Magic-Users - Start with the standard MU in all its Vancian glory, revamp the spells available (including the addition of many effects previously reserved for clerics) and add in an overcasting system whereby you can cast more spells than memorized and/or spells you can't otherwise cast. I'll probably do a separate post on the latter.
Scoundrels - I'm not a big fan of the Thief as implemented, but I like the idea of a class for the have-nots of society, whereby wits and trickery replaces swordplay or spellslinging. Still thinking about how to approach this mechanically.
Changelings - The class for fairy folk raised by human parents, humans raised by fairies, cambions, half-elves, half-orcs, descendants of the Nephilim and etc. Meant as a single class catch-all to replace the standard halfling, dwarves and elves. This class will probably end up with some spells, but they won't use spellbooks or Vancian magic.
Clerics as a class will not be allowed. Priests may or may not have a mechanical function, depending if I implement something like the Sin Point system previously proposed. But conjuring up miracles on command is not the province of the clergy, especially during a period so miserable that one chronicler note that Christ and his saints seemed to be asleep. For miracles you need someone like a Miracle Max or perhaps a Hildegard Von Bingen.
I'm also thinking of abolishing/modifying the normal weapons and armor restrictions. If I stick with d6 damage for everything, who really cares if the local Gandalf has a sword or not? I'd even allow armor to be worn, with the following penalties:
- helmet & coif (which, owing to the lack of platemail in the period, will be worth +1 AC) - Can't listen at doors, 1 in 6 more likely to be surprised.
- shield - Forget about spellcasting with that thing on your arm, buddy.
- chain hauberk - Must rest twice as often. Also, the fighters will be able to outrun you. If the whole party is being pursued by the Legendary Black Beast of Argh guess who gets eaten?