Book about three companions forced to solve puzzles to find gems

Question

A series about a king and 2 of his companions taking a quest to find some relics or gems or something. I read it in elementry school, around 2004-2008, but it could be older than that. There's a dark lord and some ultimate evil, but I don't remember many specifics. I think there was also a dragon for each gem? Not Eragon, though. It's medieval fantasy I think, like kings and knights and magic.

I do remember 1 thing that, at least I hope, would set it apart from most other books. In the book, the characters were often presented with puzzles they needed to solve. Then, after a description of the puzzle, it would have a small illustration of the puzzle layout on the page below it.

One I remember clearly - the main character is presented with 8 squares, made with sticks. Each square is made of 4 sticks, and some of the squares share sticks with the ones next to it. Inside 7 of the squares are scarabs, or beetles of some sort. The person presenting the puzzle then tells them to remove 2 sticks that aren't touching, and make it so that no scarab is released from the frame, and no square has more than 1 scarab - or something along those lines. Then it had a picture that looked like how it was described.

EDIT Thinking about it more, he may not have been a king at the start of the series. I think the main character became the king in book 1 or 2, but I may be wrong.

Answer 1

Deltora Quest, by Emily Rodda

Deltora Quest is an 15-book series divided into 3 sub-series - the 8-book Deltora Quest, 3-book Deltora Shadowlands, and 4-book Deltora Dragons.

The first series is focused on retrieving a set of 7 gemstones for a magical belt.

From Wikipedia:

The first series of Deltora Quest follows the journeys of Lief, the son of a humble blacksmith [in disguise], who, on his sixteenth birthday, sets out to fulfill his fathers quest to restore the Belt of Deltora. Joining Lief is an ex-palace guard named Barda. Along the way they meet with Jasmine: a wild girl from the Forests of Silence, who has long, black hair and emerald eyes. She can speak to trees and has two pets: a raven named Kree and a small, gray, furry creature called Filli. Their quest is to find the seven gems of the fabled Belt of Deltora: the topaz, the ruby, the opal, the lapis lazuli, the emerald, the amethyst, and the diamond. The gems each have a special power and are hidden in dangerous locations around Deltora. The three friends must face numerous perils to reach them. Once the Belt is complete and the proper descendant of the first King of Deltora, Adin, wears the belt, the evil tyranny of the Shadow Lord will be forced back to the Shadowlands. The books in this series are The Forests of Silence, The Lake of Tears, City of the Rats, The Shifting Sands, Dread Mountain, The Maze of the Beast, The Valley of the Lost, and Return to Del.

Bolding is mine, to emphasize the parts that line up with your recollections.

Many of the challenges they faced were puzzle based, and while I don't remember a stick-and-scarab puzzle specifically, it is similar in style to the types of obstacles they encountered.