The producers had a choice between keeping Slade Wilson as an American, like in the comics, and casting Maori actor Manu Bennett in the role. They took the second option and turned Slade into an Australian spy.
Stephen Amell is also a case of this - in the present day he looks mid-to-dark brunette as Oliver (like Stephen is in real life), but in flashbacks where he has longer hair and a beard both are clearly dirty-blond (making him resemble the comic's Oliver Queen a lot more). Because it would be hard to die his short-cropped hair (let alone his stubble), and because Amell portrays the character so convincingly, most people treat this as Acceptable Breaks from Reality and are generally not bothered by it... Worth noting is that Oliver's probably supposed to have a shade of blond in the show as well (that simply looks darker in the present thanks to lighting and shortness), because both his parents are blond and Thea is really Malcolm Merlyn's biological daughter, thus explaining her own brown hair. Further, Amell also has a larger frame compared to the comics' Ollie (who has toned arms but a smaller overall frame than heroes like Batman and Superman - his frame would be more in line with Smallville's Justin Hartley in comparison), but overall few people have expressed displeasure with this.
Caity Lotz taking over for Jacqueline Mcinnes Wood as Sara Lance is also an example. Season 1 firmly established her as a tall, raven-haired woman and both of those traits became an important plot point for her family's arc late in that season. Caity Lotz's entire appearance is far different from Jacqueline Mcinnes Wood's, but her excellent portrayal of the character made the fans ignore and look past the major Continuity Snarl caused by the recasting.
Much like Shado, Celina Jade was taught martial arts by her father.
Neal McDonough is in fact married to a woman named Ruvé.
Katherine Mcnamara is highly intelligent just like her character Mia.
Approval of God: Stephen Amell has "Meme Monday" on his Facebook page, where he reposts memes of the show that he finds funny. He's also infrequently done a "Fanart Friday" with a similar theme. He's also done some bizarre one-offs, such as "Lightsaber Saturday" where he does the same sort of thing only with a specific theme.
Ascended Fanon: Canon Foreigner John Diggle proved to be a fan favorite from the beginning. However, some fans speculated thanks to the overall look and the military background that Diggle might actually be John Stewart, better known as one of Earth's Green Lanterns in the comic books. The showrunners generally loved that idea and despite not being able to use Green Lantern directly throw in hints towards thar theory, like John having a step-father with the last name Stewart or the Earth-90 Flash recognizing John and the lack of a "ring"... The series finale goes straight for it, seeing John finding a package from space with a green light in it, outright confirming John would go on to become the Arrowverse's version of Green Lantern. Unfortunately this was never shown, with some theorizing the Warner Bros rejected letting him suit up.
Stephen Amell really does the salmon ladder in real life, so why not put it in the series too, right? He could also do parkour and pro-wrestling, so why not do them on-screen, too?
Summer Glau's character, Isabel Rochev, was not initially going to be a villain, rather a red herring. However, Summer was dissatisfied about being in a superhero series without getting in on the action, so Isabel Rochev became the Ravager.
Not regarding the show itself, but Stephen Amell has quite happily voiced his displeasure over how the execs handle promoting the show, namely that the posters highlight the ensemble cast, but leave out Paul Blackthorne and Susanna Thompson. He similarly criticized WB for announcing plans for a Flash film and a new actor the day after The Flash posted strong second-week ratings, showing true staying power, feeling it undercut both the show and Grant Gustin.
In an example regarding the show itself, Stephen Amell once made a list of the seasons he considers to be the best to the worst. While this in itself wouldn't be an example (since a season would have to be considered "the worst" no matter what) many fans were quick to notice that the universally despised Season 4 is nowhere to be found on that list.
Caity Lotz was understandably not pleased with her character's treatment in Season 3, being killed off in the premiere and then strung along for two more appearances anyway, as a fake voice, and a hallucination. However, she was pleased to be resurrected in the fourth season of Arrow and move on to Legends of Tomorrow, where she elevated to the ensemble's lead character as team captain.
Marc Guggenheim and co. admitted "[they] fucked up" with how they forgot about Roy at the end of the Arrow vs. Atom fight in "Suicidal Tendencies". They also wished, in hindsight, to have Oliver join the League earlier to allow more time to play around with "Al Sah-him".
Emily Bett Rickards admitted she wasn't happy about the writers playing down her character's comedic side in exchange for angst during Season 3, and said she looked forward to having funny and happy Felicity back in Season 4, which unfortunately for her went From Bad to Worse. Speaking of which, she also did not like how Felicity's disability storyline was quickly brushed-off as Rickards was enthusiastic (or "excited" as she puts it) to represent people coping with disabilities (it's also worth mentioning that Rickards is an advocate for PWD charity groups) and even made a lot of effort to research the subject. For the matter, she's also been very vocal against Felicity having a pregnancy storyline, feeling that it would limit her character and the narrative. The writers pushed through with it anyway, though they also compromised by having a Time Skip so that Felicity would have already given birth.
Comments Bennett has made on social media also seem to indicate he shares the fandom's sentiments regarding the show's Seasonal Rot / Romantic Plot Tumor and no longer desired to be part of the show, a factor that has likely contributed to Slade's Long Bus Trip, which ended when he returned in the second half of season five.
Geoff Johns: Let’s say you’ve been given the position of writing Green Arrow from scratch. Clean slate. You might say, ‘Okay, I’m going to write this new character,’ and when someone says, ‘Well, what about Black Canary,’ you might say… ‘nope.’ That means you completely misunderstand these characters.
Even Marc Guggenheim, the fandom's scapegoat, has owned up to some of the issues people had with Season 4; by his admission the Olicity relationship wasn't handled "as naturally and elegantly" as it should have been, and some of that season's problems can be boiled down to planning narrative points without a graceful execution.
John Barrowman was not happy about Malcolm being killed off. He was only told his character would be killed off the night before the shot the scene and that Malcolm wouldn't be coming back in Season 6; keep in mind Barrowman's contract had been renegotiated for the 2016-2017 so could be on any show if the producers wanted. Barrowman justifiably angry at this development, then told the producers "where they could shove it". Then Guggenheim said in an interview that John was more than happy to come back if he wanted. Barrowman believes they never showed Malcolm's corpse as way for Guggenheim to protect himself from any backlash.
In the same interview, Barrowman spoke for Alex Kingston and reveals that she wasn't happy how her character was turned into "a screaming mamma". The fact that said character is the original Black Canary in the comicbooks and suffered a massive case of Adaptational Wimp also does not help. Ms. Kingston herself later confirmed those.
After the episode where Thea was Put on a Bus, it is revealed that Willa Holland had wanted to leave the show since the conclusion of Season 4, which explains why Thea was Commuting on a Bus for Seasons 5 and 6 before the writers finally let her leave.
Stephen Amell has told people who use the meme of Grant Gustin posing next to Oliver's grave to "kindly fuck off".
Most of the young adult characters are portrayed by actors 2-4 years older and so convincingly pass themselves as those ages; Katie Cassidy (Laurel Lance) and Emily Bett Rickards (Felicity Smoak) are in fact younger than their respective characters. The flashbacks, on the other hand, cannot avoid this pitfall because they also function in chronological order but are always 5 years behind the present-day scenes: 23-year-old Willa Holland stands out when portraying a 15-year-old Thea Queen in Season 3's "The Return".
Jamey Sheridan (b.1951) and Susanna Thompson (b.1958) are both 6-7 years older than their respective characters Robert (b.1958) and Moira (b.1964) Queen.
In Season 2, Isabel Rochev mentions that she's under 30 years old. Summer Glau was 32 at the time.
David Ramsey (John Diggle) directed Season 7 episode "Past Sins" and Season 8 episode "Reset" .
Katie Cassidy (Laurel Lance) directed Season 8 episode "Leap of Faith".
Disowned Adaptation: Terry Beatty, one of Wild Dog's co-creators in the comicbooks, was not happy with his Costume Evolution in Season 6, citing that the costume is the only thing faithful to the otherwise In Name Only character.
Terry Beatty: THIS, ladies and gentlemen is what the powers that be at the Arrow TV show have decided is Wild Dog’s new —> “improved” look. Yup — THIS is Wild Dog. Since the costume and name were all that survived from the comic book to begin with, this is now literally Wild Dog in name only. This change erases any trace of the original Collins/Beatty concept for the character. I would not be surprised if his name gets changed before too long, as well.
Whatever was unique about his “street level” costume has been replaced with the current standard issue dark armored uniform — a generic “third Imperial Guard from the left/Death-Blood-Stroke-Stryke/Image big gun” look. Sigh….
Oh well, I got a year’s worth of seeing how cool my costume design looked on screen — a validation of my work in a lot of ways. I suppose it was too much to expect it would last.
I will tip my hat to Rick Gonzalez, who I feel has done a fine job in the role and has a strong screen presence. I wish him luck in going forward with this and whatever else he does down the line.
Dueling Shows: With Agents of S.H.I.E.L.D., at least in their second and first seasons, respectively, since they were the only ones running in that period. Both series fall under the long-standing DC Comics/Marvel Comics rivalry.
Dye Hard: John Barrowman cheerfully admits to dyeing his hair brown for his role and that he's been completely gray for years.
Dyeing for Your Art: Katie Cassidy lost a significant amount of weight during the production of season two, to better convey Laurel's addictions to painkillers and alcohol. The following season, Katie bulked up in the gym as Laurel suited up as Black Canary.
For a time, certain big-name characters such as Superman and Batman were not able to appear in the show’s universe as WB reserved them exclusively for the emerging movie franchise. However, in season 4, Supergirl crossed over with The Flash in the former's first season. Superman would be introduced in the next season, and does in fact travel to Earth 1 in the Elseworlds crossover of season 7. Oliver would namedrop Bruce Wayne in a season 6 press conference. He was stated in Elseworlds to have been a vigilante at some point but has since left Gotham. Finally, a Batman from Earth-99 played by his recurring voice actor Kevin Conroy would appear in the Batwoman (2019) portion of Crisis on Infinite Earths.
Despite him already appearing, Deadshot was made unavailable for the show for movie franchise reasons, after Will Smith was confirmed to be playing him in Suicide Squad. It was explicitly confirmed that this is why he was killed off in season 3 episode "Suicidal Tendencies". This also affected other characters who appeared in the same film, such as Harley Quinn and Amanda Waller.
Several other characters were made off-limits as well, including Ted Kord (as mentioned below).
After Justice League (2017) came out it was announced that Warner Bros told the producers that they could no longer use Slade Wilson anymore, again meaning that "Promises Kept" will probably he the last time he'll be seen. At least he's still alive.
Executive Meddling: A lot of fans felt disappointed by what they felt was a rather slapdash, poorly plotted seasons 3 and 4 after the highly lauded season 2. What the audience didn't know at the time was that the writers had planned arcs for those seasons based around Slade Wilson and the Suicide Squad. When those characters were Exiled from Continuity as stated above, the writers had to quickly throw some last-minute replacement plots together. The results were less than satisfying for many fans, and the general consensus is that the show didn't really recover until Season 5.
Paul Blackthorne (Quentin Lance), John Barrowman (Malcolm) and Alex Kingston (Dinah) are all British, though all three have extensive US experience. Barrowman in particular was raised in the US, holding dual nationality, and can switch easily between American and Scottish accents, speaking both with native ease.
The late Darren Shahlavi was Iranian-English, but played the American Constantine Drakon.
Fake Australian: Digger Harkness is Australian in the comics, but here played by Lebanese-American Nick Tarabay.
Fake Brit: All member of the "Al Ghul" family speak with an English accent, but none of their actors are English: Nyssa is played by American Katrina Law, Ra's himself is played by Australian Matt Nable, and Talia is played by Canadian Lexa Doig.
Fake Mixed Race: American of Indian heritage Janina Gavankar plays the possibly mixed race (judging from the surname) McKenna Hall.
American of German and Scotch-Irish descent Summer Glau plays Isabel Rochev, a Russian who was later naturalized as an American.
Eugene Lipinski (Alexei) is from England, playing a Russian character.
In fact, almost no Russian characters are played by Russian actors. Anatoly is played by Czech-born Canadian David Nykl, Kovar is played by Swedish Dolph Lundgren, Gregor is played by American David Meunier, Viktor is played by Canadian Mike Dopud, and Taiana Venediktova is played by Canadian Elysia Rotaru.
Guggenheim is infamous for creating tension on set by planning to kill off characters and not bothering to tell their actors about until the last minute; Katie Cassidy and John Barrowman were both unhappy about being killed off a show they didn't want to leave. In Barrowman's case, the situation was handled so poorly that he actually walked away from production completely as soon as he was done - Malcolm's death was intentionally written as Uncertain Doom to keep the door open to a return, but he only returned for the Elseworlds event.
In Katie Cassidy's case there have always been rumors that for one reason or another the production team took a dislike to her and they intentionally gave Laurel storylines to make her unpopular with the audience. When the audience began to grown fond of Laurel in Season 3, the producers responded by killing her off in Season 4. The same can be said for Laurel's popular Alternate Self, whose much anticipated Heel–Face Turn was delayed for two seasons.
In his biography, Colton Haynes revealed that he left the show because he couldn't stand one of the cast member without revealing their name.
Irony as She Is Cast: It's worth noting that Paul Blackthorne's best-known role is magician Harry Dresden, and he plays a cop. John Barrowman's most famous role is him playing a sort of secret agent-slash-cop, and he plays a man whose codename is "Magician".
Marc Guggenheim is notorious for this, especially in season 4 regarding Laurel's character. He told fans that Laurel was going to get her own storyline and villain, but none of that happened during the season and Laurel was killed off before it could happen. Needless to say, fans and even some of the cast were none to pleased of Guggenheim's fib. He also said that Roy would return as a Recurring Character in Season 5. That did not happen and Roy never appeared outside of a Stock Footage hologram.
At HVFF Portland, Stephen Amell claimed that Olicity was always the endgame ship for the show. That was a blatant lie that several people called him out on, as Emily Bett Rickards wasn't even intended to be a series regular at first and only got onto the cast because of her popularity with the fans, cast, and crew. Hell, the only reason she was even a reoccurring character in Season One was because of that. To say nothing about how Season One was clearly structured to support the Lauriver ship, which was canon in the comic book the show is based on. Most speculate this was an attempt to quell the anti-Olicity wave of publicity the show got after the end of 2017 crossover Crisis on Earth-X.
Related to both cases, at one point Guggenheim, shortly after killing off Laurel, tried to downplay how often they engage in Pandering to the Base, specifically for the Olicity fanbase, by claiming they don't take what fans are calling for into account. This, of course, is pretty easy to see isn't the case given how much the show was visibly doing that in the first season, from downplaying Laurel/Oliver and promoting Felicity's character, not to mention its what lead to Sara's revival and Legends of Tomorrow being conceived.
Missing Episode: The run on TNT skips two episodes for Season 4: Constantine's guest episode and the second half of the Arrow-Flash crossover.
Money, Dear Boy: Stephen Amell says that he initially wanted the show to end at Season 7 but was offered a deal for Season 8 that was too good to refuse.
No Stunt Double: Zig-Zagged - Stephen Amell does as much of his own stunts as he's allowed, including the infamous salmon ladder which Amell can pull off in real life, with some of the more complicated/dangerous stuff being done by a stunt double. Same goes for Caity Lotz.
The Other Marty: Devon Aoki was set to play Tatsu Yamashiro in Season 3. However, she dropped out during filming and her scenes were re-shot with Rila Fukushima in the role.
John Barrowman was best known for his roles in musical theatre and for playing AntiHeroes, and Lovable Rogues, which were as far from the nasty Malcolm Merlyn as one can get.
The cold-hearted Isabel Rochev is well outside of Summer Glau's usual repertoire, even moreso now that it's known she's a flat-out villain.
Felicity Smoak's hair is dyed pink as a disguise from Ricardo Diaz in the Season 7 premiere. In Real Life, it's because Emily Bett Rickards had to dye it for a photo shoot.
Earth-2 Laurel is sporting a pulled back bob in the final season. In actuality, Katie Cassidy already had her hair cut in that style by the time of Season 7 but wore extensions. She was finally allowed to keep her natural hairstyle for Season 8.
Reality Subtext: Much like Earth-1 Laurel, Katie Cassidy has a father with drinking problems. And much like Earth-2 Laurel, her father passed away.
Similarly, it's also played with (twice) in the Brazilian dub, related to Black Canary's Decomposite Character status: Fernanda Baronne voiced Dinah in Birds of Prey and voiced Laurel here in the first two seasons; Guilene Conte, who voiced another Dinah Lance version (from Justice League Unlimited), voices Sara Lance here and in Legends of Tomorrow.
The agreement to bring Constantine on the show in Season 4 stated his appearance was a one time deal. This is lampshaded later when Thea asks why Ollie doesn't ask Constantine for help, only for him to reply that he's in Hell. Literally.
Slade Wilson suddenly got made off-limits again by WB halfway through Season 6, meaning that Slade's new storyline remains unfinished to the completion of the show
Separated-at-Birth Casting: Katherine Mcnamara bears strong resemblance in to the actors playing her parents with similar looks to Emily Bett Rickards and similar mannerisms to Stephen Amell.
Sadly averted as the above mentioned Sean Maher and Summer Glauplayed brother and sister in Firefly but never even meet here.
John Barrowman and Alex Kingston both have recurring roles on Doctor Who, though their characters on that show (Jack Harkness and River Song) never met. The announcement of Kingston's appearance here led to excitement that Jack and River might finally meet, but alas, the two actors still haven't appeared on-screen together.
Throw It In!: Every time that Ra's refers to Oliver as "boy", it's because Matt Nable went off-script. The producers left it in because they felt it worked with the character.
Katrina Law regularly pokes fun at all the shippers on the internet.
Colin Donnell loves to comment on fan theories regarding Tommy's character, especially since the popularity of his portrayal led to the character being remade in the comics. The more ridiculous the theory, the more he approves.
Voice-Only Cameo: Tara Strong (the current voice actress for Harley Quinn) has a voice cameo as a "Deranged Squad Female". She can be heard shouting from behind a door, but doesn't physically appear in person.
Justin Hartley, Smallville's Green Arrow, was considered to reprise his role back when the show was still being pitched. The higher-ups then decided that his rendition won't fit the Darker and Edgier tone of the series and amicably parted ways.
Former Black Canaries Alaina Huffman and Rachel Skarsten were also considered to reprise their roles as Laurel Lance for the series. Skarsten was eventually cast as Red Alice in Batwoman.
Before Matt Nable was cast, Liam Neeson said he'd play the show's version of Ra's al Ghul "in a heartbeat". Word of God states that after learning this, the network approached Neeson on the off chance he had the time, but they were unable to reconcile their schedules.
Deathstroke's mask was meant to be just a Easter Egg, but fans were so hyped DC let them use the character.
The character who was going to buy out Queen Consolidated was originally going to be Ted Kord, a character whose existence was already implied through the appearance of Kord Industries. However, DC enacted an embargo on him due to "other plans", so the creators instead went with Ray Palmer. This means that the A.T.O.M. suit functions more like the Blue Beetle or Iron Man suits than it does its comic counterpart. This received an amusing Development Gag the following season, when the team needs to steal a piece of tech from Kord’s company to bring Ray back to normal size.
Mr. Blank was originally supposed to be the DC Comics villain Onomatopoeia. However, as Onomatopoeia only speaks in, well, onomatopoeia, they couldn't make it work without him coming across as mentally disabled (since sound effects sound far different in real life compared to comic books).
Roy was going to return for a guest appearance in season five, but other commitments prevented Colton Haynes from appearing, so his sole appearance in that season ended up being Stock Footage of him for the Crisis Crossover "Invasion!". He eventually returned as a series regular for Season 7.
Malcolm was originally considered to be Oliver's actual father. The showrunners ultimately decided against it since it's too "Darth Vader and Luke" so they gave the Story Arc to Thea instead. Still, this was given a Development Gag in the Season 3 finale when Malcolm tells Oliver that he always viewed him "as a son".
The twentieth episode of Season Two was originally going to be a Back Door Pilot for a potential spin-off focusing on The Flash. Based on both the strength of Grant Gustin's portrayal of Barry Allen in "The Scientist" and "Three Ghosts" and the fact that using the twentieth episode as a Back Door Pilot would interrupt the show's momentum as it built up to the season finale, the decision was made to make it a standalone pilot. In any case, the nineteenth episode of that season ended up introducing two regulars for the Flash series.
In early drafts of Season Two, Sara was originally going to take the role of Ravager, but eventually ended up as the Canary. Instead, the role of Ravager was given to Isabel Rochev.
Season 3 Episode 5 is supposed to be titled "Oracle", but the character was also Exiled from Continuity, hence why it's titled "The Secret Origins of Felicity Smoak" instead.
A.R.G.U.S. and the Suicide Squad were originally planned to be a major part of Season 3 but was scrapped by Executive Meddling.
Vigilante's identity was suppose to be revealed in Season 5, but due to time constraints and the production team unable to get the actor they wanted at the time, the Vigilante subplot was pushed to Season 6.
The second half of Season 6 had to be heavily rewritten after they couldn't get Michael Emerson to commit to a full season, turning his intended Big Bad into a patsy for one of his supposed henchmen.
Slade was going return later in Season 6, but Manu Bennett was unavailable.
Earth-2 being wiped out of existence by a wave of anti-matter in the Season 8 premiere was noted by showrunner Beth Schwartz in interviews after the episode aired that they had to ask for permission from the writing team of The Flash (2014) to do so - which raises the question of what the back-up plan was if they had refused.
Kevin Smith said that he inquired about directing Arrow after directing several episodes of The Flash (2014) and Supergirl, but Guggenheim declined, saying Kevin "didn't fit" the sensibilities of Arrow. What made this baffling was that not only was Kevin a former writer for the Green Arrow comics, but core character Thea was based on the comics' Mia Dearden, aka Speedy, who was created by Kevin Smith.
Writing by the Seat of Your Pants: The flashforward to the grave at the start of Season 4 was made with no idea who was in it. This went about as well as you'd expect.
, especially with his Season 3 appearance wherein he suffers Badass Decay being beaten by Oliver and Thea alone.