Constructing puzzles
Puzzle elements have to be well thought out.
We'd much prefer a game that expected you to go through a castle gate puzzle, rather than just go through the gate.
But we have to construct the puzzle well.
We'll put a kid hangin' around at the gate who tells you:- "the last person who went in muttered something about a book."
Remember:- It's your RPG so just make it so you like it, and therefore other people like-you will also like it.