Most Impressive Game AI?

togelius asks: "I have the feeling that when developers make the effort to put really sophisticated AI into a game, gamers frequently just don't notice (see e.g. Forza). Conversely, games that are lauded for their fantastic AI are sometimes based on very simple algorithms (e.g. Halo 1). For someone who wants to apply AI to games, it is very interesting to know what AI is really appreciated. What is the most impressive game AI you have come across? Have you ever encountered a situation where it really felt like the computer-controlled opponents were really thinking?"

Comments

no

[flynt]

Have you ever encountered a situation where it really felt like the computer-controlled opponents were really thinking?

No, but I've rarely encountered games where it feels like my human opponents are really thinking, either.

Come off as cheap

[Romancer]

A lot of AI that is used in games today can come off as cheap since the computer can think and compare much faster than a human player. Imagine fighting an opponent that can react 10X faster than you.

Another way to look at it is if you think that the AI is learning patterns and adjusting for tactics.
That's been played out in many genres, the most recent to come to mind is the Stargate SG1 episode where a character must face a situation that adapts to his efforts and becomes impossible to beat since the game can react faster than he can and has a perfect memory.

It's a ballance that game AI must match, playability and difficulty.

Re:Come off as cheap

[mgiuca]

That's why the "best" game AI isn't necessarily the smartest or most responsive - it's the most human.

Writing an AI that makes the occasional "human error", or responds in a reasonable time is harder than writing the "best AI possible", but makes for a more believable (and of course, enjoyable (since who likes getting beaten all the time)) game experience.

Fact or fable?

[lawpoop]

When I was contemplating learning video game programming, I was reading a guide that told you first to program a pong clone, and then a pac-man clone. Why pac-man? It teaches you AI. The ghost behavior is actually fairly complex. One ghost wanders randomly, another tries to get on the opposite side of the board from wherever pac-man is. The other two form a hunting pair: one tries to cut off your escape while the other goes for the kill.

I never thought that the ghosts would be so complex!

Re:Fact or fable?

[EGSonikku]

And they aren't...at least not until Ms. Pacman. In the original Pac Man the Ghosts followed very predictable patterns which they never changed, and it is quite common to simply memorize these patterns and play the game with your eyes closed.

http://www.mameworld.net/pacman/patterns.html

Re:Fact or fable?

[FuriousBalancing]

Clever girl.

Re:Fact or fable?

[Threni]

To be fair, the fact that patterns work simply means the AI is deterministic. Pacman could have extremely complicated AI but if there's no learning from a players past, random elements etc you're always going to be able to learn to find a patten which works.

To be honest, I've always thought that AI in computer games sucked. Games are usually made hard by having the bad guys have better fire power, shields, energy etc than you, or having loads of them against one player. It would have been a laugh, for example, to have a doom style game with one player against one computer bad guy, but have him be as smart as a human. Thankfully, online multiplayer games mean you are no longer restricted to whatever crap AI system the programmers manage to string together, although the problem has now shifted to dealing with people cheat - a problem which games programmers show no signs of being any less inept at dealing with than with AI.

Re:Fact or fable?

[lawpoop]

This post seems to contradict your information:

"AI : We wanted to integrate in our game the original AI behavior of the ghosts (those that were in the original Pacman game). Without AI, the game was not interesting to play, since a random behavior is too simple to play. Each ghost has its own personality: Shadow is the red ghost and it chases Pacman all the time, using a straight forward tracking algorithm. Speedy is the pink ghost. It is very fast but moves in a random manner. Bashful is the blue ghost: it is shy at the beginning and escapes from pacman all the time, but if Pacman approaches him to much, then it is not shy anymore and begins to chase him (Pacman is then chased by two ghosts at the same time...). Pokey is the orange ghost and is slow and moves in a random manner. "

Not as complex as the story that I read, but apparently they don't follow a pre-planned course.

Civilization III

[Brandybuck]

Civilization III. It's uncanny how it makes you think the game is outright cheating.

Re:Civilization III

[Pyrrhic Diarrhea]

That's because it *is* cheating. The hole in my wall next to my computer can attest to this well established fact. :)

Galactic Civilizations 2

[Zarhan]

Well, one of the greatest experiences (And still is), AI wise, is Stardocks XXXX-type space strategy game, Galactic Civilizations 2. I especially like, when on easier levels, you do something, and the AI race sends a message "It seems that you are making a massive buildup for war. However, with this difficulty level, I pretend not no notice it until you actually make your strike." or something to that effect.

Counter-Strike AI

[Foo2rama]

I am constantly amazed at how bad the AI is in this game, after years and years of developement you would think that the Ai would have developed alittle more. While very advanced in speech capabilities, the AI relies on taunting you by claiming you are a noob, cheater, or a camping f**ktard, and will even call you GAY. In game play the AI is still weak and just does the same thing over and over again, and will constantly be baited into sticking its head around a corner, or runs into flashbang grenades on a very regular basis, failing to learn from its past and how it got owned over and over. Finally the AI deems you are a cheater and runs to load another AI called an Admin that will ban you because it cannot understand how you are so much better then it.

Friendly AI

[nmb3000]

Personally, while enemy AI is something that's pretty neat to see in action, it's the friendly AI that gets my attention. Most games seem to put all their effort into the enemy, while you friends turn out to be schizophrenics with an IQ of about 40. I haven't played, but I have heard that something that people complained about in Gears of War was was the poor team AI.

I don't play many games any more, but Halo 2 was one that I thought pulled ahead of the pack a bit. Friends that can drive vehicles was pretty cool (albeit not always the safest drivers...) allowing you to man the gun in the back. They also seem better at not running right in front of you when you're in the middle of launching a rocket, and also do little things like take advantage of available cover (or in other cases jumping up on top of said cover and getting blown to bits). Halo 3 is supposed to have even better AI for both friendlies and enemies, and that's one of the things about it I'm looking forward to.

Cheating

[dunezone]

Ive noticed that AI is not designed to beat your next move but is designed to cheat you without the player noticing. Command and Conquer and Gears of War are two games that have two well hidden cheats. Command and Conquer is twelve years old almost, the enemy AI was programmed to always have full resources as long as one harvester made it back. Therefor what would take you five harvesters would only require them one. Most players would of never noticed this unless their strategy was to cut off enemy resources instead of an full out assault. Gears of War was praised for having AI that used the environment to their advantage which helped cover a little cheat they had. The AI had a weird tendency to know exactly where you were as long as your cross hair covered them or came close to them. For example if you were to pop your head out and just happen to have your cross hair on an enemy turret that was always firing at a covered friend, it would immediately start firing at you, this would also goes for the regular grunts/guards. This is very noticeable on "Insane", since that mode requires you to use cover 90% of the time and better tactics then rush in and shoot everything that moves. AI is not designed to outsmart/out think/or consider your next move, in my opinion most AI is designed to defeat you by using small cheats in the programming that give it an unfair advantage and hopefully designed so that you wont be able to notice it.

Good, or good for the price?

[Pode]

GalCiv II has given me the worst beatings I've ever taken in a strategy game. Shogun: Total War managed to spring a tactical ambush on me once (although in fairness my grip on tactics was much worse back then). Both of those AIs gave me a challenging game experience as a player, which is what "good" AI should be judged by.
However, if we're talking about "impressive" AI, nothing I've seen in the gaming world can compete with Paradox's EUIII. Yeah, I know, each individual AI nation makes a lot of bonheaded moves. But the game is managing the armies, navies, economic, religious, colonial and foreign policies of up to 300 nations, every game day when a game year can go by in a minute or two, on a 1.9GHz processor. Considering the number of cycles and the amount of memory avaiable for each AI opponent, it's simply amazing to me. I really think that should be the basis of comparison, not so much the level of play the AI achieves, but the level of play it achieves with the resources available to each AI player. If nothing else, that standard makes it meaningful to compare old games against new ones.

F.E.A.R

[alphaseven]

Here's a short article on the A.I. in the game F.E.A.R., "F.E.A.R.'s AI Demystified", (in more detail here). Having played through F.E.A.R., what impressed me so much was that a lot of what is called A.I. is actually audio and animation. You can make enemies seem way more intelligent than they really are by doing stuff like have detailed animations for stuff like hopping over barriers or diving through windows that's triggered when they are in certain spots. They would also have the enemies shout stuff, if you had your flashlight on they would scream "Flashlight" and dive for cover.

Re:ummm, Galactic Civilizations II?

[PresidentEnder]

Galciv 2 certainly gets a huge vote from me, because the AI did beat the crap out of me, repeatedly. However, the AI does have the advantage of being able to accurately micromanage every planet every turn to produce the best combination of production, research, and cashflow.

I'm also very impressed with the AI in the original galactic civilizations. It does cheat at the higher levels, but up until that point (I think normal mode doesn't cheat either way) it's very impressive and it really does feel like the AI is thinking. More impressive is the fact that each major race has its own AI: not customized by arguments in the race, but specific, independent C++ code telling them what to do, written from scratch.

Screw game AI

[SharpFang]

Google Maps AI rules.
See point 23

Re:Simplfy the game and the AI gets better

[pescadero]

The important think to know about AI in games is it's not "AI". It's scripts or code that simulates scripts. There's no neural nets or anything else because we can't get the power for a neural net in an active game. In chess we can but then chess no longer is fun unless we tone down the "intellegence".

Hmmm. If I write a neural net program, how is that different than what you call "scripts or code"? It's still just code.

And the best chess algorithms (which you seem to claim are "real AI") are just search algorithms that search 30 moves into the future (with pruning)

You're making a distinction between "real AI" and "not real AI", when really there is no distinction. If a system can solve a problem intelligently then it's AI, regardless of the algorithm.

There *is* a distinction between "human-like AI" (neural nets) and other kinds of AI, but we'd be foolish to assume that human-like intelligence is the only kind of intelligence.

Re:ummm, Galactic Civilizations II?

[Edmund Blackadder]

I agree, GalCiv II certainly has a very tough AI.

Another very good one is freeciv. Freeciv may look much cheesier than the regular civilizations but in AI it surpasses it by far. I suppose it helps that it is developed by players of the game.

Game where computer seems like it is thinking

[Brian_Ellenberger]

Galactic Civilization I and II (see: http://www.galciv2.com/) is one of the few games I have ever played where it seemed like the computer was thinking. If you have never played GalCiv, and you like strategy, I highly recommend picking them up. I consider them to be superior even to the Civilization series. Brad Wardell prides himself on the AI, and it definitely shows. The computer is very difficult to beat and does not cheat. It actually responds in a logical manner, which makes GalCiv go from just being a number-crunching exercise to an actual strategy game. For example, when making some "aggressive" moves towards an enemy (moving some attack ships to an "ally" to wipe them out) I've actually had the game pop up a message from my ally (before ever entering his space) saying something to the effect of "I used to play video games when I was a kid, and when I did I used to build my forces up and send them to sneak attack an opponent. Well I am no video game." Other things like the fact that if another civilization is dependent on you for a large amount of trade income, they won't just randomly attack you because it would hurt them too.

Re:Game where computer seems like it is thinking

[Tablizer]

Other things like the fact that if another civilization is dependent on you for a large amount of trade income, they won't just randomly attack you because it would hurt them too.

That AI is smarter than most Earth leaders.

Re:Game where computer seems like it is thinking

[Kingrames]

90% of the time when it seems like the computer is smart, it's more because the game and the AI merge well together.

If the game has lots of bugs, bugs you might not normally see, the AI will suffer.

Oftentimes the A.I. of the game doesn't make the computer smarter. Making a game that's smooth and supports a good A.I., however, will make a much bigger difference.

With a game like chess, the A.I. program is huge and immensely sophisticated.
With a game like tic-tac-toe, you can make an A.I. that can't be beaten, simply because the game is simple and allows for that.

It's important to keep in mind that the actual A.I. algorithm can only accomplish so much. Putting Deep Blue into the seat of your tic-tac-toe opponent gives you the same result as the program you wrote that doesn't break a page.

That being said, a few more examples to look for for good A.I. that merges well with its game would be Kohan and Kohan 2. The AI in that game blew me away.

For an older game, check out emperor of the fading suns (you can get the full game for free) http://free-game-downloads.mosw.com/abandonware/pc /strategy_games/games_e_f/emperor_of_the_fading_su ns.html
I still have fun playing this one. It's interesting how the computer will actually send you money for nothing in the interest of making you like them more. There are a few other subtle details.

Incidentally I've heard that Gal Civ is based off of EFS, so if you haven't had a chance to check it out, enjoy.

Re:Simplfy the game and the AI gets better

[kinglink]

If we are talking about a computer game I'm hoping we are talking about human-like intelligence.

What I really was trying to get across was a common misconception (one that stuck me when I got into a game company) that "AI" as it's taught in school is very different hen AI as it applies to most games. The biggest difference is most AIs don't learn, and most are pretty much just a script that doesn't change. We don't have the ability to throw away any cycles of the game so the AI tends to be highly stripped down to the point it's just "oh I see a gun, I'm going to react to the gun, how should I react to the gun, I'll do that." This is completely scripted to the point where you can tell what's going to happen if you point the gun at the person a second time or a third time. There's no "thought" or "intelligence" to the system, thought it might seem "intelligent"

A chess AI on the other hand evaluates all the options of what it can do and chooses a best option, the pruning is a form of "thought". A chess master will be doing something similar where he thinks of all his possible moves and then considers responses and so on which is effectively using game theory. To me that's actual intelligence even if it's not fancy.

The difference between a neural net program is it's code that tries to simulate the learning and thought process if you will, the code that AI in games use is just like I illustrated above. There's an "action" and the code quickly decides what's the reaction and does it. It doesn't try to evaluate too much because we don't have the cycles to do that.

The original

[Squalish]

Unreal Tournament.

It had the first bots that you could play against for hours and not even notice you were offline. I havn't encountered a more convincingly human AI in the dozen FPS games I've played since, including UT 2k3(which probably means that the UT maps were just easier to code for).

It's the only game where you can feel yourself increasing in skill over the course of a few days of playtime, and ratchet up the difficulty a bit and get the same kill ratio, without feeling suddenly overwhelmed by perfectly aimed headshots.

I know the best AI ever!

[guruevi]

It's my manager's; Basically his algorithm is to listen to what I have to say, deny my ideas or find a situation where an exception would be generated and then depending on the number and level of participants, introduce my idea as his. I tell you, that shows great intelligence to his overlords although it's artificially generated but the actual participants start to get it after a few times.

Best game AI?

[TheCreeep]

Ask Kasparov...

Re:ummm, Galactic Civilizations II?

[ditoa]

I just went to the GalCiv2 website to have a read and saw this

No CD copy protection. Once you install, you never need your CD again. You can even use the included serial # to re-download the entire game from us years from now.

That is very refreshing to see these days. I have given up on most PC games these days because of their copy protection systems.

Re:ummm, Galactic Civilizations II?

[Anonymous Coward]

I don't know where you're getting that bullshit from, but it's completely untrue. You don't even have to enter the CD key unless you want to download updates.

The Thief Series was Groundbreaking

[BrendaEM]

The AI could see not only see in a view fustrum, but also by how much light you were lit by. The AI could hear depending on what surface you walked on, you could affect the light by putting out torches, affect the sound my mossing the floor. The AI notice bodies and things out of place, such as a climbing rope. The AI also had different alert states. I think that they are pretty good for a game made almost a decade ago.

There are over 400 Thief series fan missions. Last night, I played "Ominous Bequest"
http://southquarter.com/?p=131
One level change for 6 hours of gameplay! Yes, Thief 1 and 2 graphics are quite dated, and low-poly, but if you can forgive that, the gameplay and atmosphere compensates for it.

Lately, there's been a reinsurance in Thief 1 and 2 add-on missions. There's a updated version of 680mb Thief2X add on. Missions like "Ashen Age," and a "Night in Rocksburg" have breathed a little life into T2 visually.
http://forums.eidosgames.com/showthread.php?t=5526 3
http://southquarter.com/?p=131

Someone is working to refresh the Thief Series Engine, but the source code would help. I wish that Eidos would release the source code--for an eight year old game.
http://www.ttlg.com/forums/showthread.php?t=102289 &page=11

Far Cry

[lewp]

Far Cry has great AI. I don't remember ever going "zomfg the computar is thinking!!!", but the enemies respond in a sensible, coordinated manner -- sweeping areas where disturbances are heard, covering each other, and using weapons intelligently. Far superior to Half-Life (and, credit where credit is due, several years after Half-Life), but also in a much more open-ended game world, where the mobs don't just have to navigate a room full of crates.

The really sad part was when, halfway through the game, they switched from "smart" soldiers, to Doom-esque mutants who just ran straight at you. Ruined that game for me.