How does the AI price resources and luxuries?

[tjs282]

Does anyone have any info or links to studies regarding how the Al prices its excess Strategic resources?

In my current game (Std, Random-map [60% Cont], Random-civ [Maya], Random-opponents, Demigod), there is no Saltpeter anywhere on my originally 4-nation Continent (USA extinct, Egypt reduced to OCC, currently making slow gains against Babylon after they started a third war against me), so I've had to import it from the other continent instead (Iroqois, Aztecs, Portugal still hanging on, 4th Civ [China?] died before I made contact).

The first time I asked, the Iros and Aztecs (both with 2 spare Salts) both demanded >200 gpt, but with the Babs now fielding Rifles, I really wanted/needed Cavs + Cannon if I was going to make any headway against them. So I gulped and paid up, then spent the next 20 turns upgrading my vet Knights and spamming Cavs in pretty much every town (I'd captured SunTzu + Leos from the USA, and am playing with C3X, so already had plenty of captured Cats + Trebs to upgrade), in the expectation that the price would increase next time around.

But when that deal came up for renegotiation, Hiawatha reduced his asking-price, to just under 100 gpt! The only real changes in the interim were my substantially increased total military strength, and that the Babs have been Embargoed. Was that why I got a better deal the second time?

 

[BlackBetsy]

Does anyone have any info or links to studies regarding how the Al prices its excess Strategic resources?

In my current game (Std, Random-map [60% Cont], Random-civ [Maya], Random-opponents, Demigod), there is no Saltpeter anywhere on my originally 4-nation Continent (USA extinct, Egypt reduced to OCC, currently making slow gains against Babylon after they started a third war against me), so I've had to import it from the other continent instead (Iroqois, Aztecs, Portugal still hanging on, 4th Civ [China?] died before I made contact).

The first time I asked, the Iros and Aztecs (both with 2 spare Salts) both demanded >200 gpt, but with the Babs now fielding Rifles, I really wanted/needed Cavs + Cannon if I was going to make any headway against them. So I gulped and paid up, then spent the next 20 turns upgrading my vet Knights and spamming Cavs in pretty much every town (I'd captured SunTzu + Leos from the USA, and am playing with C3X, so already had plenty of captured Cats + Trebs to upgrade), in the expectation that the price would increase next time around.

But when that deal came up for renegotiation, Hiawatha reduced his asking-price, to just under 100 gpt! The only real changes in the interim were my substantially increased total military strength, and that the Babs have been Embargoed. Was that why I got a better deal the second time?

You know, that's a really interesting question. When it comes to luxuries, AI will charge you basically by your city count (kind of a proxy for the amount of happiness you can generate), and I assumed it that strategic resources are the same. It's a little bit under 1 gpt per city per turn for luxes. I haven't noticed any effect of the number of civs with extras of a lux (say both the Romans and Babylonians have extra incense) on the price.

 

[justanick]

You know, that's a really interesting question. When it comes to luxuries, AI will charge you basically by your city count (kind of a proxy for the amount of happiness you can generate), and I assumed it that strategic resources are the same. It's a little bit under 1 gpt per city per turn for luxes. I haven't noticed any effect of the number of civs with extras of a lux (say both the Romans and Babylonians have extra incense) on the price.

It is not city count, it is happy faces gained. This means that marketplaces can up the price by a factor of up to 4. Selling and rebuilding marketplaces can make sense in some cases.

 

[tjs282]

No, both the 7th and 8th Lux each give 4 Happy faces with a Market -- which is why the price is similar for both (but more expensive than the price for the 5th and 6th, which only give 3 Happies each).

 

[Lanzelot]

It is not city count, it is happy faces gained. This means that marketplaces can up the price by a factor of up to 4. Selling and rebuilding marketplaces can make sense in some cases.

Or sometimes it makes sense to pillage your own luxuries, buy the AI's one and then re-connect your own.
E.g. if you have 4 luxuries yourself, the AI's luxury would be the 5th, which would give you 3 happy faces. If you pillage three of your own first, the AI's is only your second, which gives 1 happy face, so you can now buy it at approx. 33% of the original price...

 

[tjs282]

My question, however, was about the pricing of Strategic resources, not Luxuries...

 

[justanick]

Or sometimes it makes sense to pillage your own luxuries, buy the AI's one and then re-connect your own.
E.g. if you have 4 luxuries yourself, the AI's luxury would be the 5th, which would give you 3 happy faces. If you pillage three of your own first, the AI's is only your second, which gives 1 happy face, so you can now buy it at approx. 33% of the original price...

Yes, that is usually way more economical. An exception to this rule could be OCC. But then again, why would you need that many luxuries in an OCC?

My question, however, was about the pricing of Strategic resources, not Luxuries...

I have no reliable information on that. But my guess is that there is some kind of utility-calculation involved. So you already having a strong army may decrease the utility and thus the price AI can ask of you. Still, this is just speculation.

One interesting test would be to buy nationalism and compare the price of saltpeter before and after the purchase.

PS: The price of strategic resources deserves a topic of its own. Hiding it in this large thread is plain wrong.

 

[kaskavel]

I have no reliable information on that. But my guess is that there is some kind of utility-calculation involved. So you already having a strong army may decrease the utility and thus the price AI can ask of you. Still, this is just speculation.

I think I have repeatedely noticed AIs not offer a single coin for oil after researching refining (but before they have the option to build something oil-based)

 

[tenny]

Does anyone have any info or links to studies regarding how the Al prices its excess Strategic resources?

In my current game (Std, Random-map [60% Cont], Random-civ [Maya], Random-opponents, Demigod), there is no Saltpeter anywhere on my originally 4-nation Continent (USA extinct, Egypt reduced to OCC, currently making slow gains against Babylon after they started a third war against me), so I've had to import it from the other continent instead (Iroqois, Aztecs, Portugal still hanging on, 4th Civ [China?] died before I made contact).

The first time I asked, the Iros and Aztecs (both with 2 spare Salts) both demanded >200 gpt, but with the Babs now fielding Rifles, I really wanted/needed Cavs + Cannon if I was going to make any headway against them. So I gulped and paid up, then spent the next 20 turns upgrading my vet Knights and spamming Cavs in pretty much every town (I'd captured SunTzu + Leos from the USA, and am playing with C3X, so already had plenty of captured Cats + Trebs to upgrade), in the expectation that the price would increase next time around.

But when that deal came up for renegotiation, Hiawatha reduced his asking-price, to just under 100 gpt! The only real changes in the interim were my substantially increased total military strength, and that the Babs have been Embargoed. Was that why I got a better deal the second time?

Military strength has in my experience never changed cost for strategic resources. However, the positioning of cities and cultural influence seemed to make a difference. If an AI was surrounded by cities and lots of enemy players, cost for strategic resources was higher. That seemed not to be influenced by total citizens or shield production in my empire. It also did not seem to be influenced by units which I could upgrade in case of trading the strategic resource.

Maybe there is now less pressurce on Hiawatha?

 

[Lanzelot]

I have moved the posts from the "Quick Answers" thread to here.

PS: @tjs282 : Sorry that I combined strategic resources and luxuries into the same thread, but I think the mechanisms behind it are very similar and it probably makes sense to investigate the two topics jointly.

 

[tjs282]

By the time the Saltpeter deal came up for renewal for the second time, the Babs were nearly dead.

Our continent is shaped a bit like a hammer, and when the war started, Babylon occupied the head, and Maya (me) fully occupied the handle. So once I'd cut down their initial rush, and was ready to start pushing back, I was almost immediately assaulting their first-ring towns, and it took a while to make any headway, because those towns kept flipping back (for the most part I preferred to recapture, rather than pass them off to anyone else).

But in the time it took to gut the Bab core, the Iros had managed to capture one of their outlying towns on the 'claw' to the north, and the Aztecs got a Tundra-town down at the south end of the hammerhead. And their price for Saltpeter had climbed to ~130 gpt -- possibly because I was now in a position to 'threaten' their towns?

Spoiler But I don't really care... :

...because over that same period, I got SciMeth + ToE (and got an SGL for Electricity, and saved it for Hoovers, even though that meant no new MGLs for most of the war), and RepParts + Rubber. So unless Hiawatha or Monty do something foolish, I think I'll be winning either by Diplo or Space...

 

[tenny]

But in the time it took to gut the Bab core, the Iros had managed to capture one of their outlying towns on the 'claw' to the north, and the Aztecs got a Tundra-town down at the south end of the hammerhead. And their price for Saltpeter had climbed to ~130 gpt -- possibly because I was now in a position to 'threaten' their towns?

I think that might be it, and maybe that the Iros are now directly bordering to more players?!

 

[theRUFFIAN]

I may be mistaken but I was generally under the impression that another civ’s mood toward you is the main factor for strategic resource prices. If they are polite or gracious, they will be more on board with you upgrading your army so you can keep pummeling the other civs (which kinda helps out the guys selling to you). If they are annoyed or furious, they would be worried you will turn your fresh new cavs on them…thus a higher asking price. Same for when you sell them stuff. They pay more if they like you.
I’ll have to test this out, I’ll get back if I find anything of value.