Amazon MGM Studios Is Developing a Film of 'The Summer of Broken Rules'
Amazon MGM Studios is developing a film adaptation of The Summer of Broken Rules, the young adult romance novel by K.L. Walther. Deadline reported the project exclusively on 21 October 2026.
The film comes from two production companies. Sophia Stallone's newly launched Common Era Projects is one, and she will produce for Common Era. Sylvester Stallone's Balboa Productions is the other, with Sylvester Stallone and D. Matt Geller producing for Balboa. Balboa renewed its first-look film and television deal with Amazon MGM Studios at the start of 2026. A first-look deal gives a studio the first chance to buy a producer's new projects.
The screenplay will be written by Lauren Hynek and Elizabeth Martin. Their credits include Disney's 2020 Mulan and Netflix's animated feature Spellbound. Both are set to adapt the book, according to Deadline. No deal terms or start dates have been announced.
The novel came out in May 2021 from Sourcebooks Fire and reached number one on both the New York Times and USA Today bestseller lists. It has been sold into 19 territories, meaning 19 countries or regions where a publisher has bought the right to release it. The story follows Meredith Fox. Eighteen months before the book opens, her sister Claire died. Meredith joins her family's game of assassin on Martha's Vineyard during a wedding week, where players try to "eliminate" one another. There she forms an alliance with a groomsman.
Sophia Stallone has a second project in the works with the same partners. She is also producing the MGM Television series Bourbon & Lies, based on Victoria Wilder's books, through Callisto Media alongside Balboa.
In an Instagram post from October 2025, the company said Sophia Stallone had first brought the property to Balboa for television. The same post said her announcement continued her focus on female-driven projects. The film version is now the route being reported.
For readers who have not followed Hollywood deals before, the timing is simple. A book can sell well, find a buyer, and still wait years before a screenplay is finished. A film being "in development" means the rights and writers are in place, but no cameras are rolling and no release date has been set.
