely logical. The solutions tend to be more about what this author calls "implicit information" - having to write down passwords rather than carrying keycards.
For example, consider that you are stuck in a locked room. In Myst, you will probably see some kind of complex lock mechanism, and have to figure out its controls, and how the device works, and then "hack" the device to open the door. In Monkey Island, you will probably be interacting more with the environment; have to use some item you find in the room or already have in your inventory, or bribe the guard by choosing the correct dialogue.
I think the interface directly influences the style of gameplay. For example, the Monkey Island interface is nowhere near complex enough to let you figure out the workings of a locking mechanism in the Myst style, and nor does the Myst interface have the ability to let you use items on the environment or have a conversation with a guard.
I think it's more likely a lack of imagination on the part of designers. The fact is the basic building blocks of the design are fundamental.
Stephen Poole made the point that the more things Lara Croft became capable of in the Tomb Raider games (climbing ladders, auto aiming etc.) the more bizarre it seemed that she couldn't use the rocket launcher to blow wooden doors off their hinges.
I think a lot of times the reason puzzles devolve into an endless series of finding blue keys for blue doors is not so much because of an inherent problem in the interface but more because the designers can't be bothered to think of creative uses for that interface. Not saying that I can necessarily but nobody complains that you can solve Sudoku puzzles with a bruteforce online tool. The point and fascination for the participant is that it's more entertaining to do it without just cheating.
If your game isn't entertaining enough even if someone knows every answer ahead of time it sure as hell isn't going to be made more so by the addition of High IQ required brain busters.
www.nodicerpg.com - Some RP stuff for free, some not so for free, but still cheap.
I think a critical part of the purely text adventure is the narrator, i.e. the responses you get to any and all of your actions. In many cases, that omniscient voice is there not just to describe the environment, but to give (perhaps subtle) clues about what was possible and what was fruitless. A lot of the time, with just pointing and clicking, there's precious little feedback except success or failure; the mashed potato example in the parent post is (to my mind) much more rewarding. The recent game "Violet", winner of the 2008 Interactive Fiction Comp (playable via Parchment) has one of the best narrators I've ever encountered.
Slightly disreputable, albeit gregarious
The more complicated they become, the larger the advantage becomes to those who look up the solution.
I'd like to submit as a counterexample the Zelda series. To put my words in the right context: I have completed Twilight Princess two times (I own it), and my gf.ex[2] had Ocarina of Time, which I played most of a good while ago.
For those of you who don't know (srsly? on /.?), it's single player. Your HP is measured on a scale from 12 to 80 (quarters of hearts), with most attacks inflicting 1 or 2 points of damage. You character "levels up" by finding items or by collecting hearts; you get a full heart container for beating a boss, and can find shards hidden in the bushes. The game has a fixed set of items: four bottles, a fishing rod, a bow plus arrows, a ball on a chain, a pair of iron boots, bombs etc., which you find at various story points; some of the bottles are hidden and found by off-storyline investigation, and some items or item enhancers (a bigger quiver) are found in side quests.
Combat is fairly easy. Even for the bosses, you fairly quickly learn how to dodge their attacks and stay nigh-invulnerable, plus there's typically a big stack of hearts available if you look around. This minimizes the impact of gathering combat gear. [one exception is the Cave of Ordeals which is pure combat, tons of fun, and completely optional].
That's for the character progression. It tends to be either (1) in lockstep with the story, or (2) not very important; something you do for completeness or (future) convenience.
The main focus, not being on combat or character progression, is on solving puzzles. Each item has between (roughly) one and three important characteristics that outline how you use them. For instance, the iron boots make you heavy, slow and give you a lot of friction. The grappling hook lets you pull objects close to you, or you close to objects, and have a limited range; it also hits the object it impacts with and travels in a straight line. The bow hits the object it impacts with, doesn't move any object, has a limitless (for practical purposes) range but shoots in a parabolic curve.
The trick is to figure out how to combine your items with your environment. In one dungeon, you jump and grab a hold of a handle hanging down from a ceiling, but nothing happens. If you put on the iron boots, you become heavy, pull the lever down, and activate something. In a later dungeon, you use the grappling hook to "jump" to a chandelier, then put on the iron boots to do the same trick.
So, each object is fairly simple on its own, having typically only a single "wear" or "use" verb (and rarely both), but complexity arises from their combination and their interaction with the environment. I think that's a fairly good of building a rich system from simple components.
The puzzles can get somewhat complex. For instance, there's a sliding block puzzle: some (~3) block reside on a frictionless ~6x6 chessboard with some squares cut off and walls on the edges; you can exert an axis-parallel force on a block, including from outside the board, but not from inside another block. Your goal is to move a subset of the blocks onto some marked squares. (think of sokoban with sticky arrowkeys and the player inside the walls if it helps you). They can get fairly demanding; less straightforward than "go kill diablo".
Yet it's one of the highest ranked games at that site which averages out other reviews.
How come?
Well, the story itself is nice. It's fairly simple:
SPOILER WARNING ... but the characters are interesting and it's told in an interesting way.
The villain kidnaps the princess
SPOILERS END HERE
I posit this hypothesis: by emphasizing story progression and a sense of achievement (from solving puzzles) over greater combat ability (from MF'ing and tediously but trivially earned leveling), there's less to be gained from cheating--you're cheating yourself out of the feeling of accomplishment, and all your getting is a nice story and the possibility to cheat yourself in the future.
If you want a really good comparison of interface versus depth of a game, compare Black Isle's Fallout 2 to Bethesda's Fallout 3. Fallout 3 fails to have any interesting puzzles, and very little character or plot depth. It's pretty enough, and a 3-d (if buggy) environment - and they did a good job with the real-time/turn-based hybrid interface. On the other hand, Fallout 2 is a pearl of humor and interesting character choices - not just a black and white, good versus bad spectrum.
I hope we can get through this dark period of games quickly, to a day where the tools are well developed enough that we can have some interesting writing again. The market these days is comprised of mostly of FPSs, MMOs and flash games, it seems.
[Ego]out
That they killed Floyd. Man, that just crushed my whole life. I haven't been right since... that shaky, almost annoying robot, so brave so suddenly, about to go into that room. Planetfall, you broke my soul.
This is my sig.
Pedantic Man to the rescue!
You cannot attempt to [W]ear most items in Nethack. If you type W with no armor available, it will tell you that you don't have anything else to wear. Similarly, you cannot [P]ut On non-accessory items--if you type P and have no accessories, it will tell you that you don't have anything to put on. It doesn't even give you the option to select an item. [q]uaffing works similarly.
If you have an item of the appropriate type, and you type P, q, or W, and you select an item of an inappropriate type, it will tell you, "That is a silly thing to [wear|put on]." I suspect that this is to simplify the code, rather than so that you have perceived freedom of action. Otherwise, you should be able to select items even if you have no legal items from which to choose.
In other words, I don't think it's too far outside of the spirit of the game to go object->action, however you absolutely have to account for every legal action. You can exclude a Wear action for arrows, for example. However, this might provide clues to the player for some actions, and may ruin the gameplay experience. For example, if the player selects a potion, and notices that he has the option of wielding the potion, it takes the joy out of discovering this particular option yourself.
Considering adventure games just as a series of puzzles is really missing the whole point. The main objective of adventure game is to tell a story, the puzzles are merely a way to engage the player into the world, not a means to an end. And the important part isn't really if you have one or three verbs, but how well the puzzles integrate into the gaming world and how believable they are, many of todays games fail at that, leaving the player with awkward puzzles (tape mobile phone to cat).
Another thing is that the three verb interface didn't just reduce the number of verbs, but it made the verbs more organic. In The Longest Journey or Full Throttle for example you don't have explicit verbs, but body parts. You have a "hand" action, a "mouth" action and a "eye" action for example. "Mouth" is not only used for talking, but also for drinking potions or sucking on a hose to get fuel out of a tank. So the whole game becomes a matter of combining objects instead of applying specific verbs to objects.