As it turns out, the two-part play Harry Potter and the Cursed Child is not a wholesale departure from the storyline that ended with J.K. Rowling's seventh novel in the series over a decade ago. It's more of an extension that jumps ahead in time, and does some jumping back as well. And while it's not inconceivable that someone who has little or no memory of the movies or never read the books could still enjoy it, there are some things that non-Potterheads should probably learn or brush up on if they don't have time to screen all eight films before heading to see the show.
The Tony Award-winning play opened at The Curran in San Francisco on Sunday, marking its West Coast premiere — and you can read SFist's full review here. But the sheer length of Rowling's total work combined with the litany of character and plot details that she and playwright Jack Thorne expect audiences to remember is not inconsiderable.
So, just to help, here's a quick primer that supplements the Cliff's Notes summary of the seven books that you'll find in the Playbill when you arrive at the theater.
Hogwarts: You have to have been living under a rock not to have heard of the Hogwarts School of Witchcraft and Wizardry. Modeled loosely on the popular British trope of boarding school novels for children and young adults, Rowling's book series is anchored by the imposing school, and the trip by first-year students on the Hogwarts Express frames the opening of Cursed Child.
Notable Hogwarts faculty: You may want to remain surprised about who gets included in the new story, and that is fine. But I'd recommend scanning IMDB and familiarizing yourself with the names of the faculty members and the British actors who played them, to refresh your memory and prepare for the ample name-dropping, etc. in the play.
Sorting Hat and Houses: Harry and his friends are notably "sorted into" the House of Gryffindor, while longtime platinum-blond nemesis Draco Malfoy is part of Slytherin — the snake-associated house that dabbles in dark magic. One is chosen for a house via a magical hat, and the association with one of the four is meant to reflect one's personality, talents, and virtue in this universe.
Lord Voldemort: The evil, noseless dark wizard who hovers over all of the Harry Potter series, and who is only finally defeated in the final book. He's responsible for killing Harry's parents, orphaning him, and spends years trying to kill Harry himself.
Hermione and Ron: They're married with two kids in the new story, and some of the details behind their courtship are relevant here as well.
Ginny Weasley: Ron's little sister who in the later books becomes Harry's girlfriend.
Cedric Diggory: A popular kid at Hogwarts played by Robert Pattinson in Harry Potter the Goblet of Fire who is killed on Voldemort's orders during the Triwizard Tournament.
Dolores Umbridge: A mean-spirited bureaucrat at the Ministry of Magic, played by Imelda Staunton in the films, who later becomes High Inquisitor at Hogwarts and then, briefly, Headmistress of the school.
Muggles and Mudbloods: Terms in this world that define non pure-blood witches and wizards — all regular lay citizens are muggles, and those who are born with powers to muggle parents are "mudbloods."
Quidditch: The popular sport played at Hogwarts involving flying on broomsticks and trying to get a projectile through another team's floating rings.
Time-Turners: These devices for sending people back in time don't figure heavily in the books, though Hermione deploys one given to her by Professor McGonnagal in Harry Potter and the Prisoner of Azkaban so that she can double her class load during her third year at Hogwarts and attend more classes than time would allow. The devices were banned in later years and the remaining stock of them were rendered useless/destroyed and stored at the Ministry of Magic.
Death Eaters: The term for followers of Voldemort. In the sixth book, Harry suspects that Draco has become one.
Hagrid: A gentle half-giant who teaches at Hogwarts and is the first to tell an 11-year-old Harry that he's a wizard.
The Dursleys: Harry's muggle aunt and uncle, Petunia and Vernon, who adopt and mistreat him and make him live under the stairs until Hagrid comes to whisk him off to Hogwarts in the first book.
Bellatrix Lestrange: The dark witch character and loyal servant of Voldemort played by Helena Bonham Carter in the films.
Related: 'Harry Potter and the Cursed Child' Is a Wild Ride and Dazzling Piece of Theater