Game AI vs Traditional AI

I have an academic and professional background in traditional AI, and I've programmed an AI for a 3D video game I made in college. My traditional AI background is mostly in applying a wide variety of mainstream machine learning algorithms, including neural networks, SVMs, and regression, to real world problems like fraud and image detection. I was somewhat frustrated when building the game AI because the best solution came down to building a large state machine with hard-coded logic. The AI was dead-simple, but it worked well and wasn't too far from state of the art in video game AIs at the time, and I suspect today.<p>I agree with the general point of this article; in fact, I think it understates the case. When people want AI in video games they want the AI to be truly smart. The fact is, we haven't cracked "intelligence" yet. Most of 'AI' research has veered into machine learning, which is basically applied statistics. While this algorithms can solve many constrained problems quite well (this field powers much of google search) it's tough to frame complex problems like a 3D FPS AI, into a simple statistical framework. Even biologically-inspired AIs like neural networks are designed to solve highly constrained problems. In short, I don't think it's possible to even design a non-bruteforce AI, regardless of computational power, with what we currently know.

The single biggest (and maybe the only) difference between Game AI and Traditional AI is the optimisation function. TAI optimises for correctness, followed by efficiency, and GAI optimises for efficiency, followed by fun. The inapplicability of TAI solutions to GAI problems is because we (the games industry) don't have any kind of theoretical framework for even measuring fun, let alone optimising for it.<p>The state of the art is essentially a handful of ad-hoc models of how people experience games, how they improve and how they have fun (and why they stop having fun). Coupled with that, you have an enormous range of player skill - the lead designer of World of Warcraft estimated that the capability of player groups varied over several orders of magnitude (and he's a former academic professor, so probably speaking literally).<p>Someone in another reply stated that GAI was roughly passing a restricted Turing Test. That seems like a reasonable suggestion to make, but if it's true, then applying TAI frameworks to solve GAI issues is roughly the same difficulty as trying to create a non-Turing-test passing AI that can write a Turing-test-passing AI. It seems intractably difficult with the tools that we have available to us right now.

It's a lot more important for AI for game characters to <i>look</i> real than to <i>be</i> real. It's easy to forget that the characters are there to support the fun of the game, and not to be fun to write or support the ego of the author. Incidentally, I thought the article was worth it for the mention of Infinite Mario and Galactic Arms Race alone-- I had not heard of those projects before.

A nice article, but I believe it should be mentioned that the main difference of game AIs vs traditional ones is, that the game mechanics are known. This means for machine learning algorithms there are a lot of low hanging fruits like perfect shooting (or more generally exploiting that a AI can usually control the game better than a human since it does not need to use a interface device). And because of this, it is actually necessary to tweak the AI such that the player does not feel cheated himself.

In single player games you have NPCs (non-player characters) and in multiplayer games you have bots (again, computer controlled characters). For instance, Team Fortress 2 has bots and Half-Life 2 has NPCs.<p>The difference is, bots behave and mimic actual human beings. They are bound by the same rules, and have the same controls and range of motion as human players. It's hard to distinguish the difference at times, granted they're far from perfect.<p>NPCs on the other hand, seem to be this "dumb" AI the article is referencing. They are intentionally made this way to serve a simple, singular purpose. They are either scripted for dialogue or just peppered throughout the map as meat puppets.<p>Why is it that we aren't seeing the bot approach to AI implanted into single player games? Why aren't we facing opponents who have their own missions/agendas in single player games, who are bound to the same controls/restrictions/exploits as yourself?<p>The current AI approach is to place enemies in hiding positions who want nothing more than to fight you to the death, without any purpose or reason.<p>I want AI that wants to do something, like another player would, that isn't concerned with me in particular, that has it's own goals/rewards instead of just fighting me or spouting dialogue at me.

The last in the office job I had (12+ years ago in San Diego, before my wife and I moved to the mountains in Central Arizona) was doing game AI for Nintendo and Disney.<p>I loved it! The only reason I left was that we bought a house and had been planning to move.<p>I only work remotely now but if anyone ever wants a technical partner for doing a small Indy game, contact me. I have no skills as an artist. I write code.

I've just had my first course in AI, and being interested in games, I was curious to see how the reasonably specific, theoretical techniques we were taught could fit into game design. This was a reasonably interesting example, but I think I'd be more interested in some specific applications, although I appreciate these might be jealously guarded secrets...

Yikes, so I've just stumbled across this and a couple of points to note: Firstly I wrote it over a year ago, secondly, I've written an awful lot more about it since then. In particular check out my most recent article - <a href="http://www.altdevblogaday.com/2012/08/27/the-spector-of-game-ai/" rel="nofollow">http://www.altdevblogaday.com/2012/08/27/the-spector-of-game...</a> and the video of my session from Casual Connect Seattle a couple of months ago - <a href="http://casualconnect.org/lectures/2012-igda-lectures/skynet-and-you-game-ai-for-the-uninitiated-luke-dicken/" rel="nofollow">http://casualconnect.org/lectures/2012-igda-lectures/skynet-...</a>

Good article.<p>Voltaire wrote something about this: "The perfect is the enemy of the good." It's hard to keep in mind, especially when inexperienced.

When it comes to game AI, mostly it is not about being smart or real. It is about being fun.

Eh, I don't know. I think that game AI just has to pretend to be real AI.<p><a href="http://www.gamespy.com/pc/fear/698080p1.html" rel="nofollow">http://www.gamespy.com/pc/fear/698080p1.html</a>