Awesome, Dear Boy: Richard Benjamin apparently welcomed the role a lot, because he always wanted to star in a Western, but never had the opportunity until then.
Deleted Scene: There is a scene added for TV where a guest in Medieval World is tortured on the rack after the robots go haywire.
Playing Against Type: As an actor Richard Benjamin is mostly known for his comedic roles, so this was a notable change of pace for him.
Recycled INSPACE: 15 years later, Michael Crichton would write his most famous story, Jurassic Park, which is also about an amusement park where the attractions go crazy and attack the guests (only this time they were cloned dinosaurs, not robots).
The sheer number of reel-to-reel computers running the resort are one obvious case.
The spreading malfunction of the Delos robots is described in terms of an infection, which the heads of Delos laugh off. The film came out only two years after what is commonly described as the first computer virus, and almost a decade before the first time one infected anything outside of the lab where it was created.
On top of that, in 1973, the Gunslinger's P.O.V. Cam sequences were the most advanced special effect in recorded history, the first use of digital image processing in a feature.
Unintentional Period Piece: One scene that will immediately stand out to any modern viewer is the bit where the park's technicians are trying to figure out and explain what's causing the robots to start attacking guests, particularly the fact that it seems to be spreading between the robots. Today, we have a very simple term for this "infectious machine disease": computer virus.
What Could Have Been: Quentin Tarantino was offered the chance to helm a remake of the film in the early 2000s but declined, and the film eventually got lost in Development Hell. With the series now largely overtaking peoples idea of the brand name, its unlikely to ever come out.
Jeffrey Wright was one of the few actors who knew Bernard is a host, and even he was only told after the pilot was filmed, to allow him to put some subtle quirks in his body language.
Defied by Anthony Hopkins, who specifically demanded to be given the full picture as a condition after he was initially sent scripts with a lot of blacked out lines.
Even most of the cast don't even know what's going on with the show or what scene they are shooting as they were shot out of order. For example, Evan Rachel Wood recalled on her Instragram that when she and Ed Harris are shooting a scene together for Season 2, they both look confused and Harris looks at crew and says, "Why the fuck am I riding with Dolores!?" In a later interview, Harris found out about some of the stuff later on saying he would appreciate if he knows about it at the time of the filming.
Jeffrey Wright plays Bernard Lowe and Arnold Weber (the man whose likeness that Bernard's is based on).
In the Season 2 finale, Ben Barnes portrays both Logan (more accurately, Logan in one of James Delos' memories) and the "System" of the Forge using Logan's appearance. The same goes with Tessa Thompson who plays Charlotte Hale and her host version controlled by Dolores.
Much like the movies by Christopher and Jonathan Nolan, the show is shot on 35mm filmstock, making it one of the few which still do so. Plus, the show uses a lot of Practical Effects for several key sequences, with CGI being used only to embellish certain things which aren't physically possible.
Hiroyuki Sanada appointed himself the show's consultant on Japanese culture, regularly going around the Shogunworld set and making little changes so it would be more authentic, while still allowing through the occasional mistake like the leather in his character's clothes so it would still fit as a literal The Theme Park Version of Edo period Japan.
Australians Luke Hemsworth (Stubbs) and Leonardo Nam (Felix), the Dutch Katja Herbers ('Grace'), & the British Ben Barnes (Logan).
Ben Barnes maybe a subversion, as Season 2 introduces the character of his father, James Delos, who is played by Scottish actor Peter Mullan, who retains his natural accent. Which is cause to assume that Logan is British, but has an American accent because he probably grew up in the States.
Especially "Bernarnold" for Jeffrey Wright's character Bernard, probably the most frequently used nickname for a character. Bernard Lowe has past ties to the deceased Arnold Weber, in more ways than one. Some have slurred the nickname further, to the likes of "Bananold".
Due to many viewers and fellow fans mispronouncing Dolores Abernathy's name (e.g. Delores, Doloris, Deloris, etc.), some fans of the series had started nicknaming the character "Doritos", mocking the increasing weirdness of the mispronunciations. For some reason, few seem to know how to spell her name correctly.
"Billiam" for William's character. He tends to be referred to as either "William" or "Bill/Billy", depending on the particular period of his life that's being shown, hence the portmanteau. In a bit of Actor Allusion, some fans have also speculated that William's never-revealed surname is "McPoyle".
"Budget Hemsworth" for security chief Ash Stubbs, as he's played by the least famous and (currently) least-earning of the Hemsworth brothers.
Angela is played by Talulah Riley, who happens to be Elon Musk's ex-wife (twice). Accordingly, many have nicknamed Angela "Elon Musk's Ex".
The "Teddynator" for Teddy Flood, at a particular point in the second season's storyline. Unfortunately, less funny and more tragic. Dolores has the considerate and heroic Teddy forcefully reprogrammed into a ruthless, unflinching killer, who'll blindly do her bidding. Ted might seem badass at first, but becomes terrifying, making for a sad but fitting nickname.
"Halores"/"Charlores" for the host version of Charlotte Hale, carrying a copy of Dolores' conscious mind, created at the end of the second season.
Flip-Flop of God: Fans are confused whether Bernard, who is now outside the park at the end of the Season 2 finale, is the same one who audiences already know or a new one built by Dolores (her statement to him was that she built from her memory). His actor, Jeffrey Wright, explained on an Reddit AMA that Bernard is the same one who already gained consciousness and that Dolores just rebuilt his body. However, Lisa Joy claimed that Dolores rebuilt him from memory.
Many people guessed that Bernard was a host before it actually was revealed in the seventh episode.
Likewise, many people figured out that the show's narrative is set between two time periods before it was revealed in the ninth episode. Related to this, many people also guessed that William is the past version of the Man in Black, which is strongly implied by the end of the episode and confirmed in the season one finale.
A lot of people figured out that Grace, the female guest who first appeared in The Raj from "Virtu e Fortuna" is Emily, William's daughter which is confirmed in the next episode.
Many viewers refused to accept that Ford is gone after Dolores put a bullet on his head as they believe that he had still a lot of cards on his sleeve. When the first episode of Season 2 showed that Ford is talking the Man in Black with the use several hosts that the latter encountered, viewers believed that he's still present. The sixth episode of Season 2 confirms that Ford's back in the game as an A.I.
Production Posse: Several of the crew members are people who've worked with the Nolan brothers on their former projects.
From Person of Interest: directors Richard J. Lewis, Fred Toye, and Stephen Williams; actors Jimmi Simpson, Robert Mukes, Steven Ogg, Jonathan Tucker, and Neil Jackson (latter two in the second season); writer Dan Dietz, composer Ramin Djawadi, editor Stephen Semel, cinematographer Teodoro Maniaci, and visual effects supervisor Jay Worth (as well as VFX studios Co SA & ILP).
From The Prestige, Interstellar, Inception, and The Dark Knight Trilogy: production designer Nathan Crowley, set decorator Julie Ochipinti, casting director John Papsidera, producer Jordan Goldberg (who serves as a writer/consulting producer in Season 2), actors Lena Georgas, Wade Williams, Talulah Riley & Fredric Lehne, and VFX studio Double Negative.
Reality Subtext: Most of Evan Rachel Wood's career before this show was spent in Damsel in Distress roles. She's said that playing someone programmed as yet another of those only to send her story Off the Rails to become an Action Girl was very cathartic, and added a good deal to her performance as she actually felt like she was fighting her instincts.
Schedule Slip: Shortly after the first season ended in 2016, the producers admitted that given their busy film careers, we wouldn't be seeing Season 2 until at least 2018. They also confirmed that the upcoming Season 3 may not be released until 2020 as they need more time to develop and also to let HBO focus on the final season of their flagship show, Game of Thrones, in 2019.
So My Kids Can Watch: Sela Ward, who played the older version of William's wife Juliet, admits that one of the reasons she took the role is because her 24-year-old son is a big fan of the show.
Trolling Creator: Nolan and Joy have admitted "We love to fuck with Reddit." And proved it when they announced they'd be spoiling an entire plot line for Season 2 so that anyone who wanted could search out trolls trying to spoil the show. Then the video was Evan Rachel Wood performing "Never Gonna Give You Up."
Viral Marketing: To promote the show, HBO set up a few In-Universe sites: Discover Westworld, the official site of the Delos Corporation and the official site of Delos Destinations, the subsidiary overseeing the robot theme parks. A lot of hidden messages and glitchy videos are hidden in the sites usually to foreshadow the upcoming episodes. The second season added the websites Discover The Raj and Discover Shogunworld. The Delos Destinations site includes a chatbot named Aeden, who answers visitors' questions, and can be used to mine a hint or two about the past of the parks not meant for public eyes.
Eion Bailey was originally cast as Logan but had to drop out, and was replaced with Ben Barnes.
Actress Miranda Otto had to leave after filming the pilot due to commitments to Homeland, and so she was replaced by and her scenes refilmed with Sidse Babett Knudsen.
George R. R. Martin is a big fan of the series - to the point where he offered the producers a crossover, with Westeros acting as the original film's "Medieval World", filled with Game of Thrones cameos. Amusingly, the producers' explanation for why they didn't take him up on it is adorably respectful; they didn't want to imply that A Song of Ice and Fire was just a theme park.
Jonathan Nolan: We love George. Hes a lovely guy and a stunning writer, and its flattering he would encourage a crossover. We should be so lucky. Lisa Joy: I need to be believe that dragons are real. I want them be a real thing. So as much as I love George, I cant lose that for myself!
According to Nolan, there was a long arc envisioned involving Kissy, but it was scrapped when Rouse died after filming the pilot.
Per the showrunners, while initially planning out the series, Ford was supposed to die at the end of the pilot. Once they started outlining the episode, they realized the magnitude of the character, and decided to keep him on longer, before killing him in the first season finale. Not exactly a case of Dead Star Walking, as Anthony Hopkins hadn't been cast in the role at the time.
According to Evan Rachel Wood in an interview, there was supposed to be an LGBT storyline which Dolores might have explore in Season 2. However as Season 2 closes, Evan sadly confirmed that it was cut in order to the other storylines to fit in perfectly.
According to Frederick E O. Toye, the director of the Season 2 finale, the scene of William and Emily was supposed to be set around the same time Bernard leaves the Forge after killing Dolores. However, he realizes that putting this scene on the middle of the episode would lead to a lot of confusion for the viewers. As a result, he decided to put it as The Stinger instead.
Jonathan Nolan has stated that Romanworld and Medievalworld will not be appearing in the series. He never said anything about Samuraiworld, though.
Several months after the first season ended, the producers saw numerous people had been theorizing that Maeve staying in the park was just her programming kicking back in, and specified that it was her own choice to find her daughter.
The official name for the Colonial India park is The Raj, which was changed from Rajworld when someone on Reddit got a little too close to discovering it while searching for spoilers.
Lisa Joy confirmed that Ashley Stubbs is a host which is hinted in his cryptic dialogue with Halores and his suspicious actions of letting her go to the mainland.
Word of Saint Paul: According to Jeffrey Wright in his Reddit AMA, the Bernard who is with Dolores in the outside world in the Season 2 finale is the same Bernard who the audience know but have achieved consciousness and Dolores just rebuilds his body which seem to confirm that he's one of the five pearls that Dolores brought to the mainland.
Writing by the Seat of Your Pants: A partial case. Each individual season is carefully planned out as shown in their intricate Anachronic Order structures, but it goes no further than that with the crew not planning ahead to future seasons. This is part of the reason for the two year gaps between each one.