22
Feb
09

That’d be nice; Better A.I.

Yes games have come a long way since the days of games composed of whiney static on tapes, and the main protagonist was composed of 4 pixels. We’ve come leaps and bounds since the games industry’s second revival in 1985, I still remember being mind boggled by the graphics of Desert Strike. Graphics have gone from two dimensional sprites in a world of tiled textures to a fully three dimensional rendered world of bloom and lighting effects. Audio has transcended from simple blips and beeps your computer made to dramatic music and delicious ambient background sounds. Stories have gone from saving the princess to epic tales that take multiple games to tell. And now even real world physics are being put into games, soon the games developers will need at least one physicist on the team.

While those have come many miles since their first incarnation, the A.I.’s progress seems to have all the progress of Sisyphus pushing his boulder up a mountain. Sure A.I. now is far superior than that of yesteryear but it’s progress doesn’t seem to be as important to game developers. Everytime a developer raves of their A.I. improvements it turns out to be little else than a more refined version of the marines from Half Life. Of course this is an unfair generalisation, but it still seems that the dream of facing off against A.I. that could actually challenge you (without cheating, i.e. catch up A.I., see mario kart and nearly every racing game) has been lost in favour of online play. Only RTS games seem to really get a clever A.I. (Galactic Civilization 2)while us dumb FPS gamers are stuck with A.I. that still sometimes run straight off cliffs or into fire. So I have devised a shopping list of things I would like to see used more in games.

Line of Sight

How many times have I played against an all knowing A.I. that seems to always know where I am, even if I booked myself a flight half way across the world they will still know and head straight there. How many times have I been playing around firing my shotgun and tossing grenades for yucks only to round the corner and see enemies completely oblivious to my noisy antics. I’ve seen far too many A.I. enemies all with x-ray vision and lack of hearing.

I would love to have the ability to actually lose my opponents, without having to specifically play a stealth game. I want to be able to be a coward and hide in a room only to hear the A.I. give chase and slowly check each room. To be able to take a high perch and pick off the enemy with a sniper rifle without them instantly knowing my exact position after the first shot. We had this A.I. back in the first Metal Gear Solid game, so why not implement it into other games.

Retreat!

I would love to see enemies that can actually fully retreat instead of getting part way and then charging right back at me. I can better explain this problem with a short story about playing Second Sight:

At the start of the game you must escape a laboratory, as soon as you exit your room a pair of guards that spot you. Now at this point you can use you telepathic powers to scare the guards. It was great fun to see the guards run away into the corner and go fetal, shivering in fear as I floated the bin above their head. But just as I was being impressed and immersing myself into this game the guard suddenly bolted upright and continued his assault on me. I picked up the bin again and he fled to the corner, but once again after a set time would completely forget the fact I can make things float and charge at me again. My immersion was lost.

OK so you may be saying, “but that’s an old game we’ve come along way since then,” but really have we? It may not as apparant any more but the A.I. will still fling themselves at us with no fear even after we’ve slaughtered their whole team before their eyes. What I would like to see is the A.I. say, “bugger this,” and retreat further into the level to meet up with their comrades, meaning a few more to fight in a later encounter. Or once you’ve decimated most of their co-workers they can make a fighting retreat into a spot they can secure more easily, to retreat to a place where they have the advantage. Or my personal favourite make the last survivor either go fetal, or run away never to be seen again.

Stalkers

This would be a great special enemy for a horror game, although it could be used for others. This enemy will be armed with nothing but a simple melee weapon, and unlike most enemies it won’t blindly attack you from the front. The Stalker would do as the title indicates,it will stalk you. The Stalker will follow you from the shadows and strike at the most opportune moment, the Stalker could follow you around for most of the map just waiting for the right moment.

If you see his shadow peaking from a corner and go to investigate the Stalker will hide. If you think your being followed you can plant a proximity mine down, if the Stalker doesn’t spot it then boom, but if it does then it will set it off from a safe distance, which will let you know you are being followed and delay the Stalker. This would be very difficult to get right but damn when done right it’d be a hell of an enemy.

Conclusion

Of course A.I. is circumstantial to the enemy being coded, none of the above would work for coding a zombie, but I generalised to the atypical marine enemies. I know a complaint may be, “oh but coding that kind of stuff would be a complete nightmare,” and I say yes, yes it probably would be but if a coder isn’t dreaming of one day coding such an intellegent A.I. then they are doing their job wrong. A.I. improvements seem to be more tiny refinements on the last A.I. made rather than trying something new and exciting, games actually will work around poor A.I. with set pieces and scripted moments. I know this has barely scratched the surface of clever A.I. but it should give you an idea of what could be if developers spent more time on A.I.

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4 Responses to “That’d be nice; Better A.I.”


  1. February 23, 2009 at 4:09 am

    We hear you. The AI Game Programmers Guild is holding a 2-day AI Summit at GDC.

    While writing convincing and comprehensive AI is not as easy as it might seem, some of the things you are suggesting are readily doable. However, part of the problem is that designers don’t WANT some of the features you mention… often because they (I believe, mistakenly) insist that their players don’t want those features. “Who wants an AI that runs away when it is a fighting game?” It is posts like yours that help the cause. Keep telling us that you DO want challenging, immersive AI. If we can get game companies (and publishers) to budget for it and let us do our jobs, we are certainly ready to provide it to you!

    Dave Mark
    President of Intrinsic Algorithm LLC
    Co-founder of the AI Game Programmers Guild
    Co-organizer of the AI Summit at the Game Developers Conference
    Author of “Behavioral Mathematics for Game AI”

  2. March 2, 2009 at 5:08 pm

    I agree completely but with one minor quibble; game stories really haven’t improved, not if you actually think about them (see Shamus Young’s analysis of the story in Fable 2 as an example – and that’s an RPG which you would expect to have a strong story).

  3. 3 Idlehands
    March 9, 2009 at 2:00 am

    @Dave Mark
    Thank you, it’s good to know that people in the business also want better AI.

    @Recursion King
    Very true, the story telling in games hasn’t progressed much either but I guess I didn’t realise it because I’m used to the general mediocre story telling, which is not a good thing. I recently got round to playing Planescape: Torment and have been absolutely absorbed into the story. It’s not just the story but also how it’s conveyed across to the player.

    Plus thanks for the link I liked the article there. Here’s a link

    to an article about AI being implemented into games that I found interesting.

  4. March 9, 2009 at 12:11 pm

    Planescape torment is a huge exception and a very good story I have to agree. The only recent example of good story telling that I can think of is in Bioshock, which has a well developed and interesting setting and a few twists and turns along the way. By and large, story telling in games seems to be tacked on as an after thought – like some AI in games seems to be, too.


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