Having to analyze the backstory of "Dash and Lily," authors David Levithan and Rachel Cohn wrote and published "Dash and Lily's Book of Dares" in 2010. Additionally, Levithan and Cohn also wrote the novels turned movies "Nick & Norah's Infinite Playlist" and "Naomi and Ely's No Kiss List."
According to the backstory, the show's title (and book) alludes to the relationship between the authors Dashiell Hammett and Lillian Hellman.
In Episode 2, Lily mentions her "Mrs. Basil E," possibly a reference to the book"From the Mixed-Up Files of Mrs. Basil E. Frankweiler," a novel by E. L. Konigsburg. The book follows siblings Claudia and Jamie Kincaid as they run away from home to the Metropolitan Museum of Art in New York City, published in 1967.
Lena Dunham was once attached to write and direct the adaptation.