1. First, the casting process for Percy Jackson and the Olympians was "extensive." There was an open casting call, and they saw "thousands and thousands of tapes" of "great young actors." Rick Riordan explained that they went into it "without any sort of guidelines or restrictions" on what type of actors they were looking for. He just wanted to make sure they embodied his characters perfectly.

2. When Walker began acting, his dad apparently asked him what his dream role would be, and he said Percy Jackson. He's a big fan of the books and, according to Rick, he's read the series "seven times now."

Rick recalled, "Walker really is a fan of the books. He had been reading them since he was a little guy. He told me recently that since I'd seem him last, he's read the book series again. He's a super fan. One of the first questions his dad asked him when he got into acting apparently was, 'What do you want to do? Who do you want to be?' And the first thing he said was, 'I want to be Percy Jackson.' And that never wavered. So, he came into it with that kind of energy and commitment."

3. Walker was cast as Percy Jackson before The Adam Project was released in 2022, where he portrays a younger version of Ryan Reynolds's character.

Rick said, "We were aware that Walker was doing that. We knew that he had done other work. But, we had not seen The Adam Project or anything else prior. All that did, when we saw The Adam Project, was just confirm that we'd made the right call."

4. Walker, Leah, and Aryan did chemistry tests with each other before their casting was finalized. Rick said it was important that they found three young actors who you really believed could become best friends and would do anything for each other.

5. When it came to the incredible adult actors that appear throughout Season 1, like Megan Mullally, Jason Mantzoukas, Glynn Turman, Lin-Manuel Miranda, Toby Stephens, Lance Reddick, and more, Rick explained it was similar to casting the young actors: There were no preconceived ideas for who should play each role, but rather looking for the actors who brought the characters to life the best.

6. One of the most important things for the Percy Jackson writers for the first episode was making sure Percy and Sally's relationship had time to be established so the audience felt how monumental the loss of Sally is for Percy. "She's a mother figure for so many fans of the series. So we needed to honor that," Rick explained.

7. Rick didn't know that Olivia Rodrigo was a fan of the Percy Jackson books prior to her song "Logical" being featured in Episode 1 when Sally is sitting in the rain. But, he's since found out she's a fan, and he called it "a great honor."
 
Speaking about the incredible "Logical" needle drop in Episode 1, Rick said, "I can't take any credit for the music selections. We have a whole team that does that. That's not my forte, and I wouldn't know where to start. I wasn't aware that they were going to pick that song. But, I'm so glad they did. Those are the kind of things that even surprise me. It's also a tribute to the way that a television show is put together. That it's not just my vision. It is a team effort, a team sport, and you have to let everyone else who's involved do what they're best at and bring their artistic vision to it as well."

8. Throughout Season 1, the writers made sure to thread in little hints about future characters and storylines that Percy Jackson book fans will pick up on, like Sally seemingly making a reference to Nico di Angelo in Episode 1 and Grover talking about Pan in Episode 4.

Rick explained, "That was the advantage of having the books as a guideline and as a blueprint because, obviously, I know the five book arc, and writers in the room also were familiar with it and knew where we are potentially going. So we had a roadmap that was very clear. Even though we might take different stops here or there or pay more attention to one scene than another scene, we all had the final goal in mind. If, god willing, we get to do five seasons and show the entire Percy Jackson story, we were able to make sure that we had seeded in those things in the narrative that would pay off in later seasons. It was very satisfying to be able to do that. I'm a plotter. I like a good well-constructed story. So it was nice to be able to follow the books in that way."

9. Rick considers Episode 2 "one of the most challenging" to work on because they had to cover so much ground, in terms of introducing Camp Half-Blood, a lot of new characters, the quest, and more.

10. The level of detail that went into each cabin at Camp Half-Blood was extensive. While you can't see everything while watching the episode, Rick loved that in the Hermes cabin, "There was a Mythomagic card game spread out on one of the bunks. There was graffiti carved into the side of the bunk beds."