Yields from central city tile (possible bug, or maybe I'm confused?)

[SullySaltlicker]

Inca's UA makes every mountain yield 1 , 1 , and 1 starting in the Ancient Era. I started a game as the Inca and noticed some weird things going on with my capital's starting yields when I settled on a mountain with vs. without a river. I settled my capital on a nearby mountain between some rivers and the city "improvement" itself is upgrading the central tile to 4 , 1 , 1 , and 1 .



This was weird to me because, according to the Civilopedia page "City Locations and Yields", cities on mountains get at least +2 . It seemed like my mountain bonus was overridden by the fresh water bonus, which gives +1 :



So I tried settling on a mountain with no fresh water and got this:



A central tile with 3 , 2 , 2 , 1 . I got more production as expected, but now the bonus for not settling on hills or fresh water got applied as well. I was going to file a bug report about this, but then I decided to start a game as a different civ and double-check that city tile yields were applying properly with other civs. So I booted up an Assyria game and got this:



My city tile has 3 and 1 , but I'm on plains (1 , 1 ) with fresh water (+1 for cities), so should I only be getting 2 ? Looking back at the first Cusco picture, I should be getting 1 from the Incan UA, and 1 more from the rivers, yet I have 4 . Cusco was set up between 2 rivers, so I checked and confirmed that the fresh water bonus was not be applied twice by settling on a mountain with only 1 river, and I got the same 4 yield from my city tile.

I feel like I should file a bug report but at this point I'm a bit confused on what I should expect to be getting from my central tile in the first place.

If anyone could explain all these yield scenarios it'd be a big help.

 

[Rekk]

Everything you see is intended behaviour. The Civilopedia entry is slightly out of date, as non-freshwater mountain settles give +.

If you are on a hill: 22;
Otherwise, if you are on a fresh water tile: 31;
Otherwise, if you are on a mountain: 221;
Otherwise: 211.

 

[SullySaltlicker]

So the default yield from the city is 2 , and the the only discrepancy is that mountains give 1 1 instead of 2 ?

How does grassland/plains/tundra factor in?

 

[Rekk]

How does grassland/plains/tundra factor in?

They don't.

Cities essentially take the tile that is beneath them, then modify them to satisfy minimum requirements.
Cities always have a minimum yield of 21. This means a flat grassland tile gains a , a flat plains tile gains a , a flat tundra tile gains , hills tile gains 2, a snow tile gains 2.

Additionally, depending on location, there are additional effects:
Flat Freshwater adds .
Flat No Freshwater adds .
Mountain Freshwater adds .
Mountain no Freshwater adds .
Hills don't add anything.

These effects give you the distribution described above.

Looks like there's one caveat: don't settle on a snow hill, as it only gives 21 (but flat settles will give 4 yields).