doctorbadwolf
Heretic of The Seventh Circle
It depends on how specific your concept is, and how much mechanical support you feel you need to adequately express it. I like a certain amount of front-loading, but only provided that there are still interesting build choices to be made later down the line. For me, somewhere between 4e Essentials and 5e would be the sweet spot. I would want the root archetype (which I’ve been calling “Class”, but I would be open to it being called something else) to give the character access to their spell list and/or fundamental martial abilities, and for the next level down the customization tree (which I’ve been calling subclass) would expand on that baseline with other spells/abilities and/or new ways to utilize the fundamental abilities. A bit like how a 5e Cleric has the base Cleric spell list, and the different domains give them access to other spells. Or how in 5e Essentials, every Defender class had the Defender’s Aura Power, and their own Power or Powers that interacted with Defender’s Aura. If I were to iterate on that concept, Defender’s Aura would be a class ability, and the Powers that piggyback off of it would come from Subclass. The next level down would be your more specific abilities that you use to refine your concept beyond the Subclass.
Another comparison would be something like the Dragon Age games. Class determines what ability trees you have access to, the Ability trees determine what abilities you have access to, and your ability choices determine what your character can do. I would do something similar, only the Ability trees would be subclasses.
There would definitely be room for different magic users using magic in different ways. The class would just determine which list you choose your spells from (which is why different magical Power Sources like Arcane, Divine, and Primal would be seprate classes in my take, instead of unifying the wizard and cleric into a single magic user class). Subclass would determine how you use those spells. So, looking at 5e as an example, Wizard, Sorcerer, and Warlock would all be subclasses of the base Arcane caster class. They already have very similar class spell lists in 5e, so I would just simplify by giving them all the same class spell list. Then the Wizard would cast spells from that list Vancian style with the spellbook, spell memorization, and spell slots. The Sorcerer would go all-in on the Sorcery Point concept, learning a limited selection of spells from the Arcane list and spending sorcery points to cast known spells. The Warlock would probably work similarly to how it does in 5e, bypassing the whole spell slot system and using Rituals to cast spells from the Arcane list and Invocations to modify their cantrips and spells.
I get where you’re coming from, but frankly I think that is more complex to understand than using distinct classes, and keeping things like power source somewhat behind the scenes. Power sources are useful, for sure. Wizards get all arcane spells, cleric get all divine, druids get all primal, would make sense.
At some point, though, you’ve got “martial” classes in an umbrella getting features that don’t make sense for them, or “defenders” in an umbrella getting features that don’t make sense for them. Rogues and monks both get evasion, and that makes sense, but they get very little else the same, which also makes sense. If monks go under the same umbrella as fighters, they don’t get what, armor and weapon proficiencies of a fighter? Maybe they are under the Psionics umbrella, in which case they get the base stuff of a Mystic, basically?
Or, ya just build eachclass, making decisions on a case by case basis, instead of having to fight against incidental shoehorning situations.