If D&D AU doesn't start with a catchall fighter at the start and goes with many warriors, I could see
- A generic fighter class
- A generic Knight class with various flavors a subclasses
- A "European Barbarian" class that mimics movie Vikings, Celts, Goths etc but isn't called Barbarian.
- A Shieldbearer class for Hoplites, Impi,and Aztec warriors
- Unarmed Unarmored Chi Warrior
- Weapon and Armor using Chi Warrior
- An agile warrior class for bandits, pirate, swashbucklers, and highwaymen
- A Gladiator class to host all obscure or exotic warriors that need special mechanics,
- A magic warrior with spells
- A magic warrior with magic gifts
Interesting thoughts.
Personally I don't think there'd be any separation between "chi" and other "magic" that wasn't actual spells when it came to these classes in a modern D&D, because qi/chi isn't what it used to, popularity-wise. Warrior with magic gifts and weapon/armour chi warrior would probably be the same guy, and the abilities would probably be expressed in such a way that they could be seen as qi/chi-based or psychic powers (a la Lone Wolf etc.). I also don't think we'd see a "generic" Fighter at all, or if we did, they'd be a crap class nobody took (some RPG basically had this, I forget what).
I also think this is a bit too neat - I doubt subclasses would be planned initially. Instead I think classes would have quite a lot of options (because wargame characters by then would). And I don't think Gladiators would exist to "host" things - that's too neat and forward-thinking. That's like, second or third gen stuff at least. I think they'd be thinking more about archetypes, which basically breakdown to:
1) Swashbuckler-types. Non-magical. Likely incorporating Thief and "Robin Hood"-type archetypes as well as an array of conventional light-armour types. "Commando" archetype may well go here too.
2) Heavily armoured-types (who often also have a code of some kind and may well fight in formation) - Knights, Samurai, Hoplites, and I think Aztec Warriors would fit in here too if you just made their armour magically work better. Impi-type warriors are really just a cuirass + skirt short of being the same thing so would probably get that.
3) "European Barbarian" as you say, they wouldn't be called Barbarian (Reaver, maybe?), and they also actually include Maori warriors and some others. Big, tough, optionally a berserker (probably able to ignore wounds etc. even if not an actual berserker). Might well include some "brute force" unarmed stuff.
4) "Jedi"-types, including Lone Wolf-style stuff. Lone Wolf specifically probably wouldn't exist, but post-Star Wars fantasy? That absolutely would. I would predict that without D&D and post-Star Wars, there'd be a whole subgenre of "psychic warriors" in fantasy (not just SF). This would likely encapsulate "chi"-type warriors, because chi/qi was last "cool" as a concept in the 1990s (since then the concept of "inner energy" and quasi-psychic powers had become much broader), so Kensai and Jedi and Kai/Magnakai (hey look at all those "i"s!) would likely be the same class. Ninjas might also be in the mix.
I think those would likely be the "book 1" warriors.
Later on we'd get some kind of "Nature Warrior" probably - not D&D's Ranger, but Aragorn will have an impact, and I think other characters in fantasy will too, and we might well see them as some kind of "Eco-Warrior" to some extent. Re: Magic warrior with spells, I think this'd depend on whether they had multi-classing. My guess is they wouldn't, initially, have multi-classing, so yes, they probably would evolve this guy, who had Harry Potter-style spells (i.e. discrete spells with names, casting times, not just psychic powers which the Jedi-type would likely already have) combined with being either armoured or a swashbuckler-type (I bet they'd only pick one as it'd be "obvious" - eventually the other might well evolve).
We'd eventually see an unarmed martial-artist class separate from the Swashbuckler and Jedi, I think, inspired by games like Street Fighter. In fact it might be in the core book because of fighting games! I think they'd be their own thing though, rather than part of one of those other classes, with distinct mechanics. Probably not very Monk-like - i.e. no "purity" and "immunity" and "wall-running" (you actually see more wall-running from armed than unarmed martial-arts types in fiction, I'd suggest), but probably with rules for combos, special moves of a fairly magical kind, and some sort of "super bar" equivalent. I'd expect heavy Street Fighter inspiration with a side of anime.
Magic-user-wise I'd expect we'd have at least two starting classes for sure, as I've mentioned:
1) The "discrete spells" caster - i.e. they cast spells which have names, take time to cast, require gestures (and possibly a wand/staff), and so on. This incorporates everything from Harry Potter to a lot of Eastern spellcasters (Harry Potter is likely to land even harder in a D&D-free world note).
2) The "abilities" caster - i.e. they have various powers, which can be used at different levels of strength, and perhaps combined. This would cover various kinds of psychic and quasi-psychic, as well as a lot of superhero-inspired stuff.
I strongly suspect we'd see new traditions expressed as new classes, rather than subclasses or the like - so if someone wanted something like the Mistborn, whilst they're obviously "abilities"-based, I'd bet they'd be a new class entirely.
Whether we'd see an "Alchemist"-type class is an interesting question. I don't think it's as certain as some people do. The reason is that the whole idea is somewhat anime-influenced, and the anime influence is from anime being influenced by D&D and JRPGs (particularly the whole idea of potions and bombs).
Instead we might see a separate "New Age"/"Wiccan" caster, who would include alchemical elements - they'd be really heavy on candles, even more rituals, invoking the spirits (as opposed to casting discrete spells), making potions that do stuff and generally oriented towards preparation more than combat. They would probably include a lot of Shaman/Voodoo-type ideas too. Likely some crossover with the "discrete spells" guy in concept but probably different mechanics.
I think the spell list would be a hell of a lot shorter than D&D and none of the classes would share stuff on it. It's possible rituals might be shared between "discrete" and "New Age" casters.
Druid is an interesting question because it is a fairly strong and recurring archetype which doesn't exactly map to any of these. It might come in as a class of it's own.
Classes I think we definitely wouldn't see, even in conceptual equivalents with different names:
1) Cleric - It was essentially created in a freak incident from the intersection of a need to counter an OP PC and two archetypes (one of which is deeply obscure).
2) Paladin - I don't anticipate people will see any need to give magical powers to knight-types that can't be done with magic items.
3) Thief/Rogue - Crosses over hard with Swashbucklers in fiction, and virtually all of these types in popular fiction by 2020-ish will be competent, even superior combatants, so there will be no need for them. It's unlikely traps and so on will loom as large either, given a later creation date. We might eventually see a skill-monkey class but it won't be linked to backstabbing/stealth.
4) Bard - RIP, I think that's another really unlikely one. We might eventually see a class with "singing magic", but I think they'd be much more of a conventional class than the weird thing Bards have often been. Even heavily D&D-influenced games often drop Bard or have no idea what to really do with it.
7) Monk - Martial arts class would likely be Street Fighter-ish. The Monk only exists because Shaolin Monks were huge in the 1970s and still kinda big in the 1980s.
