Do the AIs get combat strength bonuses?

[dailyminerals]

In the combat preview window, the explanation about where bonuses are coming from are so vague that they might was well not be there at all. Is there some kind of massive bonus the AI gets to its combat strength, or do they get like three promotions out the gate when they build a unit? So often I run into units with like 50% combat bonuses from vague things like "terrain", when there's nothing inherent to their unit that would grant that bonus. So what exactly is going on?

 

[andersw]

Yes, the AI gets MASSIVE cheats for combat.
As you can see here:
https://civ-5-cbp.fandom.com/wiki/AI_and_Difficulty
The free exp and extra exp in combat are minor since they tend to throw away units a lot (compared to experienced players).
The big thing is probably the massive resistance cap "Maximum CS/RCS bonus (%) to enemy units from this player's warmongering penalties", this usually kicks in when you have captured a city and will likely never go away, this cap is a huge factor in making warmonger play more difficult.
On higher difficulties you can get into situations where your Tercios struggles vs Swordsmen, this makes melee units mostly a block of defence for ranged units unless they are very very promo heavy or you manage to surprise the AI.
This can make the first war feel as "oh this goes well" and after you have your first vassal, really hit a wall.

There are ofc terrain bonuses, hill, forest and a small one for desert.
There is also some niche cases, Iroquois gets +20% from nearby natural wonder, greece gets up to +25% from Citystates (and hoplites more on top for near a friend unit) for example.
(I guess there could be more if you also use 3rd and 4th unique component mod)

 

[dailyminerals]

I'd argue that in the development of vastly better tactical AI that this blatant cheating is no longer needed, at least to the magnitude that's seen currently.

 

[Heinz_Guderian]

I honestly think it is totally fine with the levels that are now. The AI is vastly improved but a scripted AI will never be able to match a decently competent human no matter how well you program it. You would need DeepMinds AlphaZero to outperform human players So the AI lose a lot more units than a human player, and therefore needs to have boosts in experience etc. Again I am not super great at this game but I fare well against deity AI in combat anyway, and oftentimes I reach higher levels for my units than the AIs because they stay alive throughout the game.