I remember talk about classes and skills before, but it never went anywhere. Folks could not figure out where to start, or agree on how to go about it, as we all have varying opinions. Despite the stall in addressing this, I think there is a good deal of interest in the topic. The
Mazes & Mutants sub-rules seem to be unpopular, if only for the lack of playable Androids, the lack of separation between races and classes, and a mutation system the feeds like spell slots. People just love the idea of playing an android wizard/scientist, or a half-elf fighter/thief/scientist.
Personally, I would rather have it so that you roll-up a character normally as per the MF rules, but as you gain experience points, you may allocate EXP to attributes and classes. As you gain levels in Fighter, you gain more to-hit, melee damage and hit point bonuses, and you get more attacks per round. The Thief class only improves your Thief's Abilities, like how the Tech-User class get better with figuring out artifacts, and the Magic-User class can cast more and better spells (for those players who like to play Thundarr-type settings), with none of them improving your combat abilities. On top of that, high and low attributes would effect the amount of EXP you'll need to get to the next level with the related class, in the same way prime requisites works. So a character with high STR and some levels in Fighter would not gain bonus EXP at the end of the game, but a discount to the amount of EXP needed to gain a level in Fighter. I have yet to figure out how to apply this system to saving throws. Classes might just add (by subtracting) bonuses here and there to your base MF save scores, as you progress. Personally, I would rather cap so players could focus on multiple classes, then to build on high-level, single-class characters.
To make the above work, you ether have to keep with the basic classes, or find a way to incorporate the "sub-classes" (Rangers, Druids, Paladins, etc.). I have thought of ways of making them work for the sake of other players, but I could to get them to work. In a systems were your combat abilities are tied with the Fighter class, were would the Ranger or Paladin fit in the mechanics? There was other issues of overlap. My bast idea with them was to make their EXP requirements so high, one would need all of their required attributes high just to off-set the inflated cost, to maintain their rarity. But for me, I don't even care for those classes, as I feel that "classes" are generalized concepts, instead of archetypes into themselves. That is, a Fighter is an open-ended warrior type that allows players to come up with their own archetype (amazon, barbarian, knight, etc.), while sub-classes are just specific archetypes.
My ideal classes are: Fighter, Thief, Healer, Tech-User, Esper, Magic-User, and Leader (of Men).
The Healer has skills and/or abilities that can be used to treat characters, and to test/treat food and water for contamination, much like a Cleric without being one. (I was never a fan of the Cleric class -- I would rather fold them into the Magic-User class, with a deity/spirit/demon lord/etc. as their instructor.)
A Leader (or "Leader of Men") are diplomats and military commanders. This class can bolster your retainers, give you followers, and provide you with other social benefits.
Mind you, all this was just a passing thought...
Oh, here are some links:
Skill system ideas,
classes,
favorite race/type, and
classes at the MF Wiki. I hope they would be would be helpful to anyone.