Marcy Campbell is the author of the debut middle grade book, Rule of Threes. This book handles several sensitive topics — including marital infidelity and substance abuse — with remarkable thoughtfulness. I loved talking to Marcy in this interview about her writing process, writing about hard topics, and her love for design. Enjoy!
Chronicle Books is giving away a copy of Rule of Threes at the end of this post if you’d like to enter the giveaway.

Hi Marcy! I’m happy to be chatting with you about your debut middle grade novel, Rule of Threes, which I enjoyed. What a tricky subject to write about: parental infidelity and a new step sibling. Why did you decide to write a book with this premise?
Happy to be here, and so glad you enjoyed the book!
I actually started with the design angle, not the infidelity and newfound sibling. I knew my main character was going to have an interest in decorating, and I was listing a bunch of design “rules” one day, when the “rule of threes” came up, which refers to groupings of odd-numbered items being more pleasing to the eye than even-numbered groupings.
For my main character, Maggie, the number is also important because she has a best friend (and business partner) trio and a family of three. I was thinking about how those groups could be disrupted and landed on the “stranger comes to town” storytelling trope. In Maggie’s case, the stranger is a half-brother she never knew she had.
After he arrives, the parental infidelity comes out into the open and must be dealt with, especially by Maggie, who is learning about all this for the first time. As for why to include it, it’s something kids deal with that often isn’t talked about. Families are configured and reconfigured in many different ways.
I loved seeing Maggie’s flair for design and the way she uses it to cope with feeling out of the loop and not in control of her family situation. Are you a fan of design? Do you have any coping mechanisms like Maggie has with design?
Absolutely! I’ve always loved decorating and DIY, even from the time I was a kid (one of my first jobs was at my aunt’s Hallmark-type store, and she let me design the window displays). I typically have a stack of decorating magazines around when I want to do some mindless reading. I actually turned a bedroom closet into my office during the writing of Rule of Threes! Since Maggie had a big design project in the book, I thought I should, too! Painting rooms, refinishing furniture, etc., I find really calming, and it helps me generate new writing ideas when I’m doing something completely different and can let my mind wander. A good long walk, or pulling weeds in the garden, will work, too!

Maggie and her friends have several challenges in their relationship, but one of them is Rakell’s interesting name change and Maggie’s refusal to call her “Rakell.” I’m so curious as to what inspired that narrative arc.
Rakell is developing different interests from Maggie and Olive as they begin middle school, and Maggie doesn’t especially like it. Rakell wants to dress in a more grown-up way. She’s the first to have a boyfriend. I saw her wanting to change her name ever so slightly (from Rachel to Rakell), as a way to assert her independence. It’s also a test for Maggie who thinks, on some subconscious level, that if she calls her by the old name and doesn’t acknowledge anything changing with their friendship, then maybe it won’t actually have to change. Of course, eventually, they do have to figure out a new plan for their friendship going forward.
I really liked Tony! He’s such a good kid and I loved the dynamic between him and Maggie. Do you have siblings? Did your relationship with them in any way inspire Maggie and Tony’s dynamic?
I have four siblings, but they are all quite a bit older than me (the oldest was in college when I was born), so in many ways it often seemed like I was an only child. I would say Maggie and Tony’s relationship was inspired more by my own two children, who are 12 and 14. They have a close relationship, but very different personalities, and certainly manage to get on each other’s nerves, as all siblings do, but they are also very sweet to each other when they want to be!
Maggie’s grandmother is struggling with dementia. That’s one topic I wish more middle grade books covered. Are there any topics you would love to see tackled more often in middle grade literature?
It seems like any topic I can think of is covered in middle grade books these days. It’s really wonderful that kids can see their lives and all the challenges they might be going through reflected in books. I was just talking about this with my neighbors, who are in their 70s. They said if you look at the books from when they were young, you would have thought “everything was perfect and nobody ever had a problem.” I’m so glad that’s changed. We can’t address challenges if we deny they exist.
Tony’s mother is dealing with opioid addiction and I was a bit nervous about how you would portray those challenges, especially with that final scene when Maggie and Tony have to work together. I think you handled it perfectly and sensitively. Did you have concerns about covering this theme?
Thank you! And, yes, I was a little worried about it, but opioid addiction affects so many families, that I wanted to include it. Before I started writing Rule of Threes, I read an adult nonfiction book about the opioid epidemic and how it hit Ohio (where I live) really hard. I thought it made sense for my story that Tony’s mom’s addiction was the reason he had to come to live with his dad. Without giving away too much about my book’s climax, I remember wondering if it would be too intense, but my own kids approved of it, and my agent and editor didn’t see any problem. Kids are often able to handle more than we give them credit for, in life and in books!
Which middle grade books have you read and loved recently?
Echo Mountain by Lauren Wolk is a recent read that’s really stuck with me. The writing is absolutely gorgeous, the plot is riveting, and I love a book with strong female characters (and a few great dogs is a nice bonus).
Are there any forthcoming projects you can tell us about?
I have a picture book coming this September from Little, Brown. It’s called Something Good and is illustrated by Corinna Luyken (Corinna illustrated my first picture book as well, Adrian Simcox Does NOT Have a Horse). Something Good is about a school community struggling with the aftermath of a bad-something being written on a bathroom wall and how they come together to heal. I have a couple additional picture books scheduled for publication in the coming years and am working on my second middle-grade novel that I hope to finish this summer. I don’t like to give too much away while I’m still drafting, so I’ll just say that novel is about happiness and that I’m having a blast writing it!
Thanks for your time, Marcy!
You’re welcome! Thank you for chatting with me.
Enter to win a copy of Rule of Threes! This giveaway is open internationally.
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Meet Marcy Campbell

Marcy Campbell’s debut picture book, “Adrian Simcox Does NOT Have a Horse,” was a Junior Library Guild Selection, a Top 10 Indie Next Pick, winner of the Comstock Read Aloud Award and the Crystal Kite Award and has been translated into eight languages. “Rule of Threes” is her first novel. Upcoming books include, “Something Good” and “The More You Give.” Campbell lives in Ohio with her husband, kids and furry companions.
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This book would make a great addition to our Media Center!
Sounds like an amazing book!
Sounds like a good book, and love the cover!
I would love to share this book with my students. Thank you for the chance.