Blue
Ravenous Bugblatter Beast of Traal
How do you reconcile the goal of "staying in character" with the approach of players stopping to ask the DM what their characters know about trolls?
That's perfectly in character.
If I see something I don't understand, I often think about it. I have a lot of experiences that pertain to, oh let's say IT infrastructure and science fiction. I can directly access those experiences.
If my character sees something they don't understand, I often have them think about it. They have a lot of experience that pertains to, oh let's say living in a fantastical world filled with magic and monsters. I access the DM as my interface everything in that world including what happens "off camera". The description of Intelligence Checks explicity describes it's used when I am calling on things such as education or memory - not that a check would always be needed, but as an example that this is the type of thing a player can expect from a DM.