Although it became a huge part of the mythology in subsequent films, Jamie Lee Curtis' Laurie Strode and Michael Myers were not siblings in the original 1978 Halloween. That twist actually occurred in Halloween II and apparently in part came about from John Carpenter being inebriated. The writer/director of the first Halloween and co-writer of Halloween II spoke about what led to the twist and his disdain for it, saying:
Well, despite his general brilliance, John Carpenter is far from the only person in human history to have come up with a bad idea while in an altered mental state. It sounds like he and co-writer Debra Hill were under the gun with a bad case of writer's block and just sort of had to come up with something, so with the aid of a little liquid inspiration, they forced that connection with the sibling twist.
The first Halloween is considered to be such a perfect horror film and the birth of the slasher sub-genre that it really didn't need anything changed or added. But as John Carpenter told The Daily Beast, for the television airing of the film, they needed to extend its runtime, and that necessitated adding more material, which is something they struggled with.
So while filming Halloween II, and with a little help from alcohol and desperation, they added the sister twist to the extended TV version of Halloween. That twist was then incorporated it into Halloween II and carried on throughout the series through decades of sequels and reboots.
Obviously looking back, John Carpenter isn't happy about the twist, and you can kind of see why. He didn't even want sequels in the first place, and a bad story choice wound up becoming a major part of them.
Forcing familial connections when done well can be awesome and shocking (The Empire Strikes Back), but it is so overdone, and making everything connected in that way is often a case of bad or lazy writing. In this instance, it makes Michael Myers a killer with a purpose versus just a force of nature, killing at random with no rhyme or reason.
Now, almost 40 years since the sibling twist was introduced, the hangover of that drunken decision is finally wearing off. David Gordon Green's new Halloween retcons the franchise's continuity, removing everything but the original film, including Halloween II. And since the Halloween TV extended version is not canon, that means that Laurie Strode and Michael Myers are no longer siblings.
The trailer for Halloween even references the sibling connection as "something people made up," letting audiences know that the slate has been wiped clean.
You can see how it all plays out when Halloween hits theaters this Friday, October 19. Check out our premiere guide to plan out all the movies you should see this fall, and for all the latest in drunken decisions, stay tuned to CinemaBlend.