Exciting AI improvements.

[franlato]

Blake, can Firaxis pay you to improve the war AI for the next patch??

[Solver]

I have to agree here, it seems that an expert-based system is much more efficient for Civ4. Not to say that a genetic approach is useless, but it would probably indeed take an unreasonable amount of time to achieve any results. Blake explains very well why. And genetic testing would also likely see some good-algorithm AIs have poor fitness merely because of poor luck, as that's a part of Civ4.

[Diadem]

Well there's always luck involved when you evolve algoritms. That's why you need a lot of testruns per generation - or alternatively a very large population size and number of generations (which is the way that nature does it - it doesn't run one live a 1000 times, it runs millions of lives for millions of generations).

So for civ, expert systems are the way to go. At least until civ 7 or 8



Anyway, I have an idea, sort of. The AIs always seem to leave a lot of units in their cities. Often I wage wars where for example they have 10 cities with 6 units each, while I have 10 cities with 1 unit each, a reserve defence force of some 5-10 units and an attack force of 10-15 units.

In such a situation I easily obliterate the AI, with about half the units he has. I take out his cities one by one, without any problems.

If the AI would be less sticky with city garrissons, it would leave only 2 units in each city, throw 40 at my attack force, completely obliterate it, and then overrun my civilization.

I think there is major room for improvements here... The AI needs to be made much more flexible with city garrisons.

[fed1943]

It would be possible to say the computer something like:

Try and avoid to fight with a small portion of your forces against all or

a big portion of oponents'?

Best regards,

[zeace]

The real key to the expert system isn't even that one expert can beat a neural net. Blake has been drawing on the expertise of all of us. I enjoy going back and reading strategy threads from a year ago when the game came out: "What are we doing wrong? Why are we all bankrupt? Just when my army starts rolling it disbands?"

While I'm sure Blake has hundreds of hours of play time (Don't even try to calculate it, it's scary), the entire experience of everyone posting is in the millions of hours. And we've done lots of trial and error stuff just like an adaptive AI could do. But we can all see the obviously dumb stuff and avoid it, so our hours of play time correspond to hundreds of hours of simulation time. So now we have hundreds of millions of simulation hour equivalents.

Of course the AI plays a little faster than us, but our collective knowledge is staggering. Just ask the poor testers for this game. I'm sure they put thousands of hours into testing it, but that's nothing compared to the millions of hours we play it. Of course we're going to find more bugs.

PS. Thanks everyone for every post you've put on this forum so that Blake can learn as much as he can so he can make a great AI for all of us. Yay Blake

[kniteowl]

Hey Does the AI already know how to Specialise Cities after they've settled a city?

Like a City that mostly has tiles that have Food >=2? (basically grassland or floodplain tiles) to cottage as a commerce/research city?

or a Production City That basically has many Hills to mine suported by the Food Surplus from Floodpains and Food Resources?.

and So on etc

[Blake]

Nope.
I gave it some rudimentary understanding via my new worker automation code... it'll terraforming certain cities as farm/mine, if a city really needs food to work resources (like silver mines), it really gets farms! This on the whole works really quite well and is one of the more impressive changes I made.

Unfortuantely the rest of the City AI does not know what the city is terraformed as... it wont nessecarly build a wonder in the city terraformed as production... so more work is needed still.

[kniteowl]

Kool your a kiwi... didn't realise and here I thought you were an amazing person improving the AI overseas LOL

Another question Concerning Spiritual Civs

How often do they switch civics?

When I play a Spritual Civ I go Switch Crazy going from Slavery to Selfdom and back almost every 5 turns depending on the circumstances. Sometimes I also do it with Organized Religion and Pacifism.

[kniteowl]

Another question, do you plan to improve the AI on archipelago maps in the future?

AI's are terrible on those Maps, I had one AI settled it's Second City on the other Side of the world from it's Capital, that didn't make sense at all, The city was pretty Good, the logistics of defending that city would proabbly be a nightmare.

Also the Strategy in a archipelago game is totally different, you generally research using the commerce from sea and ocean tiles. Production Tiles are Quite Rare (eg forest and Hills) but there's Plenty of food so slavery is a must

the AI's usage of slavery has considerably improved by you as far as I can see.

Would code the AI to play Differently bettween normal maps and a archipelago maps?

[Tattila the Hun]

Originally posted by Diadem
Anyway, I have an idea, sort of. The AIs always seem to leave a lot of units in their cities. Often I wage wars where for example they have 10 cities with 6 units each, while I have 10 cities with 1 unit each, a reserve defence force of some 5-10 units and an attack force of 10-15 units.

In such a situation I easily obliterate the AI, with about half the units he has. I take out his cities one by one, without any problems.

If the AI would be less sticky with city garrissons, it would leave only 2 units in each city, throw 40 at my attack force, completely obliterate it, and then overrun my civilization.

I think there is major room for improvements here... The AI needs to be made much more flexible with city garrisons.

Sometimes it's because of happines problems...

[Diadem]

Well of course there are sometimes reasons to have many units in your cities. But in general, the AI is just terribly inefficient with its units.

If I have 1/3 of the units the AI has, I will win. It won't even be a particularly hard war. That's just terrible.

Improving the AI effectiveness in warfare would be a major improvement. If they can use their units more effectively, we can do away with a lot of the bonusses they now need for units - making things more equal.

AI city placement and worker useage used to be a disaster. But Blake really improved this. The AI is now also smarter with civics, including usage of the whip. That means the AI can now build a decent economy. Good. I really think warfare is the next step.

The AI is so terribly dumb in using its units...

[Addled Platypus]

Originally posted by Diadem


The AI is so terribly dumb in using its units...

I think we have all seen the pinball movement too many times, this is a good change !

[kniteowl]

Another Nice Improvement to the AI would be it's usage of Great People, Have you guys seen an AI have a golden age in the early middles ages... WHAT A WASTE OF GREAT PEOPLE, their better off Becoming Super Specialist or lightbulbing techs.

should make it so the AI can only use Great People for Golden ages after or during the construction of the Apollo Program, it would make them a whole lot more competitive for the space race.

[JackRudd]

Trouble with that one is that it falls down spectacularly in No-Spaceship games.

[kniteowl]

Originally posted by JackRudd
Trouble with that one is that it falls down spectacularly in No-Spaceship games.

Then make the AI more likely to have Golden Ages during the Late Modern age or during thel ast 50 turns of a game when Space race is turned off.

It just makes sense that golden ages are much more productive during the late stages of the game.