I did once see in the shops a Tolkien trivia book that looked, from a cursory glance, to be based on the books rather than the films. Also, there are a number of board games on the market based on the books (both
The Hobbit and
LotR). Presumably, in these instances, the rights were available at a cost sufficient to make it worthwhile producing and marketing the items in question. If so, then I don't see why a quiz game based on the books alone would be out of the question.
Any budding entrepreneurs out there?