With a +5 CON bonus, plus +2 from Remarkable Athlete, the 15th level fighter can make that check on a natural 20. That's the thinnest notion of feasible possible. I don't look at 1 in 20 chances as examples of significant martial prowess.Sure there are... DC 27 and above challenges.
For me, this drives home my point - a system which is first fiction-driven (is this feasible for this character, given the fiction) and then, if the answer is yes, has a mechanical procedure for assigning a DC (look up the DC-by-level chart), opens the door to high-powered non-combat martial endeavour.
A system which assigns DCs independent of the fictional circumstance that calls forth the need for it, and that in that assignment has to simultaneously manage what is feasible for both 1st and 15th level PCs, and does so in a context where the gap between the 1st level and 15th level bonus is in the neighbourhood of 3 pips on a 20-sided die, is going to struggle to produce the same outcome.
I don't know how the old Marvel Super Heroes game handled this issue. MHRP/Cortex+ Heroic handles it the same way as 4e - first use the fiction to establishe what is feasible, then follow the appropriate mechanical procedure to determine success or failure. DC Heroes used a system closer to the 5e one in its basic structure, but extreme variations in bonuses between street-level heroes and demigods. (And I can still remember the title of Jeff Grubb's Dragon Magazine review of that systme: "Done Cleverly, but Definitely Complex".)
For that I think you will need Runequest. I don't know any version of D&D that takes that approach to fire.Personally I would prefer the narrative of the high level fighter subduing the fiery elemental spirit powering the forge so that the artificers can safely work the magic hammer.
That seems true but orthogonal. The fighter in my actual play example is not very competent at acrobatics or chess or diplomatic negotiations. But he is an extremely tough dwarf - the toughest one around - and so seems like he should be rather competent at tests of endurance.I think that it is fine for a character to have a weakness where they really are not competent.
Which is my whole point. My only quibble with this is that when you say it is within the genre of "D&D" performance, I would respond that - given my actual play experience was from a D&D game - it is a particular take on "D&D" performance (one that I would particularly associate with 2nd ed AD&D).Again, it's a genre preference. 5E covers four tiers of play, that offer a spread: but it is within a certain genre, of "D&D" performance at different levels. So, no, high level fighters aren't going to put their hands in a magic forge, maybe with magic gloves.