Game AI

I recently saw a link to this blog entry by Christer Ericson (of SCEA), which is a pretty amusing rip on an academic who has tut-tutted the game development community about poor AI. (Definitely check out the video linked in the blog entry to get the proper context for this entry.)

I frequently see gamers calling for more time, attention, and resources to be spent on “AI.” Unfortunately, I think the term has been diluted, such that it is now an umbrella term for a wide variety of techniques and problems, ranging from pathfinding to scripted sequences all the way to learning AIs. This may be a shocking statement to some, but I feel that what academia views as AI (tilted more towards the latter end of the scale) is not appropriate for many types of games. Actually, let me rephrase that: AI is not a good value proposition for many game development projects — the “bang for the buck” ratio is poor.

Why is this? Here are a couple of factors that come into play:

  • It’s hard to schedule “interesting AI,” partly because it can be very dependent on other systems being complete or usable to be functional at all.
  • It is difficult to quantify the benefit of “better” AI. As a matter of fact, sometimes it’s hard to decide the direction in which to move towards a “better” AI!
  • The more complicated an AI is, the harder it tends to be to test and verify. (Not always true, but this is frequently the case.)

I’m going to use the crude term “proper AI” to refer to AI more complicated than state machines and rand(), usually incorporating more academic and simulation-oriented techniques, to differentiate it from the typical, highly pragmatic game AI approaches. I feel that “proper” AI is most important for games that:

  • skew towards the simulation end of the spectrum — games that require realistic behavior in a wide variety of circumstances that cannot easily be pre-programmed.
  • have plausible ways of demonstrating different AI behaviors in meaningful ways for a player. If the player can’t perceive AI, they can’t appreciate it.

In a corridor-based shooter, for example, developing “proper” AI (capable of operating in any area of the game, with any weapon, etc.) won’t significantly enhance the gameplay experience, and so it should be shelved in favor of scripted encounters. The genre’s conventions usually dictate enemies who will be alive for no longer than 30 seconds (of fun), maximum. I don’t care what kind of “proper” AI you put into a game actor — if their lifespan is less than 30 seconds, they aren’t going to show off any whiz-bang behavior that will be appreciated by the player before they get mowed down. It’s like meeting someone in real life, where you can only get a superficial impression of someone in 30 seconds, built up from visual appearances as well as maybe a few words or sentences exchanged. Fortunately, the appearance of doing something intelligent (through scripting), combined with other cues (audio and gestures), is just as effective at projecting the illusion of an intelligent adversary as “proper” AI. Eliza could probably hold up to 30 seconds of scrutiny — for many games, that’s perfectly adequate.

For other genres, though, “proper” AI can be quite important. For example, in a flight simulator game that includes combat, satisfying gameplay is very dependent on quality AI. The perception that an enemy (or ally) is cheating in a game of this type can really ruin the player experience, and yet the AI must be competent enough to provide a sufficient challenge to a player. Simulating pilot (and electronic) perception, squad tactics and communication, and air combat doctrine may be critical goals (particularly for a military simulation).

Another genre which pretty obviously demands better AI is that of Sims-type games. The player spends a lot of time watching and interacting with agents that are supposed to be simulated human beings, so they better act in realistic and interesting ways. No surprises here.

The roundabout point that I am trying to get at is that I think it’s most useful to think of AI in games as serving the needs of a specific gameplay idea, not something that’s inherently fun by itself. It seems like many attempts at creating more “realistic” or “better” AIs for games lose sight of the fact that they don’t really make a game much better — AI researchers get too attached to the idea of “it’s really thinking!” and lose sight of the real goal of game development, which is to make fun games. Likewise, I think that forum dwellers who cajole developers to put in “better AI” aren’t seeing the whole picture either. Game developers will use better AI approaches when they can be demonstrated to better meet the needs of gameplay, and are sufficiently well-understood to lower production risks — it’s that simple.

Cold Medicines

As a recent sufferer of a nasty cold, I had my first opportunity to use nighttime cold medicines without pseudoephedrine. I bought some Tylenol Cold Head Congestion and put it to work, comparing it against the remainder of a box of Nyquil that we had which did contain pseudoephedrine.

Strangely, even though pseudoephedrine is alleged to only combat nasal congestion, I found the Nyquil to be much more effective in stopping a runny nose. The Tylenol took perhaps 50% longer to work, in my estimation, although it did eventually clear up my runny nose and allow me to breathe more freely. I would also say that the Nyquil made me significantly drowsier than the Tylenol, which I view as an advantage in a cold medicine being taken before bedtime.

I found out a little more information on the changes to cold medicines after I purchased the new stuff — apparently there is an opposite handed isomer of pseudoephedrine that does not reduce to methamphetamine, and has fewer side effects. Of course, Pfizer “has not yet sought or received government approval for its sale to the public.” In the meantime, cold medicines containing pseudoephedrine can now only be obtained from behind a pharmacy counter (and only with a prescription in Oregon!) — had I known that before looking it up, I probably would have gone that route. It just seems to work better for me — and apparently I’m not the only person who feels that way.

EA Buys Bioware and Pandemic

The story is here. Since I’ve worked pretty extensively with Bioware‘s stuff before (for Neverwinter Nights 2), I feel somehow obligated to react to this…heh. This is an interesting acquisition, and while I’m not any sort of expert in corporate finance, I do not think that this is necessarily a good move for EA. Why?

  • Some of the projects in development are risky new IP (Mass Effect and Dragon Age) — I say risky because Jade Empire, Bioware‘s first foray into the world of self-owned intellectual property, didn’t exactly set the world on fire sales-wise.
  • Some of the projects have the involvement of competitors to EA. Sega is publishing the Sonic RPG for DS, and Microsoft is publishing Mass Effect. It is unclear if Microsoft has any sort of rights of first refusal for Mass Effect sequels. It is also rumored that the MMO Bioware is working on is Star Wars-related, which would of course involve LucasArts.
  • EA was already set to publish Mercenaries 2 — by buying the developer, they’ve basically increased their risk exposure if it underperforms.
  • One of the projects, Dragon Age, appears to be a niche PC RPG. Now, while developing for the PC has the advantage of not needing to pay the console license “tax,” PC games typically do not sell anywhere near as well as console games. “Niche PC RPG” doesn’t seem to fit in very well with EA’s development philosophies — I can’t think of a single IP that EA has which they have not at least attempted to release across multiple platforms.

EA has been very keen on creating new IP to exploit — it’s a tired gaming forum cliche, but EA really is a sequel-oriented developer, and, beyond a certain threshold, sequel sales tend to dwindle precipitously. (This doesn’t apply as much to their sports games, which obey rules of their own.) So, from their perspective, maybe paying $855 million for an infusion of new ideas doesn’t seem like such a bad gamble. Given the history of some high-profile EA acquisitions of the past, though, it seems like they are risking yet another situation where the talent flees and EA is left holding an overvalued bag of IP.

Looking at it from another perspective, EA’s exclusivity deal with the NFL was rumored to be in the neighborhood of $1 billion. Does EA really think that they are going to get anywhere near the same kind of value out of Bioware/Pandemic?

CDs going away?

The Compact Disc is increasingly becoming a delivery format rather than a playback format. It’s hard for me to say when this became true for me — probably in the last couple of years, during which time I can’t remember the last time I turned on, much less used, the CD changer in my entertainment center. When I listen to music at home now, it’s always through my computer (either on its own speakers, or channeled into the Xbox 360). I still listen to CDs in the car, but I could just as easily listen to MP3s or WMAs, as my CD player supports them — and actually, to be honest, I listen more to satellite radio now than CDs. CDs in my collection mostly exist for archival and ripping purposes now — my music listening behavior has changed drastically since college, where I would select some music and set it up in my changer before starting another activity like playing a game.
My brother ripped his entire (impressively large) CD collection to a media computer, and I’m starting to think that I need to do the same thing. Apparently he’s also already had CDs that he owns go bad, and I think that I may be in the same boat. (There are a couple of CDs that I have that I know act very strange in certain players, so I’m concerned that they’re decaying. Fortunately, the ones that are suspect are not irreplaceable…)

PSA: Mountain Dew Game Fuel

It’s not bad, actually. I bought one of those fridge boxes of it, and have been slowly consuming it. It has kind of a strange aftertaste (rinsing afterwards with water is probably not a bad idea), but it’s overall fairly pleasant to drink. I can’t say that I’m clamoring for it to become a permanent variety of Mountain Dew, but I won’t throw out the rest of ’em.

I must report, however, that it did not improve my gaming skills at all. The “Perfection” achievement in Time Pilot is still just out of my grasp…

It’s Up to You

Radiohead has taken the interesting step of self-publishing their new album in downloadable form, for a user-defined price. People who pre-order the album (due October 10th) are presented with a form where the price for In Rainbows can be filled in, along with a question mark. Clicking the question mark leads to a page that reads, “It’s Up To You,” along with another question mark. Clicking on that leads to a final page that simply reads, “No Really, It’s Up To You.”

(I declared my purchase price to be two quid, which, when combined with the 45p credit card fee and the currency conversion fee from Visa, will probably wind up costing me $6-7 or so. Anecdotally, you could consider this stunt a success, then, as I haven’t purchased a Radiohead album since Kid A, which I loathed…)

I noticed that they left themselves an out — on one of the pages leading up to the album information, they say “So far, it is only available from this website.” (emphasis mine) Since there is a physical version of the album available for order (with CD and vinyl in a special collection), you would think that you will eventually be able to purchase In Rainbows in stores, much like their other albums. By starting with digital distribution through their own site, though, they will make a considerable chunk of cash off of their Net-savvy fans — much more than they would have made off of those same fans buying a CD in a store. I’m still trying to decide for myself if this is just an effective tactic for making money by cutting out the middleman, or a true shot across the bow of the music manufacturing, marketing, and retailing businesses.

The Day of Travel is Over

I’m back home again after my mileage run’s final leg back to Orange County. All flights went smoothly, with no changes or unexpected problems, although for a while it looked like the flight from Charlotte to Phoenix would be bump city because an earlier flight was cancelled. I should be getting a shade under 6,000 miles for this trip, which should be all that I need. United Premier status, here I come.

I’ll clean up my earlier posts and add photographs tomorrow — right now, I just want to eat and sleep…

Back to where I started

Hitting the wall

I am definitely tired now. I slept practically the whole way from Charlotte to Phoenix. I am also getting confused about where I am, and what time it is, which was to be expected. Just one more leg of the trip to go…

I also realized that I forgot to take a picture in Charlotte. I was planning on taking the picture in these rocking chairs they had set up in the food court, but I forgot. Darn.

On the flight from Charlotte, there was a woman sitting across the aisle from me who was traveling with a young kitten — probably 2-3 months old. I only saw her for a little bit, but the kitten was very cute. I guess if we ever have to travel with our cats, that would be an option, but I think Oliver might be a little too big for traveling like that…

Anyway, I think I may try to find a bit of food now…

Me in Sky Harbor airport in Phoenix