changing hex yields

[dagriggstar]

...How ?

My (overall) aim is to make different terrain the "best" terrain at different stages of the game, but obviously to do this I need to change the base yields. However I cannot for the life of me figure out how to even change one piddly little thing...

I mean, on civ IV I'd just make a new folder, drop an xml file in, change the relevent value and I'm all set. Like 2 keystrokes. (If there is still a way to mod the civ IV way, I'd be ever so grateful to anyone that knows where to drop the files!)
Even on civ II, I could do something similar

But as soon as you force me to use a program to make these changes ????????? Confusing !!!!

As an example, I am trying to set the initial food on grassland hexs to 0 (Just to prove to myself this is actually possible).

<Terrain_Yields>
<Update>
<Set Yield="0"/>
<Where TerrainType="TERRAIN_GRASS" YieldType="YIELDFOOD"></Where>
</Update>
</Terrain_Yields>

And also
OnModActivated -> Update database -> CIV5Terrains.xml

What am I missing here

 

[TW_Honorius]

<Terrain_Yields>
<Update>
<Set Yield="0"/>
<Where TerrainType="TERRAIN_GRASS" YieldType="YIELD_FOOD"></Where>
</Update>
</Terrain_Yields>

for me it works after i added the "_"