Ideas for a killer AI

[Dominae]

alexman, very nice effort. I have a couple of minor comments/questions:

Originally posted by alexman
From plugging the above values into the actual tech tree, it quickly became apparent that it's almost impossible to balance the AI choices using only the technology costs. For example, there is no way the AI will not research Bronze Working first (unless it already knows it).

So, what you're saying is that non-Scientific civs always research Bronze Working before any other tech?

Originally posted by alexman
Fortunately, there is another way. Writing gives special abilities like ROPs, Diplomats, Alliances, and Communications trading. If we attach any of these abilities (which are highly valued by the AI) to techs that come after Writing, there will be no difference in gameplay, but we can trick the AI into thinking that those thechs are more important than they really are! For example, we can make the AI research Literature or Republic much earlier than it does.

I like this idea. Very rarely are all the abilities Writing provides used right away, and I don't think I'd miss them too much in those cases where I may have a use for them. The sole exception to this would be Comm trading, which is so integral to the early-game that putting it anywhere but Writing would make things quite different. Here are my suggestions (although I haven't figured the new costs for the techs, so this may need to be tweaked):

Code of Laws: Rights of Passage
Philosophy: Alliances
Literature: Diplomats

I figure something should go to Polytheism to make the Monarchy path more attractive, but I can't figure what offhand.


Dominae

[alexman]

Originally posted by Dominae
So, what you're saying is that non-Scientific civs always research Bronze Working before any other tech?

Exactly, even if you increase its cost a thousand times!
Then they immediately research Warrior Code. After that, it depends more on the situation.

Very rarely are all the abilities Writing provides used right away, and I don't think I'd miss them too much in those cases where I may have a use for them.

I was actually proposing to leave Writing as it is, but give one or two of its abilities to Literature ALSO. Since you can't benefit from having the Diplomats ability twice, for example, gameplay would be the same (Writing is a prereq of Literature) but the AI doesn't know that, so it would go for Literature with a higher priority.

[DaveMcW]

Wow, great work!

But where are the random factors that allow 2 AIs to research down different paths and trade?

[Killerdaffy]

Originally posted by alexman
The AI places a value on each technology it can research next. The values depend on the various things allowed by each technology, as well as on the turns needed to complete the research. Here are the values:

Could you elaborate a little bit on your method for testing? How did you get the values?

[Dominae]

Originally posted by alexman
I was actually proposing to leave Writing as it is, but give one or two of its abilities to Literature ALSO. Since you can't benefit from having the Diplomats ability twice, for example, gameplay would be the same (Writing is a prereq of Literature) but the AI doesn't know that, so it would go for Literature with a higher priority.

Oh I see. I guess it was just wishful thinking on my part to "flesh out" the more useless techs with some abilities. Have you tested it out the way you proposed?


Dominae

[alexman]

DaveMcW, there might be a random factor, but I didn't find it with the method I was using to test. It's possible that the different research paths are entirely due to 1) different starting techs 2) Goody huts, 3) Unique units, or 4) different size ecomomies.

I made a big assumption to get these results. I assumed that the Science advisor suggests that the human player researches the technology that the AI would research under the same circumstances. There was no random factor whatsoever involved in the advisor, but it's possible that the AI players have such a factor.

KD, my tests involved stripping all techs of all benefits, and then slowly adding things and observing the preferences of the science advisor. Debug mode was very useful, as it allows you to gift yourself techs instantly, and the advisor then suggests a new one.

Dominae, I like the idea of "fleshing out" the tech tree too, and it could well be worth creating a mod that does this (the AU mod?), but this thread was simply for suggestions to improve the AI. BTW, yes, I have tested the AI value of already known abilities and it is the same as if they were unknown.

[Soren Johnson]

Originally posted by alexman
OK, I've been testing instead of playing again... but I believe I figured out the rules that the AI uses to choose the next technology to research. It took me many hours to figure this out, so bear with me!

very impressive work... however, if you discovered these values through tech trading, I should point out that it is not necessarily true that the AI uses the same priority system to determine which techs it decides to research.

[alexman]

I discovered these values by the suggestions of the science advisor. Please tell me that the AI uses the same advisor!!

Also, is there any random factor involved in the AI's decisions of what to research?

[Dominae]

It would be pretty funny if the human Science advisor and the AI Science advisor were different: "Yes, human player, you should research Amphibious Warfare (while we research Motorized Transportation)". Then again, the human advisor may be an aesthetic rather than strategic part of the game.


Dominae

[lockstep]

Originally posted by Dominae
I figure something should go to Polytheism to make the Monarchy path more attractive, but I can't figure what offhand.

Make the Hanging Gardens available with Polytheism instead of Monarchy.

(Actually, I already suggested this tweak for the AU mod some time ago because I wanted to reduce the number of 'empty' techs.)

[Dominae]

Originally posted by lockstep
Make the Hanging Gardens available with Polytheism instead of Monarchy.

Even if I didn't like it before (I don't remember), I like it now.

When are we going to "release" the next version of the AU mod? Some things about the standard game bother me quite a bit now (Archers upgrade to Guerillas!?!).


Dominae

[Catt]

Originally posted by alexman
OK, I've been testing instead of playing again... but I believe I figured out the rules that the AI uses to choose the next technology to research. It took me many hours to figure this out, so bear with me!

Wow! Great job, alexman!

I can't say I fully understand it, but think I've got the hang of it. Fantastic perserverance through what must have been lots of testing! Certainly sheds light on why the AI would rather be destroyed than trade Nationalism away.

Catt

[Theseus]

I forgot what a great thread this was... great job, alexman!

[fanes7]

Re: Ideas for a killer AI

Originally posted by alexman
In the thread titled "Why, oh why does the poor AI...", we identified some shortcomings of the AI in managing its cities. Until these issues are possibly addressed in a future patch, and in preparation for the PTW version of the AU mod, let us use this thread to agree on the best way to improve the AI using the current PTW editor.

[*]The AI doesn't build factories early enough. Even with "Production" as a build-often preference, the AI builds Factories after cultural buildings like Cathedrals and Research labs. Option 1: Mark "Production" as a build-often preference for all civs. Don't mark "Culture" as a build-often preference, since the AI already emphasizes culture over production. Option 2: Increase the maintenance cost for Factories and Plants. The AI does not consider maintenance in its build decisions. By increasing the maintenance of Factories, the AI will at least save some money from building them later.
[*]The AI builds too many units and not enough improvements. The real problem is that the AI NEEDS all these units because it's so bad in combat tactics. Option 1: Similar solution as with the Factories: increase the maintenance cost advanced buildings like banks, research labs, and cathedrals. The AI generally builds these later than the human, so we can save the AI some cash for doing so.


Any other ideas? Different solutions? Comments?
Sorry if you've seen all this before, I just wanted to get all these AI issues together somewhere.

This two things is the most poor point.

And I find another , AI can't deal with the war time well. In the war time , AI almost can't research any thing, especially when they lost a war .

Often, if AI is at your west , and if you declare war with the AI , then AI would not build city in your side.

And most other problem in the AI, such as , often you can't trade with AI with your gold per turn , but in a peace treat you always can use your gold-per-turn trade with AI . AI can't distinguish two things : 1. You lost and beg peace to AI , 2. You win and force peace to AI . So AI alway accept your per-turn-gold in peace treat.

Utilize the per-turn gold in peace treat , I always can get many things. Sometimes I didn't want peace at all , but for the AI 's tech or worker , I 'm very glad to use per-turn-gold to take a peace treat with AI and soon declare war again.

It is very complicated to manage the war time AI . Just an advice for designer&programmer . :-)