{The List} AI

[MrBaggins]

Again goal-oriented models like this are great to consider, until you get to the point of valuation.

Its simple for an instant... within a certain turn, but when you start introducing time, and evolving situational data into the equation, you start getting problems. Its tricky to assign a value to whether you should build an army and attack to get, say 2 towns, or more beneficial to delay and build up your own cities.

This leads to a whole host of problems including determining reasonable target goals (with infinite possible goals, whats a reasonable army size to aim for and what are reasonable conquest/defense goals, for instance), solving indescision (illustrated in the quoted passage below) and understanding when and how to abort a goal.

"The Civ3 siege model builds an attack stack and sends it to rout a city. The weaker city. A player can cause it to keep changing its mind by ferrying."

Having said that... the concept of victory/strategic/tactical hierachy is probably the best "real" solution. No current AI designs "out there" have solved these issues. I know Clash is going this route, but is better structured this way. Its not solved all these issues yet, either, however.

Civ "decision space" is just to monumental to be able to "solve", completely.

So whats happening at the moment is more and more sophisticated heuristic designs.

CtP1 was interesting in its use of a fuzzy design. It however, used the fuzzy system with largely binary choices, and by all accounts, bad defuzzification, making it essentially heuristic, even if you could extend it yourself.

[ixnay]

Give the AI the ability to recognize if events leading to deals with them getting canceled were out of your control or deliberately player-caused.

I'm tired of trading with one computer civ only to have some crazy war break out somewhere that disrupts my trade route with them. After this no other civs will trade with me; they're all "RAR WE REMEMBER WHAT YOU DID TO FRANCE WE'RE NOT DUMB SO WE'LL NEVER TRADE WITH YOU"

[Nikolai]

List updated!

POTUS: If you can beat Deity, you're NOT the worst Civ player ever, I can assure you!

[Jamski]

Diplomacy AI :

I want the AI to ALWAYS be open to talks, even directly after a DoW. Of course the AI should accept peace if there's been no actual fighting, or if its clearly losing. If the AI declares war, you should be able to contact it straight away and ask "what do you want to call off your dogs?" Those times where the AI DoWs you out the blue and won't even talk until x cities have changed hands really makes me MAD!

If the AI is under attack by another AI, it should contact all civs, including the player, and ask for help. Depending on situation it could ask for trade embargo, cash, alliance etc.

If the AI wants to move through your territory all the time it should also want to PAY for a RoP agreement. As it is, it keeps wandering through, and then wants you to pay THEM for the RoP.

Before declaring war the AI should always make a final demand.
"Give me Athens/Gunpowder/Furs or I WILL declare war"
You should be able to make a counter-offer
"How about instead of Athens I pay you 8gtp?"
Then the AI says, "hmm... offer a bit more and I'll leave you in peace"

World-war triggering. The AI embarks on a world war if it "feels strong enough" (more than 25% of the worlds forces or something, adjusted by number of civs alive at the time) and attempts to take on everyone. It contacts all civs with the offer,
"Pay huge sum/cities/tech or join me in war against xyz, or I DoW you."
This results in either a killer AI, or at least a huge war with multiple civs on each side.

Restrict tech trading : Neither you or the AI can trade a tech in the turn you get it. This cuts down on tech whoring AND the "feature" if you trade a tech to the AI in its turn, it then trades it to all the other civs immediatly. Should slow the tech rate marginally.

New agreement : research pact. You and the AI civ agree to share all your research. If one civ has a better research rate, then the agreement is "worth more" to the one with the lesser tech rate, and they may offer additional trades (luxuries, money, troops)

New trade : UNITS! Make all units except UU's tradeable just like workers are now. Mercenary units from another civ cost double gold or something to support. The units appear in you capital.

New Agreement : Favored trade partner. This gives you +1 gold in each town connected to the AI's cities, +2 in each city and +3 in each metropolis. The AI gets the same benefits. You can only have one trade partner at a time. It make that AI like you more, and makes other AIs dislike you more. Breaking the agreement lowers your reputation with all civs EXCEPT if you break it by signing the agreement with another civ, who then think you are great.

-Jam

[Nikolai]

Lots of good ideas, Jam! I'm a bit unsure about the world war part though; the AI should be very sure on itself before it does something like that. And if it's implemented, it's important that the other AI's have some way to consider if the threat is big enought.(especially if the player and the AI has good relations)

*Updated*

[Jamski]

Yeah, the AI would need 55% with 2 civs, 40% with 3 civs, 30% with 4 civs, 26% with 5 civs, 24% with 6 civs etc...

-Jam

[Shogun Gunner]

Actually I like the world war option -- if it works right. If this messes up the computer's logic, which can be shaky at best, then this feature would be a disaster. I'm thinking never ending conflict between civs....

Now that I'm typing that a battle to the death doesn't seem so bad...

[Trifna]

Perhaps that to consider a multi-threaded AI like in GalCiv would be a good idea. It apparently got good results for GalCiv, but I don't know technicals alot to say it's also good for Civ4. In the case of GalCiv, it permits an overall better AI.

Someone knows?


PS: I hardly know what a multi-threaded AI is technically, but it's one of the unique elements of GalCiv, helping the AI (which was praised by many).

[Fosse]

"multi threaded" just means that the AI is "thinking" while you are taking your turn.

It makes a huge difference, and should DEFINATLY be done.

[wrylachlan]

Make the AI think in terms of "Fronts". So if its at war on three fronts, it first analyzes each position, says "I'm good here" or "Little help please" and the AI then distributes reinforcements, but the battle strategy is figured out on an individual front basis. This allows the AI to work much faster because the scope of its calculations is narrower.

[7EA]

"multi threaded" just means that the AI is "thinking" while you are taking your turn.

Does that mean that if I finish my turn fast the AI will make more stupid moves?

[Trifna]

One thing: the AI should NOT move its units all over the place for no reason. It's really completely silly to see the AI constantly move its stuff for no reason...

Galactic Civilizations, I don't know why, don't have AIs that move their units all over the place during turns.

[Jamski]

Make the AI think in terms of "Fronts". So if its at war on three fronts, it first analyzes each position, says "I'm good here" or "Little help please" and the AI then distributes reinforcements, but the battle strategy is figured out on an individual front basis. This allows the AI to work much faster because the scope of its calculations is narrower.

This ruined the MoO3 AI. It tryed to spread its forces over many fronts, meaning it was never a real threat on any of them. The Ai should think TARGETS, not fronts. It should have a goal like : get Athens, and defend Rome with x troops. Simple.

-Jam

[Peter Triggs]

Does that mean that if I finish my turn fast the AI will make more stupid moves?

Depends how many keys you can press per millisecond. (joke/response: groan)

But seriously, GalCiv originally came out in 1993 and even then had AI multithreading:

One characteristic of the early GalCiv was multithreaded AI (a technology possible even in early versions of OS/2), and the newest incarnation makes good use of it as well. While most strategic games have to do a terrific amount of number crunching to run the AI after you press “next turn”, GalCiv is uniquely different: the AI is running all the time in separate ‘threads’ in the background. In fact, GalCiv has been hailed as the first computer game to use Intel’s new hyperthreading to good effect. (Note: you don’t need a hyperthreaded processor to run the game, but if it’s available the multithreaded AI will take advantage of it to run even faster.) When you hit “next turn” - even in the later game stages on huge galaxies where hundreds of ships and planets are all doing their thing - it processes quickly, even with the meager minimum / recommended system requirements.

Multithreading is not restricted to AI, it's basic stuff. I suspect that what's at least as important with regard to GalCiv's AI is that it probably uses different techniques. (I'm only going on what I've read on the Net.) Here's an old interview with Brad Wardell where he talks about AI:

http://www.geocities.com/TimesSquare/Realm/4330/iv_wardell1.html

And here's a later (long) one where he talks about GalCiv's development (and also mentions AI):

http://www.gamespy.com/articles/may03/galcivpostmortempc

edit: Update. Just got an e-mail from GameSpy who have named GalCiv as the PC turned based strategy game of the year:

http://www.gamespy.com/goty2003/pc/index13.shtml

[Fosse]

Originally posted by 7EA


Does that mean that if I finish my turn fast the AI will make more stupid moves?

Possibly, but what it should mean is that if you take long turns then the AIs will already be finished, and have made better moves than with standard Civ-type AI. If you take short ones, you'd have to wait a little longer.

What it could mean is that the AI is able to be more complex, and make better decisions, without technically being faster, since it's thinking during the player turn.