Sometimes the AIs will play exactly against themselves:
- Korea/Babylon will go Honor and or Piety and neglect science. I've seen games when Babylon were dead last in technology
- Germany proposed "embargo city states" in one game.. What??
- Sweden neglect their UA and often DoW everyone on the map, with varying results
- Siam really love stomping CSs that are allies of their enemy.
- Shoshone forget how to expand
The AI does not have triggers set in its code to check for the unique abilities those civilizations. Siam is the only exception really, and the best I can do to explain it is that flavor rolls simply didn't go the right way in that game. In case you don't know, the AI generates adds a random number between -2 and 2 to each of its flavors at the start of the game (a different one is rolled for each flavor), and I call this the "flavor roll".
Korea/Babylon have a rather high science flavor, but it's not high enough that a bad flavor roll couldn't override it with, say, offense flavor.
Korea doesn't actually *know* about its UA, the way it's implemented is a high science flavor coupled with a high wonder flavor, but flavor rolls could easily work against it.
Babylon doesn't know that it receives Great Scientists like crazy, so it doesn't know that it should focus on producing Great Scientists.
Germany does not realize that its UB works off of trade routes with city-states, so it will propose city-state embargo just like any other civ.
Sweden has no idea that its UA is based on DoF's, so it won't actually emphasize DoF's. I don't even think I need to mention that it doesn't know about GP gifting, either, though outside of Great Generals, it's not really worth gifting GPs anyway.
Shoshone doesn't factor in the extra tiles it will get when choosing a city to settle, though arguably that's not as important as the actual expansion flavor behind building settlers to settle those cities. Expansion flavor is a bit tricky as well, since there are a lot of AI military, economic, and city strategies that modify it based on various conditions. BTW, the fact that, AFAIK, AI Shoshone Pathfinders don't get bonuses from ruins might also hinder the Shoshone AI: the way the code works is that if the unit that uncovers ruins has the Pathfinder trait, the game will fire up the relevant menu if the "active" player is the player whose unit stepped on ruins, otherwise it will do nothing. Since the "active" player is always a human player, Shoshone AI will pass the "does my unit have the Pathfinder promotion?" check, then proceed into the clause that says "if this is the active player, fire up the menu, otherwise do nothing", fail the check, and consume the ruins without actually getting any bonuses.