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?"

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 [mameworld.net]

Re:Come off as cheap

[CastrTroy]

Games have gotten a lot better. I remember in the original Mortal Kombat, you could get to the dual-character matches simply by picking scorpion and pushing back,back,punch for the harpoon, followed by down+punch for uppercut continuously for the entire fight. Games have gotten a lot better at not letting you do the same thing over and over again. However, I have yet to find a hockey game that doesn't have a "trick" that lets you score about 30 points in a game. the trick seems to change from year to year, sometimes it's the wrap around, sometimes the one-timer, but there is always a trick.

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" [gamespy.com], (in more detail here [72.14.203.104]). 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.

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.

Re:Fact or fable?

[lawpoop]

This post [stanford.edu] 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.

Battle for Wesnoth

[Anonymous Coward]

http://www.wesnoth.org/ [wesnoth.org]

Re:Simplfy the game and the AI gets better

[daffmeister]

Actually chess masters don't evaluate every move and every counter move in the manner that a computer program does. A lot of their analysis is based on familiar patterns, recognising promising lines by this method.

Witness Kramnik's missing of a mate-in-one in the recent match against Deep Fritz. It was such an unusual pattern (opposing knight on the eighth rank) that he just completely missed it.

Chess programs are much more about brute force. They've got so good at brute force that it looks pretty intelligent now.

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.

Re:ummm, Galactic Civilizations II?

[Anonymous Coward]

Odd. The copy that I downloaded and installed let me take those installation files, copy them to another computer and install it there. I then loaded Stardock Central on another computer and installed GalCiv 2 there while I was downloading updates on my computer. In fact Stardock explicitly allows you to install on multiple computers as long as you agree not to play on more computers at once than you've bought copies for. So my stepson can play after school on our kids' computer while I'm at work, then I can play on my computer while he's at his dad's.

S.T.A.L.K.E.R

[Eesu]

Been watching it for 3 years at least, originally its AI was going to be groundbreaking. After getting the game last week, and playing/beating it, the AI was indeed SUPERB, but not groundbreaking. However It is the best AI that I've ever faced. As a group of enemies slowly move from covered position to covered position and outflank me to get a shot, always keeping their heads JUST above say the ridge of a hill to give me the smallest target possible, ducking back behind cover to reload, crouching and walking slowly when trying to be sneaky. It was truly outstanding AI and I Appreciated the hell out of it.

Re:F.E.A.R.

[PeolesDru]

I agree. I remember the first time I played the F.E.A.R. demo. I was coming out of Doom 3, where I had gotten used to the old "get the enemy's attention, back up around a corner, wait for zombies to blindly follow you, pop their heads off with a shotgun" formula. I remember being very impressed with the fact that when I tried that after happening upon some guys in a room (I backed out) I found myself waiting, and waiting for them to follow - but they didn't! I peeked back in and they were nowhere to be seen - they'd actually taken cover! After the firefight started, one of the guys actually jumped out a window and rolled into cover behind a crate.

So I got the game itself and found the A.I. to be just as good. Best FPS A.I. I've seen yet - hands down.

Re:Actually, I really hate this

[vux984]

There was a game, Warzone 2100, that was absolutely brilliant in this regard. Not because the AI didn't do this, but because the player COULD. Not to the same level as the AI, but enough to give one an awesome sense of power over the battles.

Key features in that game:

Ctrl-click/double-click/box selection, and assignment of keyboard shortcuts (stuff we're familiar with in all games)

The ability to set postures like do or die, retreat at half damage, retreat at 3/4 damage etc (again familiar stuff)

Repair facilities - buildings that would repair nearby units - but with a twist. Vehicles set to retreat at X damage would retreat to the nearest repair facility instead of just going back to base and sitting there.

Mobile repair vehicles that automatically sought out and repaired nearby damaged units

Build Order chaining - you could give your construction vehicles orders to build a barracks, then a missile silo, then a factory, then a wall.

Target chaining. You could give a battle group a series of targets that it would attack. Commonly in these games we want to concentrate firepower, and this makes that happen.

Battle field production - you can actually order new units be produced at any of your factories anywhere from the front lines.

Target designation units for airstrikes, and artillery bombardment, as well as 'counter target designation units'. For example, you can assign your aircraft to a designator tank unit. Then whatever that tank targets becomes the target of all the aircraft assigned to it. They'll fly in, fire off their munitions, return to base to refuel/reload, and then fly back...

Or, for example, if you have a counter designator in an area taking artillery fire, the artillery guns in your base will automatically fire back on the source of that fire, if they're in range. (and those guns have AMAZING range.)

General units - this is the ultimate innovation. These units form the focal point of your armies.

Generals are hard very tough to kill units with a long range targeting laser. They have dedicated gui features to select and cycle between them. Units assigned to the general go where the general goes. Whatever they paint the units assigned to them attack. So...

Naturally you can link units to your generals.

You can move a diverse battle group without having to setup keyboard shortcuts, box selection, etc. This comes in handy, because it frees your keyboard shortcuts for other tasks. And units don't get left behind.

You can order that diverse battle group to attack a target, or series of targets.

You can link factory production directly to generals. (And built units automatically join the battle group.)

If the battlegroup is set to retreat at half damage, damaged units automatically return to the repair facility, and upon being repaired, rejoin the battle group.

The power this gives you is sublime, you can actually effectively fight on 2 fronts while holding down base defenses or doing mop-up. In most RTSes as the battle progresses you'll start to wear your battlegroup out, production will languish, units will be left behind, and evenually you have to call off the attack, order/pickup new units, and re-organize for another push.

With Warzone 2100, you can order up replacements for your losses as they occur without leaving the front line, you group will self repair, and repaired units will automatically return to the battlegroup. That combined with target chaining, and other features allows you to leave a battle for a few seconds to focus on something else (e.g. switch between multiple fronts or handle some base construction) secure that your armie can take care of itself for a minute on its, and worst case will be forced to retreat.

The only real concerns is if you are completely outclassed and can't even survive retreating, or if your supply/resupply pathing gets intercepted (or the AI chooses to send your damaged units into the enemy to get to the nearest repair center).