Maybe you’re thinking about writing a screenplay, but don’t know where to start. Or maybe you’re interested in following in the footsteps of writer-directors such as Mindy Kaling or Jordan Peele.

As a genre, horror movies are not known for scintillating dialogue. That said, while no one expects Beckett from a popcorn thriller, most of us do cling foolishly to the hope that at some point during ...