Thanks for the reply - yes, I made the changes while MTW was not running, and I started the game to see if they went into effect.

I think now the problem is that I was attempting to change a character who was already present on the map. (That rebel hero is present in Reget from the beginning. If I want to change *his* starting loyalty, I'm guessing I would need to do that in startpos.txt.)

When I made a similar change to the "l" value in a Mercian hero, who showed up after the first turn, the loyalty indeed matched what I had set it to.

So, it looks like the "l" value in viking_heroes.txt is for "loyalty", which I'm happy to confirm for myself :)

Incidentally, drone, I've looked around the place a bit and I'm wondering if you know of any comprehensive guides to the MTW txt files - i.e., what their functionality is, and how different elements can be used? I'm guessing that if there were any such guide, it would be here already, or at TWC, but I've looked through both places and haven't found anything that really goes through the files in detail.