For how to handle specific maneuvers. Instead of making a list of powers/abilities, why not just make a point buy system for players and DMs to create their own powers? You can use page 42 of the 4E DMG as a starting point. Mutants and Masterminds and GURPS could also be looked into. Or you could give the warrior stunt dice/tokens/resources that empower improvised actions. If you did that, you should include player and DM guides on how to negotiate unique actions/stunts.
It's a good question. My approach is much more focused on design elegance and smoothness of play at the table. It's intended to be swapped out for the 5e fighter for groups who feel that the fighter's design leaves something wanting. So, for my purposes, a GURPS/M&M-esque point-buy power creation would be just as undesirable as a glut of 4e-style powers – because it's inelegant, slow, and likely requires more mental attention than most players want to devote when the action is running hot.
Now, as for "stunt dice" that empower improvised actions, that sounds a lot like the Superiority Dice of the Battle Master Fighter. That's already there as an option for players who like resource tracking for their fighters. There are plenty of fighter homebrews out there that expound on the Superiority Dice concept & make it a core class feature. I consider "stunt dice" part of the "OK enough" design behind the fighter because it drops the narrative ball. WHY can I only parry up to 4 times in a combat and have that mean something mechanically? There's no narrative reason.
When you get into limited-use abilities, you really press up against that narrative barrier. Spellcasting has "spell energy", but nowhere in the history of D&D (until 4e) was the fighter associated with limited-use abilities. By limited use I mean X/day or X/rest. HOWEVER, it is possible to design narratively meaningful limitations on abilities without resorting to X/day or X/rest – see my design of
Parry for an example.
[SECTION]
Parry. At 1st level, when you are hit with a melee attack, you can parry the blow using your Reaction so long as you are wielding a weapon or shield. In order to parry, make an attack roll. If your roll equals or exceeds the attacker’s roll, reduce the damage of the attack by an amount equal to 1d10 + your warrior level. If you take damage from an attack you only partially managed to parry, your guard is broken and you cannot use Parry again until using an action to catch your breath and reestablish your guard.[/SECTION]
There's also legacy reasons to include differentiation of abilities by weapon, which date back to the origins of the game. And it makes sense. The fighter is the one we strongly associate with weapon specialization. That's its DNA. I chose to reach into BD&D and 4e for inspiration because those were the editions where differentiation by weapon was most interesting (i.e. more than +# attack, +# damage for specialization).
I don't think it's anymore limiting to say "fighters who want to set a weapon against a charge need to fight with a spear" than it is to say "wizards who want to knock enemies backward need to prepare
thunderwave." It's part of the D&D DNA. It's a way to differentiate characters.
And making a trap seems more of a Rouge/Ranger thing anyway. Though I do admit fighting T-Rexes isn't something we don't think enough about in general. Then again, I don't think we think about what high level fighting looks like. A T-Rex is just a CR 8. It wouldn't be unfair to throw 4+ T-Rexes at a level 15 party. It's something to consider at the very least.
