I started the game at very easy setting after some tries to find out what were the differences between the dificulty settings.
I found out that very easy gave me more health and mana than the other settings and I thought that this could be a good start to kill Fergus without using a single potion (one mage with something like 340 mana at start give quite a little of level one magical missile attacks).
After several minutes (maybe one hour), I did shut down my computer and the next day I reloaded the game. I fought my second ghost then and died in two hits while my first ghost was killed without any problem the day before.
I thought : "what the ...?"
Then I noticed, that my mage (that had increased in level since Fergus' death) had only 280 mana and the life was lower also.
I hit space to pause and escape to go to the menu and checked the difficulty level ... it was very easy.
I thought that there was a bonus only when you were at low level to help out a little, then, (being a developer myself) I thought about bug ... hehe
So I changed the difficulty level to action, applied the settings, changed back to very easy and applied the settings.
Back to game: miracle ... got 380 mana (I think), but unfortunately only 280/380 and something like 75/95 in health.
Since then, each time I start the game, I must switch the game setting to Very Easy BEFORE loading my save game if I don't want to have lower mana and health ...
By the way, does someone know exactely what are all the changes between the difficuly levels (with numbers, like monters have 40% more health and hit 50% harder in hardcore ... <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />)