I've read the rule book (and searched the forum) about cards being ''in play'', but it's still not clear to me if an active location is considered to be in play or not; if not, it means that only locations in the staging area are considered to be in play?

Thanks!

I see where your question is from. In the back of the rule book it notes what constitutes being "in play" and "out of play" and both sections omit any mention of the phrase "active location".

However, I think it is pretty clear that the intent is that the active location is in play. I found a bit of text in the core set rule book that supports this is the case, even if it is a bit weak.

If a location ever has as many progress tokens as it has quest points, that location is considered explored and is discarded from play.

It would be impossible to have the active location be "discarded from play" if it was already out of play so it leads me to believe that active locations (as well as locations in the staging area) are in play.

Yep, makes a lot of sense. Thanks!!!