The fact that there is not more then there is does not mean that there is not what there is.
I'm not saying that Fighter abilities need some kind of special explanation. I'm saying that they need a basic level of explanation equal to what other classes that already have.
Fighters already have the basic explanation you require. Because fundamentally the way the explanations all break down is the same.
Wizard: I learn to read books good
Sorcerer: My blood good
Bard: I learn do music good
Fighter: I learn to fight good
Basic explanation accomplished.
As I said we previously we have a very broad understanding understanding of how wizards, sorcerers, bards etc bend reality.
All I'm saying is do the same for Fighters. Are they like Sorcerers and their ability is inborn - do they harness something from a magical bloodline like Bloodragers in Pathfinder? Do they learn their abilities from special mystical schools like wizards or Wuxia heroses?
Are they slowly becoming gods like the high level Fighter equivalents in the Malazan Book of the Fallen?
Are all of these possible and the player gets to choose?
We have an extremely shallow understanding of how the casters bend reality. Far far far far more shallow than anything you've proposed above for Fighters. I see no reason Fighters should be required to make such a selection, and many reasons why they shouldn't.
throw those of us who actually care about the implied setting...
So. I specifically bring up setting elements people don't care about. Your response dismisses those elements without addressing any of then at all, and I'm the one who doesnt care about the setting..cool.. Maybe the hypocrisy was unintentional?
.. of the game a we play in a bone and maybe giving Fighters something good at high level might actually stand a chance of happening at some point.
The bone has already been thrown. The explanations are already there. You just have to accept them.
In any case, I think making such decisions would inevitably make the mechanics better because they would be more meaningful.
So you would say that caster's mechanics are more meaningful as-is?
I don't know why there is so much discussion about jumping in this thread. The Fighter needs to be able to jump well to not be the only party member to have to find some complicated way across the acid pit at level 5 after everybody else used Misty Step. As I said earlier, being able to jump or perform feats of Strength doesn't really begin to cut it at level 18 if we're serious about keeping up with the wizard.
It's because it is one of the most obvious examples where Fighters are hamstrung by mundane obstacles for the full duration of their career. Even the subclass that gets a specific ability to help with this receives a bump so small as to be functionally useless In all but the edgiest of edgecases. It is this way when it doesn't have to be.
The generic ability to wield magic is not inherently stronger than just being physically strong. It's power and usefulness is entirely based on the abilities granted by the game system. The game system could also just grant similarly useful powerful abilities to physically stronger PCs. That it doesn't is the problem many of us have with it.