Make it about stone elves. Wood elves are seen in abundance. Also dark elves, high elves and such.
Of course the stone elves might have adjusted to working stone and digging, so they probably are a bit on the smaller side and maybe stocky.
And maybe they fight trolls. Probably on a market place. While minding their own business, the trolls rolled in and tried to rally up the townsfolk against our stoner elves.
The plot twist: it was the same troll again and again, wearing different disguises.
Anyway, if your rpg idea starts with a race or species as a plot device, you have nothing. The main hero or heroes being elves is not a story all by itself. You will need something to tell that is interesting. Elves being elves is boring. It is only the contrast with other beings or the utter alien concepts they would have, that make it interesting - or extra boring, as the trope of the elf is overused. Elves are the Mary Sue of the fantasy creatures.
Have them go on a quest to save their kind, because Elves are starting to suddenly grow old. You can add lore, why the elves are long lived to begin with and build on that.