In the GURPS ecosystem, this would usually be handled by a Reaction Roll or an Influence Roll, with various bonuses or penalties for character features (e.g., reputation, appearance, charisma, etc.) and potentially for clever (or not) roleplaying. An especially good roll (the equivalent of a critical success) might mean that the NPC provides more assistance than expected. I've often used that to lead to gifts or loans or other unexpected perks.
In terms of the Aragorn scene, I would play that out with an initial Reaction Roll with no reputation bonus. When Aragorn chooses to reveal his heritage, I would roll again with different modifiers. (Or Aragorn's player might bring one of their skills to play in an Influence Roll, like Diplomacy, Psychology, or Intimidation.)
I have also occasionally had potential patrons in the game whose reactions would be influenced by a series of skill rolls rather than a single check. One war chieftain challenged the PCs at a banquet with a simple request: "Impress me!" Each PC then had an opportunity to attempt a feat that they thought might seem impressive to him. There were a variety of rolls involved as some of the more social characters attempted to size him up and bookish sorts tried to recall any knowledge they might have about his reputation. Successes on these rolls would act as complementary skills, increasing the likelihood of a good success. My recollection is that the party as a whole did pretty well, but the wizard flubbed his rolls terribly and was mocked mercilessly by the chieftain, creating complications later in the adventure.
In terms of the Aragorn scene, I would play that out with an initial Reaction Roll with no reputation bonus. When Aragorn chooses to reveal his heritage, I would roll again with different modifiers. (Or Aragorn's player might bring one of their skills to play in an Influence Roll, like Diplomacy, Psychology, or Intimidation.)
I have also occasionally had potential patrons in the game whose reactions would be influenced by a series of skill rolls rather than a single check. One war chieftain challenged the PCs at a banquet with a simple request: "Impress me!" Each PC then had an opportunity to attempt a feat that they thought might seem impressive to him. There were a variety of rolls involved as some of the more social characters attempted to size him up and bookish sorts tried to recall any knowledge they might have about his reputation. Successes on these rolls would act as complementary skills, increasing the likelihood of a good success. My recollection is that the party as a whole did pretty well, but the wizard flubbed his rolls terribly and was mocked mercilessly by the chieftain, creating complications later in the adventure.