Does the AI pay to upgrade it's units

[Pounder]

Does the AI pay to upgrade it's units or does it just keep building new units.

I see the AI disbanding workers, but never see it disband military units. I see ancient units walking around in later Eras, makes me wonder.

 

[Doc Tsiolkovski]

They do upgrade, if they have the cash.
Naturally, this doesn't happen too often; on the lower levels, no AI has enough gold, on the higher levels, they often build that many units, they still go bankrupt.
An AI with a heatlhy economy will upgrade anything, though. You notice this with TOW for Civs with resources; in that case, they won't build TOWs. However, they use quite a lot TOWs offensively = former Archers/Longbows/Swords.
Another example are Caravells and Galeons of Byzantium - often used to attack other ships (former Dromons, of course).

 

[JMK]

The AIs pay to upgrade their Units.
You will see a lot ancient units when the AI do not have the cash to upgrade units.
You may also notice that the AI (if not yourself) that hold Leonardo will more likely upgrade its units than the other ones (cheapper).

 

[morchuflex]

Another example are Caravells and Galeons of Byzantium - often used to attack other ships (former Dromons, of course).

That's why I edited the rules to make Dromons upgrade to frigates, instead.

 

[sadu]

Yeah going from Dromon to caravel is a downgrade in my opinion. The dromon lethal bombardment owns anything the caravel has to offer.