My idea a bit not fleshed out.
There are four classes: warrior, cleric, rogue, mage. These classes set some basic options: HD, spellcasting progress, saves, basic proficiencies. Each class gives a pool of points to buy class features with. These features include weapon/armor proficiencies, abilities like rage, smite, turn undead, metamagic, etc. Some abilities have prerequisites like level or other abilities you need first, but if you belong to that class, you can spend your points to buy your classes abilitiesn. You can also poach off the other classes lists, but they cost more points than if you were a member of the normal class. So if your a warrior and want to pick up some spells to be an EK, it would cost you more to learn magic then if you were a mage. Some basic abilities are reprinted for multiple class lists as well.
Warriors are the primary fighting type; d10 HD, Proficient in all weapons and light/medium armor. Some of the themes provide include Fighter, Battlerager, Oathsworn, Eldritch Knight, and Marshal. You can follow the theme or do you own thing.
For Rogue, you have d8 HD and a large selection of skills to be proficient in. You can buy a lot of skill-based abilities as well as skirmish and flashy abilities. The Thief, Bard, Assassin, Ranger, and Martial Artist are options.
Mages can select Intelligence or Charisma as a casting stat and initially select either Arcane (elemental/combat magic) or Mesmerism (enchantment/illusion) spell lists. Mages can represent Wizards, Sorcerers, Beguilers, and Artificers.
Clerics are primarily priest role who can pick Wisdom or Charisma as a casting stat and pick from Divine (healing) or Primal (buffing/summoning) magic. Most options here are focused on domains to represent Life, Nature, Trickery or War, but the Shapeshifter Spiritwalker, and Pactbound reside here to.
As the game grows, new archetypes with new abilities get added to the core classes. Eventually, a fifth class (psionicist) could be added.
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