One thing I may need to consider is the difference between contributing in combat and contributing out of combat.
I suppose I had intended "the 'math' for 'out of combat' challenges" to be, "what portion of these level-appropriate scenarios can you contribute to?", as well as "how much did you contribute?".
Of course, this runs into the same problem of, "how much does BFC contribute?"; that is, measuring the relative value of different vectors beyond "the direct approach" and "numbers".
Suppose a noble wants to embarrass the PCs in court. The Bard could use their silver tongue to do damage control. The Fighter could get insulted, and challenge the noble to a duel. The Barbarian could use his grapple bonus and "strange customs" class feature to give the noble a big hug whenever he opens his mouth. The precog could see this coming, and tell the Assassin, who, you know, solves the problem. The Cleric of Tzeentch could make the noble throw up in his mouth, making his words carry less weight. The Wizard could… probably do something.
So, several things.
There's not necessarily a hard line between combat and noncombat abilities. There certainly isn't a hard line between combat and noncombat challenges.
I had little trickle coming up with an answer for almost any conceptual "class". However, as rather bad news for the purposes of this thread, those answers were almost exclusively ways to
solo the challenge. Giving characters these tools doesn't let them *participate* in all challenges.
Getting from point A to point B
Spoiler: Seven Deadly Sins
Show
In the anime "Seven Deadly Sins", the Wizard Merlin could just teleport the party from place to place. But she usually doesn't.
Usually, Meliodus provides transportation via his mobile tavern. It's slower, but it has its advantages: they can bring stuff, they can sleep indoors in comfy beds, Merlin doesn't waste mana, they can travel to warded areas, rumors come to them, they earn money while making Gather Information checks. But, most relevant of all, everyone can contribute to the tavern. Ban can cook. Elizabeth (and Gowler and once even Merlin) can wait tables. Diane can act as a billboard / advertise to try to get customers to come. Merlin can shrink Diane so that she fits inside & doesn't have to walk. I'm not sure how King or Escanor contribute.
Point of that rambling SPOILER is, there are ways to solve noncombat problems that provide the opportunity for other PCs to contribute. Seven Deadly Sins manages to highlight this fairly well, IMO, providing both "everyone contributes" and "one character can solo" the challenge of "getting from point A to point B".
So, I suppose my question is, to what extent does that matter in an RPG? If it does matter, in what ways should the system facilitate that? Or is noncombat "contribute vs solo" something that should/does exist solely at the "role-playing" layer, not the mechanics layer?