Right off the bat, fans of the source material will likely recognize that IT is not a 1:1 adaptation of Stephen King’s source material.
It goes to show that something doesn’t have to be exactly like the book that inspired it to resonate with audiences.
Adapting a well-known and popular book almost always represents a distinct challenge for a filmmaker, but Andy Muschietti made some fantastic changes to the IT story that keep it timeless and personal, while also saving some strong storylines for the inevitable IT 2.
Several infamous sequences (such as the orgy scene) have been cut from the film, the subplot involving The Losers Club as adults has been saved for the sequel and the monsters that Pennywise manifests have changed from pop culture icons to more personal phobias.