One of our most highly anticipated TV shows of the year is HBO’s Westworld (which we loved, if our review is any indication), and we’re excited as hell to keep watching the mysteries of the scientists and synthetic wild west people populating its shady streets. While the series is very much about the nature of existence and the morality in creating life—even robotic life—and then allowing or causing harm to them, it’s interesting to remember that Westworld began life as 1973 movie that was a prototype for both Jurassic Park and Halloween.

Westworld was the directorial debut of novelist and screenwriter Michael Crichton. Following the success of The Andromeda Strain—which had been based on his first novel—Crichton was getting more involved in Hollywood and wanted to direct. The studio (MGM), however, would only let him direct a science fiction film, which led to the writing of a relatively small production that would be a sci-fi premise mixed with western imagery and horror story tropes.

The film stars James Brolin as a wealthy adventure-seeker who has found a resort only for the super rich. Patrons—almost all men—can choose between three different experiences: Romanworld, Medievalworld, or Westworld. Each is a fully-immersive visual spectacle using the latest in modern technology. The patrons can pretty much do anything they want, and each world is populated by robotic minions which patrons can do anything to and the robots just take it. Brolin drags his equally rich but far less adventurous friend Richard Benjamin to Westworld and they have a grand old time, until there’s a duel with a Gunslinger robot (Yul Brynner, wearing essentially his exact costume from The Magnificent Seven). A park malfunction occurs and the Gunslinger awakens and becomes deadly, marching unfettered after our unaware heroes, killing any of the technicians who might be able to help.

The movie was a prototype of sorts for Crichton’s novel Jurassic Park, essentially a verbatim version of Ian Malcolm’s line, “When The Pirates of the Caribbean breaks down, the pirates don’t eat the tourists.” A cowboy robot takes the place of a pirate robot, but it may as well be the same. Disneyland, or places like that, seem idyllic and perfect but if there was even a little bit more danger added, it could be frightening. And a singular, unfeeling murder machine you can’t reason with that happens to look like a man is such a stark and disturbing image, and one that John Carpenter has referenced on numerous occasions as being an influence on his 1978 film Halloween and the character of Michael Myers/The Shape.

Westworld was followed in 1976 by Futureworld, a sequel that Crichton had nothing to do with and—save a brief cameo by Yul Brynner—none of the original cast appeared in, either. Peter Fonda and Blythe Danner play news reporters (print and television, respectively) who go to review the park years after the Westworld incident. $1.5 billion has been spent on safety features and now, instead of Westworld, guests can choose Futureworld as one of their experiences. Everything seems fine at first, but soon it becomes clear that the company wants to make robot duplicates of the reporters and other high-profile visitors. The goal is to clone the rich and powerful in the world to influence world events. The movie was not met with much adulation upon its release.

However, the premise was still popular enough to warrant an albeit short-lived television series, Beyond Westworld, in 1980. It followed a security chief for the nefarious corporation who has to stop an evil scientist who plans to use robots to take over the world. Only five episodes were produced before cancellation and only three actually aired.

So, in many ways, HBO’s Westworld series is very much in keeping with the rest of the franchise on a lot of levels. Not just robotics going haywire, but a clandestine research company being behind everything, with aims very different from merely providing rich people with interactive amusements. However, far more than any of the previous entries, the HBO series gives the robots a voice, and makes them and their “life” much of the focus. The Gunslinger (Ed Harris) is also an upending of expectations based on Yul Brynner’s same-named character. (I won’t spoil the nature of this upending for those who haven’t watched yet.)

The original Westworld is available for rent on Amazon Prime, YouTube, iTunes, and a few other online rental places; Futureworld is available for free with a Hulu subscription and Beyond Westworld is available on DVD and (ahem) maybe other means as well. These are not integral to the enjoyment of HBO’s Westworld but will provide some interesting context, if you’re into that sort of thing.

What did you think of Westworld‘s first episode? Let us know in the comments below!

Here’s some more shows we’re excited about this fall!

Image: MGM

Kyle Anderson is the Associate Editor for Nerdist. You can find his film and TV reviews here. Follow him on Twitter!