Drop me a line or reply to this post if you want access to the Google Analytics information for pcg.wikidot.com. Unfortunately, the permissions model for Analytics as I understand it means I can only give View Only access without having to throw away all the historical information and starting again.

Regards,

Andrew Doull

Julian Togelius has set up a Google group for PCG at http://groups.google.com/group/proceduralcontent which appears to already have more discussion other than housekeeping than the forums here. I'd like to invite regular contributors to join the group - I suspect we should perhaps have a brief poll here on whether we should close down the forums here other than the General Discussion forum.

Regards,

Andrew

I'd surely consider AI content though, the difficulty and complexity of which certainly affects the enjoyability of the game. I'd say only include games that feature adaptive AI as a major feature, like Left4Dead.

On the topic of Left 4 Dead, could you point me to a description of its adaptive difficulty, if you happen to have one? Because my limited experience with the game seems to suggest that what the AI Director is more an example of Algorithmic Difficulty, rather than adaptive….if I try to play a campaign on a difficulty that is too high for me, I will just fail the campaign. Likewise if I play on a difficulty that is too easy, I will run through it unchallenged. The AI Director may place the zombies in new locations each time, or order in zombie waves in different locations, but if I opt to play a hard campaign, then the AI Director will algorithmically give me a hard campaign.

A lot of the press about Left4Dead mentioned it's adaptive difficulty - [http://www.edge-online.com/blogs/gabe-newell-writes-edge] is probably the easiest example to find. I'll add it to the article.

From the 'What PCG is' page, you have created this as your base definition of PCG:
"Procedural content generation (PCG) is the programmatic generation of game content using a random or pseudo-random process that results in an unpredictable range of possible game play spaces."

A potential problem with adaptive difficulty as a PCG technique is that rather than allowing the player to explore an 'unpredictable range of possible game play spaces,' the goal of adaptive difficulty (as I understand it) is to constrain the player into the game designer's preferred play space. That is, if you are too good at the game, the game will get harder, so that you progress as expected. The same is true of the 'too bad at the game' case.

Take Resident Evil 4, for instance. Much of the tension, the overall 'experience,' in the game comes from managing a small amount of resources, primarily ammunition. Therefore, if I, as the game designer, want to ensure that a certain scene or boss 'feels' right, I need to make sure that the player has a given amount of ammunition when entering the fight, so that they get the experience I designed for them. By adding adaptive difficulty, I introduce a nice negative-feedback loop which prevents players from straying too far from this 'optimal' play space, by either removing excess resources if the player is too good (and thus has an abundance of ammo) or by adding in resources if the player is too bad (and is running the risk of leaving the game out of frustration).

Next look at Oblivion. The adaptive difficulty in this game, as far as I understand it, scales the monsters' levels with that of the player. So if I approach a tower at level 1, I will fight a level appropriate enemy. Similarly, if I approach that same tower twenty levels later, the enemies will have leveled up appropriately (perhaps the bandits have full plate mail and magical swords instead of cheap daggers and torn clothing). Now, again, this adaptive difficulty serves to focus the game into a very comfortable and safe player space…I will always be able to vanquish my enemies, provided I put in approximately the same amount of effort as I did previously. This adaptive difficulty removes the player's ability to explore the more 'dangerous' parts of the play space in favour of keeping the game friendly and playable. Now, this may have benefits for many players (I personally disliked the leveling world), but as far as resulting in the exploration of an "unpredictable range of possible game play spaces,' Adaptive Difficulty, as I have seen it implemented, seems to be designed to do the exact opposite: to allow the designer to better control the player experience.

On the topic of Left 4 Dead, could you point me to a description of its adaptive difficulty, if you happen to have one? Because my limited experience with the game seems to suggest that what the AI Director is more an example of Algorithmic Difficulty, rather than adaptive….if I try to play a campaign on a difficulty that is too high for me, I will just fail the campaign. Likewise if I play on a difficulty that is too easy, I will run through it unchallenged. The AI Director may place the zombies in new locations each time, or order in zombie waves in different locations, but if I opt to play a hard campaign, then the AI Director will algorithmically give me a hard campaign.

Anyway, I hope I've at least provided a decent springboard off of which to continue thinking about the issue of adaptive difficulty as it relates to this wiki.

I've hit a stumbling point writing up an article on adaptive difficulty - always a controversial point in games. I'll quote the whole article to saving you having to go to the original link:

Adaptive difficulty is the process of adjusting the game in reaction to the player. By spawning new enemies or powering up existing enemies if the player is progressing quickly through the game, or by decreasing the frequency and/or difficulty of existing enemies if the player appears to be having problems progressing, adaptive difficulty techniques attempt to create the 'optimal' game experience.

Classically, adaptive difficulty has been seen as a hard problem, requiring a level of artificial intelligence in the game to attempt to model the player to attempt to determine if they are finding the game easy or difficult.

However simpler RPG style mechanisms can also be seen as adaptive difficulty techniques. Allowing the player to level up by playing through additional easier content can ensure the player is able to grind their way through parts of the game in order to decrease the difficulty of sections of the game where the difficulty level increases. Paradoxically, adaptive difficulty techniques which increase the difficulty of the game by scaling up enemy strength have been fiercely resisted by RPG players, as can be seen by the negative reactions to the difficulty scaling in Oblivion.

Adaptive difficulty is not usually seen as a procedural content generation technique, but it has most of the features of such techniques. It could be seen as decreasing a game's randomness instead of increasing it which would make games which feature it without other PCG features to fall outside the 'canon' of PCG games.

Should I include games which have adaptive difficulty in the PCG wiki? There are plenty of examples of games which have adaptive difficulty and are procedural (Oblivion I've already mentioned, Left4Dead) but there are plenty of games which are not (SiN: Episodes). And I don't want to include every RPG, based on the argument I've made above.

The real question is not whether I should include these games, and the answer to that is probably not, but why? What good reason can I give to not include SiN: Episodes, for instance, as a procedural game?

Again, the randomness argument is the most plausible, but it is not completely convincing.

Convince me.

I'd love to be there…

Thanks to whomever set those up.

Having set up a fairly rigid taxonomy of thinking about PCG types, I think it's time to break it down. There's a couple of reasons why:

1. It's too difficult to spell taxonomy.
2. I've created this pcg-algorithm: _concepts tag and want to use it.

So if no one has any objections in the next couple of days, I'll move these across.

Of course, there's an equally valid argument to go 'why are these algorithms at all?'. They're not. They're higher level concepts. But they lie close to algorithms on the thinking about 'how do I implement the creation of procedural concept.'

Thoughts?

Andrew

The FlickrGallery module is kind of neat but could still use some work. There are two features that should exist, might not take to much work on the part of wikidot:

1: allow tags to be negated: that is we want to exclude all images that have certain tags. This isn't a big issue but would be nice. I filed this as a bug but that probably isn't the correct place to put it.
something like:

 [[module FlickrGallery tags="procedural" excludeTags="unicorns" tagMode="any"]] 

2: allow tags to be combined with "alternative attributes": photosetId, groupId, groupUrl. If this was implemented we could use the gallery to populate other pages. (An expamle is fractal. Using tags only there are many images there that are not proceduraly generated (such as photographs of plants) and very few have any explanation as to where they come from. There are images in the flickr group pool that have the tag fractal and it would be nice if we could show them that page.)

 [[module FlickrGallery groupId="1153986@N23" tags="fractal"]] 

Whether a wiki should in and of itself be the vehicle to promote discussion, I am not so certain. Perhaps more proactive endeavours better suited to engaging people would be better suited. One thing that comes to mind is perhaps informal challenges where people are encouraged to implement some usage of a procedural generation technique, in friendly competition.

Anyway, this is my plan. Any thoughts?

At this stage I don't know if we have enough content yet for a clear style to have emerged… but a less formal style is fine by me.

I am not the first to speak of this:

Flammifer:

I gotta admit, the Wiki as it is doesn't really encourage community discussion. It has a bit of an encyclopedic tone, it might work better with a more informal tone, like tv tropes and, well, most good non-wikipedia wikis :)

andrewdoull:

Feel free to give the place more of a community vibe.

So we should be using an informal style. Don't take the long, dry, and boring way to explain something just because this is a wiki. Say it as it is, or at least say it how you would normaly. No need to use fake voice. This is the tone. I wish I could be more specific, but this is a bit unclear to me.

On the other hand, I want my writing to be written for the web. This is the style:

• Consise text. Fewer words are better words. Make every word count. (Strunk and White FTW!) Use half the word count (or less) of conventional writing. This could compete with the tone but if it makes the content easier to understand then all is well.
• Scannable layout. Use bulleted lists where they work, bold key phrases, and otherwise make it easy to find out what an article is about without actually reading it. This means
  • highlighted keywords (hypertext links serve as one form of highlighting; typeface variations and color are others)
  • meaningful sub-headings (not "clever" ones)
  • bulleted lists
  • one idea per paragraph (users will skip over any additional ideas if they are not caught by the first few words in the paragraph)
  • the inverted pyramid style, starting with the conclusion
• Objective language. Prefer neutral, descriptive language over subjective boasting. Marketese (aka doublespeak) causes mental friction, it slows down reading and sows distrust. Again this could compete with the tone but it shouldn't. The big point is to be honest and don't sound like you are selling something.

Anyway, this is my plan. Any thoughts?

You may want to have a look at the gallery module in the wiki syntax for a useful way to display this. However:

Allowed "per-image attributes are: * link - URL or wiki page name (does not work with Flickr images to be o.k. with Flickr terms)