yesterday's post about the four classes, I dodged the original question "What would be your fifth class, if you were re-designing OD&D with the four original classes plus the one 'missing' class?" I would choose instead to re-design the two hyper-specific classes to be broader, to allow any of the four to be recast for specific character concepts. But what if someone forced me to pick a fifth class?
First, let's assume I'm still revamping the four-class system as previously described to allow ability tweaks tailoring any of the four classes to fit a specific concept. The arrangement I described seems pretty locked up: you have an axis of Mundane vs. Supernatural, with the latter covering any kind of supernormal abilities, magic, psionics, mutant powers. You have one class in the middle that can operate to some extent in either domain. You have a fourth class that covers hybrids of the three other classes. You could create more classes if you came up with a horizontal axis to go along with this vertical axis, but most of the ideas people have come up with, like the Law/Chaos axis, work better as modifiers to class than as a part of class itself (although DCC seems to do something like this.)
But I did toy a bit with the idea of inverted classes like the Fool, the Tourist, the Barbarian, the Noble, and the Elite Warrior/Cavalier. As the last one suggests, these are really one of the main four classes, plus an ability or two, plus limitations, with the emphasis on the limitations; these are what make the class distinctive. I could see going with a class system of Fighter, Talent, Magic-User, Hybrid and Inverted. But, even though I didn't come up with examples of Inverted Magic-Users and Inverted Clerics, it seems more like a method of modifying the main four. Of course, we could probably say the same about the Hybrid...
I also toyed with the idea of a character "buying" just one of the three abilities of a given Talent, such as taking just the stealth abilities of the Thief. I tentatively called this the "Single Talent" class, although we could expand it to include a Single Spell option. But again, it seems more like a method of modifying classes... and again, we sort of do this with the Cleric, who is functionally just a Fighter/Magic-User with limitations on both powers.
So maybe my five classes would actually be six classes: Fighter, Talent, Magic-User, Hybrid, Inverted, and Add-On.