This is a wonderful game, and there is so much to it. If a merc gains in skills during a game do these gains carry over into future games or, everytime you start a new game, does the merc revert to the stats she came in the game with?

Thanks

Stat gains do not carry over. Each time you start a new game, the game reads the prof.dat file to get the stats of the mercs, then saves them to the current save.

As I recall, yes. File is located in Data\BinaryData and you can find an editor for it here. I think Proedit.zip should do the job, it is possible that there are a few other editors that work as well. Be aware that changes to prof.dat will require a new game to take effect.

Also, all of the above are for 1.12 version, if you use 1.13 then use Merc Profile Editor.exe to edit the merc stats. New game is still required.