@Pale Wolf
You're coming up with a lot of really interesting ideas, but one thing that's jumping out at me is usability concerns. I don't know what your table experience is, but I have never ever encountered fatigue rules in any game I have played or run- they just don't come up.
Extrapolating, basically any kind of 'Thing' you have to expect the players to track relies on them either already having established good player habits, or an ST that is doing the tracking for them. Exalted already has a huge complexity overhead, so be aware of that going forward.
While I can't claim the credit for the ideas - this was MJ12's idea initially, I just remembered it -I totally agree with this, any fatigue/encumbrance rules would need to be written pretty elegantly to slot them into the basic rules without having to track extra stuff.
That elegance may not even be
possible with the existing rules (though Ex3's initiative system lends itself a lot closer to it than Ex2's health levels which required fatigue to be an entirely separate thing to track that never was tracked) - I am basically assuming as a given right now that they're written with that necessary flair, since we're spitballing high concept stuff right now, but actually doing that writing is non-trivial.
I know roughly how I'd slot it into 'how Pale Wolf would do an Exalted combat engine' (I've poked at an init combat engine for Ex2 though I've never really done much dedicated design work and it's largely concepts floating around in my head right now, and literally a one-sentence introduction in a Wordpad document that has yet to have any of those concepts written in it), but fitting it into the
existing rules (or writing up the sum total of how I'd do such a combat engine with those rules included) is a project I haven't got the time to poke at in any kind of depth for a couple days.
Part of this is that fatigue generally has a lack of granularity to how it's handled classically, but you actually have encountered fatigue rules. D&D hit points? Those are straight-up 'how much energy and initiative you have', as depleted by defending yourself against getting sworded in the face.
Ex3 initiative can plausibly be rejiggered to this end - or at least, Init is where I'd be looking first if I wanted to implement fatigue rules in Ex3.
Ex2 actually does have fatigue rulesthough as you note they're never actually
used.
I would largely avoid that sort of mechanic, because it just flat-out doesn't mesh with existing systems, and lacks granularity. It either doesn't happen, or it happens and you immediately want to fix it - it's less of a 'consideration' and more of a minor disaster to be avoided. Physical energy management isn't an event, it's a constant consideration, so I would want to mesh it into the blob of considerations a fighter has to manage that is Initiative. Like, we've already shovelled distance management, balance, control of the centerline, and tempo (etc etc etc) into Initiative, on a concept level there's no particular reason that minor tiredness and 'ack I've fenced for an hour straight my arms are noodles' (seriously try to avoid doing this, arms are not delicious noodles) can't fall under that.
And what Initiative (or D&D hit points) gives us as a vector is precisely the two things existing fatigue mechanics lack: Enough granularity to come into play rather than being an event that can be avoided and that you really rather would, and meshing into our standard package of 'things we already consider' while playing the game.
Like, I flat-out don't think I could do this in Ex2 without 'adding another thing to track', the granular hooks to do it just don't exist and would need to be
created. If I were using Ex2 as-is the best bet would be to massively harshen up fatigue rules (something like forcing that fatigue roll on every Action to toss out a highballed ballpark - something big enough to make it a thing that people constantly have to worry about and factor into their decision-making so if they lack the Sta/Resistance to handle their desired armour they have to tune their desires downwards), but as you note, that just adds management overhead to an already-high-overhead system (my Exalted group absolutely hated managing Ex2's tick system, which I still find weird because
I was the one handling it even when not the ST and I never had issues with it...).
Now it's uh 2 AM so I'm gonna have to scoot on you but I'll come back to this later with a bit more crunch if I can - like I said, while I think it's the
best solution, it works best from the ground up, and slotting it into Ex3 is at
best going to involve revamping the entire combat equipment paradigm, so it's a real big project even if you're not doing it from the ground up.
If you want something quick and easily slotted in without changing the underlying systems, Kuciwalker or Bursting Eagerness Soul have the best solutions I've yet seen - either 'pick an attribute, that is now your Hitting Things attribute' or 'use the average to calculate to-hit and distinguish whether you're Strong, Agile, or Balanced by stunts and fluff and relevant charms'.
