Books and characters in the series were inspired by books and films. For example, the character Slappy the Dummy was inspired by the literary classic The Adventures of Pinocchio.[13] Some of Stine's ideas for the books also came from real life; Stine got the idea for the book The Haunted Mask after his son, Matt, had a Halloween mask that he had trouble getting off.[14] Stine also uses his childhood fears to help him write his books. The author said, "Luckily, I have a great memory. As I write a story, I can remember what it feels like to be afraid and panicky".[15] Stine states that he often thinks of a title to a novel first, then lets the title lead him to a story.[16]
Two common themes in the series are children triumphing over evil and children facing horrid or frightening situations and using their own wit and imagination to escape them.[17] Stine does not attempt to incorporate moral lessons into his novels, and says his books are "strictly reading motivation".[18]