Tech demands refused while capitulation offered?

[TheProvost]

I'm playing a standard map, pangaea, aggressive AI, 8 other civs, as the Americans.

I'm in the industrial age, along with the 4 other top AIs. I have two vassals, both still in medieval age. I was beelining for Riflemen and got them way before anyone else was close, and since the other advanced civs are all focusing on Democracy, Scientific Method etc they are still not on par with me militarily. They do, however, have some very nice tech that I had to ignore to get my military advantage: Scientific Method, Democracy, Nationalism, Music, Optics, and a few others.

My plan was to invade the Byzantines and push them to the point of giving me all their tech, thus cementing my dominance. I invade with a big stack of Riflemen and Trebuchets and grab two cities, including their capital, within 7 or so turns. At this stage they are already offering capitulation and one or two low level techs (Music, Optics) and all their gold. I instead ask for all their tech, no capitulation: they refuse! This is kinda weird, since if they're willing to roll-over why won't they give me better tech?

I figure I'll just take more of their cities, so I take all of them but one, a size 14 city so far south that it's mainly tundra and sea. I then demand all their tech - they refuse! They won't even settle just for Scientific Method! I tried a different tack entirely: demand capitulation then demand the tech: no dice, they just refuse to give it to me! I can't even make it a tribute demand, like I would with resources. So then I move my stack against their last city, knock it down to one unit - I can crush their entire civilization out of existence: I demand peace (not even capitulation) for just Scientific Method - they refuse! They are still offering my the two lowest level techs they have, capitulation and all their gold...

I am completely at a loss here - what is the AI's problem? Our relations are quite bad (he is Furious) but I am quite literally about to annihilate him, and have roughly 3 times as many points as him at this stage, what with him having only one city left. Is this normal? If so, am I doomed to be unable to get these techs out of him by force?

[Theben]

I would say so. It's probably part of the vassal programming that allows vassals to say "up yours" wrt demands for science while they give in to all your resource demands. I think under the circumstances the AI should give you whatever you want, sadly the game mechanics are against you.

[Tattila the Hun]

Consider, if they get give you your demands for peace, you can just crush them 10 turns later. If they capitulate, you are responsible for their safety, and they go on living.

[TheProvost]

That's a fair point Tattila, but it still suggests that they should give me all their tech, but on the condition I accept their capitulation. Hell, I've been very nice to my two other vassals, giving them a tech boost and some cities back. I'd do the same for Justinian if he would just cooperate! As it is, he's just pissing me off. The calculations are totally off - it makes no sense to keep offering me the two lowest techs and nothing more. He hasn't changed his offer but his situation is drastically worse than when I first invaded... I just don't get what the AI is thinking!

[inca911]

Getting a significant amount of techs boosts your civ up to the level of the other AI civs. I often feel the AI behaves as a single group such that once they have the lead they will not trade very much with you to let you out of the hole. This "AI Entity" would rather lose one finger on it's hand of five civs than give you enough tech to get a lead in the game.

[realpolitic]

If you're about to annilate him and there is no tech offers, it's obviously bad programming.

It would be rare for me not to take capitulation when offered - they might capitulate to an enemy, and it gives me a chance to move on - eigther to peace or war with another, with at least some advantage. As my vassals are now an asset, albeit sometimes minor, I trade or give them spare resources, they are usally my first choice for tech trades, and once my rivals get techs for more hammers on tile improvements, I give them to my vassals. I don't give them anything to improve their commerce, as faster science gives them more discession in what they do (I want to control it.) I'll give them the techs for city improvements that produce more hammers only when I anticipate a long period of peace, so they don't get distracted building factories when I want them to build units.

Accepting caitulation early has plenty of advantages.

[Unimatrix11]

I think this is, as Tattila already indicated, a matter of avoiding exploits. But i am sure, Blake will comment on this soon, and as he will, he might also make a statement about the "AI-entity". I got a bit of that impression, too, but not nearly as frustrating and annoying as it was in Civ2, where it was obvious, that everyone always ganged up against me in a most futile and annoying manner of constant mini-invasions, with the AI taking turns with it. I hated that.

[Tattila the Hun]

Mini-invasions? A different thing, but I've grown bloody tired of the AI, the turn after researching astronomy, sending one (1) galleon to some tiny city of mine to try to capture it... Now, I know he has about 400% more troops than me... But they're all on the other bloody continent! He can't get them to me!