AU mod: AI build priorities

[alexman]

The AI build priorities don't always match the human build priorities. This is expected, as it is often necessary to compensate for the AI's poor military tactics. However, even taking into account the differences between AI and human optimal strategies, there are some areas where the AI build priorities could be improved:

• The AI uses its workers inefficiently and takes a long time to improve its land. The AI would clearly benefit from more workers.
• The AI does not use the luxury slider, so it runs into significant happiness problems, especially in large cities building Wonders. The AI would benefit from building more happiness improvements and Workers.
• The AI often misses trade opportunities because it delays building harbors, and even when it trades luxuries, it does not benefit from them as much as it could because it doesn't have enough marketplaces. Given the AI's happiness problems, it would clearly benefit from building more trade improvements.
• The AI often delays building factories, and as a result its Industrial Age production suffers. The AI would benefit from building production improvements.
• The AI often fails to take advantage of its traits. Scientific civilizations would benefit by building scientific buildings at a higher priority, Religious civilizations by building happiness improvements, Militaristic by building militaristic improvements and units, et cetera.
• The AI cities often grow too fast for their own good. Since the AI doesn't know how to set up Settler and Worker factories, and since it has happiness problems, the AI would benefit from building fewer growth buildings.
• The AI does not build enough air units, now that airpower has been strengthened in C3C. See the Balancing Airpower thread.

With the above in mind, it would appear that the 'build-often' items can be changed for each civilization, resulting in better AI build priorities.

• All civilizations should have Workers, Trade improvements, and Air units as build-often. This will encourage the AI to build Workers, Marketplaces, Harbors, and planes.
• All except Scientific civilizations should have happiness improvements as a build-often item. This will help the AI build Temples, Cathedrals, and Marketplaces.
• Scientific civilizations should have Cultural improvements as build-often, instead of Happiness improvements. This will help keep the number of priorities down. Scientific improvements have more culture than happiness improvements of the same level.
• Militaristic civilizations should have offensive units as a build-often item. Defensive units are already built often enough by the AI.
• Seafaring civilizations should have naval units as a build-often item, in order to take full advantage of the trait's benefits.
• Civilizations with 'builder traits' should have production as a build-often item. It's not that civilizations that need to build units do not need the extra production from factories, but keeping the number of build-often items low should make each build-oftem item more effective. Aggressive militaristic civilizations should usually not be building a Courthouse instead of another Swordsman.
• Growth improvements should be removed from all civilizations' build-often lists.

Another way of influencing build priorities appeared to be through the use of flavors. Unfortunately, flavors don't seem to influence the AI that way at all. Until we gain a better understanding of flavors, the AU mod will not use them to affect build priorities.

So what do you think? Does the above proposal for build-often items seem reasonable? Do you have any other ideas of how to help the AI in its build decisions?

[ducki]

Originally posted by alexman

• All except Scientific civilizations should have happiness improvements as a build-often item. This will help the AI build Temples, Cathedrals, and Marketplaces.

As long as this doesn't mean the AI is building Colosseums as a priority, I agree.

• Militaristic civilizations should have offensive units as a build-often item. Defensive units are already built often enough by the AI.

From the issue list prior to the suggestions, it sounded like Barracks would also be on this list. I'm not sure whether i think that's a good idea for a Mil civ. Yes, they're cheap and give vets, but with enough offensive units, they'll get plenty of vets anyway through faster promotion and the upkeep of build-often barracks may be worse than having more vets. If you omitted military-buildings purposely, ignore this.

• Seafaring civilizations should have naval units as a build-often item, in order to take full advantage of the trait's benefits.

I had a game with Byzantium as an AI and there were Dromons everywhere, sending settlers to god-knows-where, beating me to island settlements, and generally making me nervous. If Byzantium is the only civ that does this, and she does it with regularity, maybe there's something in her makeup that we can duplicate to other civs. If it's simply that the Dromon is the UU so gets build en masse, I wonder if there's a way to use that without having to add UU boats to every Seafaring civ.
Anyone else notice that Dromons move in packs and there's a boatload(ha!) of them normally or is it just me?

• Growth improvements should be removed from all civilizations' build-often lists.

Has anyone noticed if Soren's mining-irrigating-under-despotism fix from PtW made it into 1.15? If so, Granaries may actually be a good thing. If not, definitely do something to slow the AI growth under despotism.(Hmm... said that way, it doesn't sound so good, but oh well.)
(Edit: Is it possible that flagging workers and settlers as build-often with make this change extraneous? Probably not, but just a thought. If these two changes in conjunction fix the problem, we may not know which one did it. Maybe try the workers-settlers thing first and if it's not enough, tack this on later?)

So what do you think? Does the above proposal for build-often items seem reasonable? Do you have any other ideas of how to help the AI in its build decisions?

Thorough and well-thought-out as always alexman. I know it seems like I flog your ideas with regularity, but it's always in the spirit of improvement. Thanks for all the effort you put into AU past and present.
Good stuff, I can't wait to see what we come up with for the first version and the first game. I may even try emperor.
I'm giddy like a schoolgirl.

[alexman]

Thanks ducki.

Originally posted by ducki

As long as this doesn't mean the AI is building Colosseums as a priority, I agree.

Unfortunately, there is no way to tell the AI to build a Temple but not a Colosseum. Fortunately, Colosseums have already been improved in the AU mod.

From the issue list prior to the suggestions, it sounded like Barracks would also be on this list.

Actually, I'm not sure how to tell the AI to build barracks. When I mentioned militaristic buildings, I meant half-price harbors and airports.

I had a game with Byzantium as an AI and there were Dromons everywhere, sending settlers to god-knows-where, beating me to island settlements, and generally making me nervous.

I suspect the Byzantines are a special case, because the Dromon is a UU. However, they do also have Naval Units as a build-often. Did they continue to build naval units after Astronomy?

[donZappo]

I seem to recall reading somewhere (I believe the website of a top beta tester... can't recall his name) that the AI has gotten a lot better at building workers, although it likes to assimilate them into cities when its done with them and rebuild them all when need be. The argument was made that it would be a lot better if the AI just let the workers sit around until they were needed again as assimilating and rebuilding slows down the AIs ability to quickly complete worker jobs. What if we just removed the "join city" flag from workers? I wouldn't miss it, and it would help the AI if it still acts this way. Would it remove strategic choice from the player and be sorely missed? I don't know. This could be a highly used feature of the worker, but it was my impression that it was not.

-donZappo

[ducki]

@alexman - I abandoned that game with Byzantium for some reason and moved on. I might be able to dig up a save.

@donZappo - I'd miss the ability. One of the ways to mitigate the "you-have-enslaved-our-people" attitude hit is to join them to your cities. Also, if I'm lucky enough to have a steady stream of workers, I can boost my population in outlying towns a bit. I'm not sure I would say "sorely" missed, but I'm not too fond of the idea. I've only just learned of this feature's power.

[lockstep]

Originally posted by donZappo
What if we just removed the "join city" flag from workers? ... Would it remove strategic choice from the player and be sorely missed? I don't know.

If you want a fair chance to build key Wonders (not to rush or conquer them) at Monarch or Emperor, you need a high-shield city ASAP. For me, this normally means producing workers in outer cities only to add them to my soon-to-be wonder-city (usually my capital because of the minimal shield waste). Removing the 'join city' option means weakening one of the few viable buider strategies on higher levels.

[donZappo]

Yeah, strike that idea. That's what I get for posting when I first wake up in the morning! Heh...

-donZappo

[donZappo]

Originally posted by alexman
All except Scientific civilizations should have happiness improvements as a build-often item. This will help the AI build Temples, Cathedrals, and Marketplaces.

I like this idea. If you combine these buildings with double powered entertainers then it seems like the AI can be competitive against a human who utilizes the luxury slider. Both of these changes would seem to mesh well together.

Seafaring civilizations should have naval units as a build-often item, in order to take full advantage of the trait's benefits.

While this seems like a good idea on the surface, I'm always leery of any change that makes the AI build a lot more ships. Most of the time the AI benefits more from having a ground unit than having a sea unit and I wouldn't want to make seafaring civs easy targets for ground-based assaults. I'll pay more attention the next game I play to see if seafaring civs build enough boats as it is.

Civilizations with 'builder traits' should have production as a build-often item. It's not that civilizations that need to build units do not need the extra production from factories, but keeping the number of build-often items low should make each build-oftem item more effective. Aggressive militaristic civilizations should usually not be building a Courthouse instead of another Swordsman.

I'd be interested to see every single civ have this trait and see if it works. The benefits from this are universal, and if a civ didn't have another "build often" trait then its builder characteristics would just be emphasised.

Growth improvements should be removed from all civilizations' build-often lists.

Maybe agricultural civs could benefit from having this trait?

I know that the "build often" flag has been used in AU Mods in the past, so how do you long-time players feel that these added to AI competitiveness? Most notably, I think that the build often was flagged for workers and production... but I'm not sure. Did the AI in fact build more workers?

I like this idea a lot and would like to see it incorporated in some way in the mod.

-donZappo

[alexman]

Originally posted by donZappo
Maybe agricultural civs could benefit from having this trait?

I think Agricultural civs would actually be hurt the most by this trait. They already have a higher food surplus than other civs, so their happiness would become even worse.

I know that the "build often" flag has been used in AU Mods in the past, so how do you long-time players feel that these added to AI competitiveness?

Build-often flags have a smaller effect than you might imagine. A civ with happiness problems will always build a Temple over a Library, for example. It's only when none of the items are urgent, or both of them are urgent, that build-often comes into play.

Most notably, I think that the build often was flagged for workers and production... but I'm not sure. Did the AI in fact build more workers?

Workers have never been a build-often item in the AU mod. From a quick test, the flag didn't seem to affect the AI decisions. The AI likes to have one worker assigned to each city, and this comes after the unit requirements have been met, but before any city improvement decisions. All this is from limited tests though, so I might be wrong.

The production improvements were flagged as a build-often item from the very start. The effect is that the AI places a higher importance on factories, plants, and courthouses over other improvements. We could certainly use that flag for all civs, although that would mean at least 6 build-often flags for militaristic civs.

[alexman]

The following proposal is now under consideration:

  Civ Off Def Art Stl Wrk Nav Air Gth Prd Hap Sci Wlt Trd Epl Clt

  Rom  X   -           +       +   -   X   +           +
  Egy                  +       +   -   X               +       X
  Gre                  +   X   +               X       X       X
  Bab      -           +       +   -   +   +   x       +        
  Ger  X               +       +               X       +       x
  Rus                  +       X   -   +       X       +       +
  Chn  +               +       +   -   X   +   -       +
  USA                  +       X   -   X   +           +       X
  Jpn  X               +   X   +           X           +
  Fra                  +       +       +   x           X       X
  Ind                  +       +   -   +           X   X       x
  Per  X               +       +                   x   X       +
  Azt  X               +       +   -   +   +           +   -
  Zul  X               +       +       +   +           +
  Iro  +               +       +   -   x   +           x   
  Eng                  +   X   +                   X   X       X
  Mgl  X               +       +       X   +           +
  Spn                  +   X   +       +               X   -   x
  Sca  X               +   X   +           +           +
  Ott         X        +       +           x           +       +
  Cel  X               +       +       x               +       x
  Ara                  +       +   -   +               +       x
  Car                  +   X   +   -   +   +           +        
  Kor         x        +       +                   x   X       +
  Sum                  +       +       +       x       +       x
  Hit  x               +       +       +   +           x         
  Ned      -           +   x   +       x   +           +         
  Por                  +   x   +           +       x   x   -     
  Byz      -           +   x   +           x           x       x 
  Inc  x               x       +                   x   +       x  
  May      -           x       +       x               +       x 

  X = build often
  - = removed
  + = added

The algorithm to get the above table, starting from the stock build preferences, is as follows:

1. Add Offensive units to all militaristic civs and to Iroquois.
2. Remove Defensive units, Growth, and Explore from all civs.
3. Add Workers, Air Units, and Trade to all civs.
4. Add Happiness to all religious or non-scientific civs that don't have culture flagged.
5. Add Culture to all scientific civs that don't already have both Science and Happiness flagged.
6. Add Production to all civs with fewer than 6 build-often items.
7. Remove items so that all civs have a maximum of 6 items (Science from China).

[pvzh]

I think, you can safely clear out Explore units or set them to Never. AI does not explore (only some naval exploration after navigation and/or magnetism) and does not need to really: it has knowledge of land masses and resources for the purpose of expansion.

[alexman]

Yes, you're right that the AI doesn't build explore units even if it's a build-often.

So we could remove Explore from Aztecs and Spain, and replace it with Production. I'll edit the proposal.

[Theseus]

Originally posted by alexman [*]Remove Defensive units, Growth, and Explore from all civs.

I like it all (is this what's currently in the AU Mod?), but am concerned about this set of choices.

Defensive units: What does this mean for AI civs such as Greece and Carthage?

Growth: Fine.

Explore: Because they don't build such units anyways?

[alexman]

Originally posted by Theseus

I like it all (is this what's currently in the AU Mod?)

Currently, there is no change to build priorities in the C3C version of the mod.

Defensive units: What does this mean for AI civs such as Greece and Carthage?

These civs don't have defensive units flagged, even in stock.

Explore: Because they don't build such units anyways?

Yup.

[ducki]

I would think that a UU would override any flag, and since these two are at the beginning of the path, not having any to upgrade wouldn't matter. I'd wonder more about France.

[Theseus]

Then I vote yes.

[Stuie]

Nice work.

And I'll add a YES vote.

[ZargonX]

Looks pretty solid. We'll have to see how it handles in testing

[lockstep]

YES.

I'm confident that it'll work - the changes are similar to the PtW version of the AU mod.

[alexman]

I'll add my yes vote and say that it's time to vote, although it looks like the proposal has the required votes even before the official voting period.