Hi, relatively new to tile based 4X games. I was playing and was at war with an AI. I started to notice that I was getting stomped because all of the units the AI threw at me had at minimum veteran level 1. Given that they seem like they are freshly produced, how is it that they all are like that. Is there a research or a constructible? I might have just overlooked something but any help with this is much appreciated. 

Some cultures can do this kind of things:
https://humankind.fandom.com/wiki/Mycenaeans

https://humankind.fandom.com/wiki/Soviets

The first veteran level is obtained with 25xp

DNLH wrote:

Valid points, but I've seen non-Mycenaean AI pump out veteran units while in the classical era. There is possibility that they spammed Parade, but good luck trying to replicate that, while still building districts, infrastructure and units.

Not that it matters, because Amplitude, in true Amplitude fashion, devalues experience points and late-game you'll be pumping out units one kill away from top veterancy, if not third level off the bat, because units produced in city with Armory will be more experienced than actual veterans of ancient/classical wars half of the time. Two more veterancy levels would be ideal, preferably with prohibitive exp requirements, so you can't just buy all the iron for it.

I don't know, I had an army full of 3 stars units, the old and the new ones... More veterancy levels, why not, but better to make them hard to get then! If you start with one or 2 stars, and fight a lot, you will not take a long time to get the third veterancy level! You can even choose which unit get the last it to maximize xp on it iirc

About the "non-Mycenaean AI pump out veteran units", there are other ways, like Babylonians who can search tech from the next era, or just naturally getting experience from fights...