08-02-2003 09:09									#1
	Next question: AI, money and trade negotiations. Put an end to popups!

What determines how much money the AI asks for in trade negotiations?

Is it (1) how much reserve cash I have compared to them, (2) how much I make per turn compared to them, or some combination? Does anything else factor in? (E.g. relative culture levels, relative military strength, etc.)

How does the AI's aggression level factor in? I've noticed that in AI-to-AI trading, the more aggressive civs seem to end up with more trading agreements than the less aggressive civs. This phenomenon seems to be irregardless of which AI has more cities (and presumably more resources to trade with). *cough* mind you, this observation is considerably less than scientific and could be patently false.

	08-02-2003 17:21									#2
	Increase the size of your Attachments

Underseer, it depends heavily on what you're trading for.

Luxuries values are somehow depending on the size of your empire, and how many people will get happy as a result from that. Because of marketplaces, your 7th or 8th luxury is 4 times as valuable as your 1st or 2nd, and the AI knows that, and uses this in negotiations. Further, the size of your empire counts, when negotiating for luxuries you might want ot do that before a tank rush gives you 30% more territory, it will cost you less.
What an AI is willing to pay for a lux is calculated the same, so you're always better of to trade the 7th or 8th lux to him instead of the 4th.

Tech costs depends on a number of things, first of all the value (in beaker cost) of the tech. This will of course depend on map and difficulty settings, and on the number of civs that already know the tech. It's basically a number / beaker price, so if you roughly calculate this ratio once in a game when you're buying a tech from the AI, you can calculate when you have a new tech how much others will be willing to pay for it. Remember that the first you sell it to will pay most, and that by trading it with one civ, another can instantly finish the tech as the beaker cost decrease (they may not want to trade it to you, except for 20 gold or so. Don't do that, as it will safe them 1 turn on research, by letting them end an already finished tech, hey will waste all beakers of that turn)

Other factors are depending on how valuable a tech is in game. I'm not sure if resources count (could be), but wonder techs are certainly a lot more worth to AIs as long as the wonder hasn't been built yet. And, government techs are more valuable to them too, even if they don't plan on changing.

Last factor is something to do with honor, or friendlyness. But apart from refusing to trade gpt to dishonest civs, the effect is rather small.

ROPs and alliances are depending on diplo stance with you, size of empire, and the relations to the targeted civ. If they are already annoyed with a civ, which they don't trade with, a war is easily declared with an aggresive civ. But try to break a lux deal by asking one of the parties to declare war, and you could find that all the gold in the world might not be enough.
Oh, aggresiveness also counts, of course. And this in result is amongst others a function of how aggresive you play yourself, the AIs will adjust to what kind of game you play.

DeepO

	09-02-2003 02:14									#3
	Full PM-box? Change here!

Thanks much!

PS— Belgian beer r0x0rZ!

	09-02-2003 02:22									#4
	Support Apolyton, buy GURPS/ Alpha Centauri

No problem, and it's nice to see you met our beers before

DeepO

	09-02-2003 03:23									#5
	Re: Next question: AI, money and trade negotiations. Enter the AD-FREE zone

I actually found a formula once:Partial and pointless formulae: resource cost
Everything DeepO says is, of course, right.

quote: Originally posted by Underseer Is it (1) how much reserve cash I have compared to them, (2) how much I make per turn compared to them, or some combination? Does anything else factor in? (E.g. relative culture levels, relative military strength, etc.)

For resource or tech deals, none of these matter.

quote: How does the AI's aggression level factor in? I've noticed that in AI-to-AI trading, the more aggressive civs seem to end up with more trading agreements than the less aggressive civs. This phenomenon seems to be irregardless of which AI has more cities (and presumably more resources to trade with). *cough* mind you, this observation is considerably less than scientific and could be patently false.

You are right that this has a big effect. I'm not sure about AI-AI trading because it's not obvious how many of those are fair deals. This is the most important factor DeepO missed out. You might want to look at AI - human trade revisited
Basically the aggression level of the AI civ is important at the higher difficulty levels and is by far the most important difference between civs for resource/tech deals. If they can afford it, it makes sense to sell techs to the civs with lower aggression levels first.

quote: Originally posted by DeepO Luxuries values are somehow depending on the size of your empire, and how many people will get happy as a result from that.

Somehow? For even numbers, it's linear. That's not somehow. That's exactly what you'd expect!

	09-02-2003 07:54									#6
	Avatar Enlargement: We've got the solution

Well, I'm not sober enough to go through all the numbers, but thanks for the links, Nor Me. Tomorrow I'll try to comment in full.

One miniature comment: I know about the AI-agressiveness level, but maybe it wasn't too clear from what I posted (hey, I tried to get 3 different trade-costs in one post ): I said that agressive civs were more eager to go for alliances, it's not something I missed, but something I might have put more clearly.

DeepO