Traits that modify tile yields

[trystero49]

I'm looking to implement two different civilization traits. One trait is an increase in food/gold yield on certain bonus/luxury resources. The second trait is an increase in gold yield on trading posts in tundra. However, the XML tables available don't seem to support the ability to implement these UAs. How do I go about doing it?

 

[Tomatekh]

Use the Free Building XML tag for the trait, then make a dummy building that no one can build that adds yields to specific resources/terrain and give that building to your civ. <Table name="Building_ResourceYieldChanges">. Specifically boosting one improvement on tundra, might be trickier.

 

[trystero49]

Yes, I thought of that, but I was hoping there was a better way. I guess not.

There doesn't appear to be an <Unbuildable> tag. Could I make it unbuildable by setting build cost to a negative value? I assume if I don't give it a tech_prereq it won't appear in the tech tree. Is there a way to make it invisible in the city screen?

 

[Tomatekh]

Setting the cost to -1 should make it un-buildable. Not showing in the city screen requires some Lua work. I think someone has actually written the code for that and it's floating around on the forums somewhere (maybe not posted in a mod but in a thread).