Ovinomancer
No flips for you!
Yeah, let's get back to it:
During wilderness exploration, the party stumbles upon a grove of standing stones with weathered runes upon them, the caretakers having long abandoned the site. No one knows who they were, or what they were doing. But now one of the PCs harkens back to wandering the woods behind the family farm... "I approach one of the standing stones to examine, visually at first, the runes and compare them against what I remember of the stones behind our family farm where the green robed humanoids chanted but always kept their distance when we wandered nearby."
An INT ability check seems appropriate for a DM to call, assuming a meaningful consequence of failure might follow.
Which of the 5 INT skills (or even other skills, if you allow variant Skills with Different Abilities) might you let a player invoke in response to being asked to roll?
What might be a meaningful consequence of failure here?
I have some ideas on both, but wonder what others might say. Assumption here is following a goal-and-approach style.
In effect, this scenario is presenting a fiction to the players with no information about what's expected or what's possible and asking them to either ask you questions about it to find out or do things blindly. This is a poor formulation from a number of angles, especially since you establish that even the DM doesn't know what they stone are or what they do. We have a vague situation that we're asking the players to negotiate. In other games, like a PbtA game, this would be okay, because the players have a lot of ways to introduce new fiction and the mechanics of those systems work well with that. But, that's lacking in 5e. Still, that's essentially what you have the player's ask do -- create new fiction.
The player's declaration is actually both complex and just asking the DM to narrate more. It's complex in that it has a buried proposition to create new fictions -- that these stones are like the stones back home. This is problematical in 5e because there's no mechanical way to do this and, in effect, the player is asking the DM to add this to the game. The adjudication of this is DM whim. So, once we've negotiated past the part where the DM decides if it's permissible for these stones to be like the ones back home, we get to the basic part where the player is now asking the DM to narrate to the player the fiction of these stones, which are now like back home, that the DM elected NOT to do prior to this (didn't know, didn't want to say, eh). The premise of the question is that the DM now decides that receiving this narration is uncertain, and has a cost for failure, and so calls for a check. Only, this check is difficult to parse because we've missed that it is just an ask for more DM narration and that there's nothing at risk here except that DM deciding that these stones aren't like back home, but, again, 5e lacks a strong mechanical use case for this kind of determination.
So, essentially, this entire though experiment boils down to the DM failing to preset a complete scene, forcing the players to ask both for new fiction and for the DM to narrate the scene more, This leads to confusion because it's assumed that the player's ask should be gated behind a check. We're asked to identify a possible failure case for this check, which is precisely backwards -- you should know this before asking for the check.
I see no check necessary here to ask the DM if the player's backstory can please be relevant to the not-fully-developed scene presented -- this is entirely up to the DM.