Turning a beloved book into a movie or TV show is always a tricky balancing act. The goal is to stay loyal to the novel, while making any changes necessary to effectively translate the story from page to screen. Big Little Lies, based on the 2014 book of the same name by Liane Moriarty, has done a fantastic job developing the page-turner into a binge-worthy limited HBO series. But as readers of the book well know, there are a decent amount of changes from the source material. Some are minor: the setting has shifted from a seaside town in Australia to Monterey, California; Madeline (Reese Witherspoon) also has a young son in the book; and the children are in kindergarten as opposed to first grade. The two most significant changes from the book, though, are fascinating and meaningful choices on the showrunners' part.
First, there's Madeline's affair with Joseph, the director of the Avenue Q production she's helping produce. In the book, there is no mention of her being unfaithful to her husband Ed (Adam Scott), whereas in the show, Madeline and Joseph rekindle a previous affair. Joseph even wants to leave his wife for Madeline.
Why the change? Madeline's character was just too good in the book, and needed a salacious secret of her own to deal with while meddling in everyone else's drama: a big little lie. “I didn’t have anything to play but perfection, and I just think those people who are perfect [are] all full of shit,” Witherspoon, who secured the book rights executive produced the show, told Variety in February. “[The change] mainly came out of me not having anything to really put my teeth into. I think there’s something fascinating about a person who projects perfection or is very judgmental of others who is clearly just swimming in their own discontent.” Flawed characters simply make for more entertaining TV.
The other important alteration is intended to have the opposite effect — to make a very unlikable character more sympathetic. Perry (Alexander Skarsgard) attends therapy with Celeste (Nicole Kidman) in the show‚ until she tries out a solo session while he's out of town. But in the book, Celeste sees the therapist alone from the get-go. Having Perry participate in therapy makes him seem like a better guy: he's a domestic abuser, yes, but he knows he has a problem and is willing to work on it. It indicates he knows his behavior is unacceptable and wants to change. Celeste and Perry seem like more of a team. Plus, the tense dynamic of the therapy sessions is riveting, as is watching the pair negotiate in the moment how much truth about their marriage they want to share with the counselor.
While there are undoubtedly some unhappy readers who think those two changes lessen the characters or the story, I think these particular character developments were an intelligent move on the showrunners' part. They make the story more complex and the characters more multidimensional, rather than simplifying things. And in a show like Big Little Lies where everyone has a dark side and everyone is suspect, that works.