what is it, and what is it good for. (absolutly nothing huh!) no, seriously, if anybody knows what it is, please post me. thanks.
Fog of war is the area you can't see (or don't know about) cuz you ain't got troops there. Ie, any blacked out/greyed out part of a map, that you don't have unit intelligence and/or terrain information for, is "fog of war."
Without fog of war you couldn't sneak around, ambush, bluff opponenets etc. Not that you do in this game, the game cheats outrageously (notice the bugbears always know who has the lowest strength and zero in their trips on them?)