XML is not for functionality: http://www.w3schools.com/xml/xml_whatis.asp. It exists to describe / store data. Wait for the Python to start doing things like random variables and if checks.

The only sensible way that "randomness" could be achieved through XML is if the game was expecting an element to have some sort of "probability" attribute.

I've tried this on multiple occasions but CANNOT get any code to work.

Here is the code for adding diplomacy based on charisma:

<GameModifier>
      <Target>Player</Target>
      <ModType>Resource</ModType>
      <Attribute>DiplomaticCapital</Attribute>
      -->
  <!-- Use the sovereign's charisma stat to determine how much diplomatic capital they get -->
      <Calculate InternalName = "Value" ValueOwner="PlayerSovereign">
        <Expression><![CDATA[[UnitStat_Charisma]]]></Expression>
      </Calculate>
    </GameModifier>

Doesn't work though. I wish it did, lol.

I've been trying to use this so that the gold per turn from a Merchant would be based on his stats. Thus, as a Merchant levels he'd be getting you more income. It'd do wonders for my traits and abilities mod.