The TV series
- Ability over Appearance: Claudette was originally a male character whose gender was flipped after the casting crew were impressed by CCH Pounder's performance.
- Actor-Inspired Element: Vic's sunglasses were purchased on the first day of filming the pilot by Michael Chiklis.
I had no glasses on in that scene, and it was so bright that I needed glasses and no one had anything. So I walked into the bodega that we were shooting next to downtown and bought a five-dollar pair of Polo sport glasses, and those were his glasses.
- Actor-Shared Background: According to Michael Chiklis, all the show's major adult characters are from where their actors are from. Oftentimes, that's where the similarities begin and end.
- Ascended Fanon: Fanon was made canon with the issue of what nickname the writers used for Curtis Lemansky; season one had characters refer to him as "Lemonhead", which was shortened by fans of the show to just "Lem". By the start of season two, characters started referring to the character exclusively by "Lem".
- Career Resurrection: For Michael Chiklis, whose career had fallen into a bit of a lull in the years after his first show The Commish had ended. Luckily, his wife convinced him that he should reinvent his image by working out and shaving his head to open up more opportunities which led directly to him being cast as Vic Mackey.
- Cast the Runner-Up:
- Neither Ronnie or Lem existed in the original script; David Rees Snell and Kenny Johnson initially auditioned for the roles of Shane Vendrell and Terry Crowley, respectively, before Ryan created the roles of Ronnie and Lem for them.
- Frank Grillo was considered for the role of Vic Mackey; while Michael Chiklis was eventually cast, Grillo was instead cast as Officer Paul Jackson.
- Creator Backlash: A mild example, but when asked in an interview whether he felt the show's portrayal of the police had aged well, producer Glen Mazzara replied with "yes and no." He felt the series' frank depiction of police brutality and lack of accountability has held up and successfully conveyed the writers' intentions to not portray cops as heroes, but also admitted that the show's perspective was skewed by the staff being predominately middle-aged white men. He added that were they to make the show today, "it would have to include voices from communities being affected by the police."
- Descended Creator: Executive producer/staff writer Kurt Sutter played Margos Dezerian, a hitman for the Armenian mob.
- Development Gag: The episode "Petty Cash" features a throwaway line about Claudette "borrowing backup from Rampart," reflecting the show's basis on the real-life Rampart Division and its original working title.
- Directed by Cast Member: Michael Chiklis directed four episodes of show, those being Slipknot, Rap Payback, Haunts, and Game Face.
- Dueling Works: With HBO's The Wire, another inner-city Police Procedural about the members of a special police unit.
- Executive Meddling: Episodes three and four were supposed to air in reverse order, but were ordered switched in order to continue the themed arc with Shane's coping with the aftermath of the murder of Terry Crowley. Also, the hiring of Glenn Close in season four was done after FX Network effectively gave notice to Shawn Ryan that they were seriously considering canceling the series after season four. Also, the haphazard splitting of season five and six (as it was filmed, the series was to have ended with Vic being notified that Claudette had found a replacement for him/Vic killing the man he thought responsible for Lem's death was done mainly due to FX constantly going back and forth on how many episodes season five and six would consist of and whether or not the show would have received a seventh season.
- Fake American: American Kevin Hiatt is played by Australian actor Alex O'Loughlin.
- Fake Nationality: Armenian Mob member Margos Dezerian was played by Kurt Sutter, who is American.
- Playing Against Type:
- Michael Chiklis, who at the time was better known for staring in comedic roles like The Commish when he was first cast as Vic Mackey.
- Notwithstanding the likable persona he presents to the public, Antwon Mitchell is nothing like the comical, lighthearted roles previously played by Anthony Anderson in films like Kangaroo Jack and Agent Cody Banks 2.
- Reality Subtext: On numerous DVD commentaries, Shawn Ryan has stated that the character of Detective Dutch Wagenbach is largely based off of the real life/personality of Jay Karnes, the actor who plays the character. This has led to much teasing between Ryan and Karnes (who are long-time friends) on the DVD commentaries, whenever Ryan points out that just about every failed relationship the character Dutch has over the run the series is based (loosely) off of a real life failed relationship Karnes had. This adds a layer of heartwarming to Steve's lawyer Ellen Carmichael, who Dutch is implied to have a real chance with in the finale, reason explained in the trope below...
- Real-Life Relative:
- Vic Mackey's daughter Cassidy is played by Michael Chiklis's real life daughter Autumn Chiklis.
- Vic's wife Corrine is played by Cathy Cahlin Ryan, wife of Shawn Ryan, the show's creator.
- Lawyer Ellen Carmichael from the last episode is played by Jay Karnes's real-life wife Julia Campbell.
- Serendipity Writes the Plot: The 5th season episode Kavanaugh came about partially because Forest Whitaker left his wedding ring on during some early episodes. When the crew realized this, they didn't like the idea of fixing that in post. Instead, they thought of why a guy like Kavanaugh would keep a wedding ring, and came up with the sub-plot involving his ex-wife.
- Star-Making Role: This show would help Walton Goggins land major roles in other acclaimed shows such as Justified, Sons of Anarchy, and even appear in the MCU.
- Stunt Casting: Glenn Close and Anthony Anderson in season four, Forest Whitaker in season five, and Franka Potente in season six.
- Tom Hanks Syndrome: Playing Vic Mackey led to Michael Chiklis being cast as tougher and edgier characters in subsequent projects.
- Uncredited Role: The lawyer that Shane retains in the final season as a go-between never appears onscreen; the voice we hear over the phone is that of Lewis Black.
- What Could Have Been:
- Vic Mackey was originally conceived as a veteran police officer in his late 50s, with Shawn Ryan namechecking Harrison Ford as far as his original vision of what Vic would be like (in other words, Harrison Ford playing a villain). Eric Stoltz was also considered.
- Shane was supposed to have been killed by Vic during their confrontation midway through Season Four (after Shane was ordered to kill Vic by Antwon Mitchell). Lem's death in Season Five wasn't decided until midway through filming of that season; also dropped (but later resurrected as a foiler to keep Lem's death from being leaked out) was the notion of Shane being the one who delivered Danny's baby — and that Danny would die due to complications from the delivery.
- The character of Shane may not have survived Season One if FX had gotten their way. The network didn't care for Walton Goggins and made it clear to Shawn Ryan that they might order Goggins fired at the end of the season. Ryan and the rest of the writers ended up crafting several episodes just to convince the suits to keep Goggins around, and it worked; they successfully saved his job and convinced the network that they were wrong to casually dismiss the actor's talents (which may be why Goggins was later cast as one of the lead actors in the FX series Justified).
- Season Seven might have been quite different were it not for some behind-the-scenes scheduling conflicts:
- The season was originally conceived around Franka Potente reprising her role as an Armenian crime boss; when she decided to do the film Che instead, the writers were forced to rewrite the plotlines involving the Armenian crime syndicate.
- The second half of the season was impacted due to Walt Goggins appearing in the film Miracle at St. Anna; to allow Goggins to do both projects, Shane was turned into a wanted fugitive (which meant that they could film Goggins' scenes within a relative short time).
- Armadillo was originally supposed to appear in every episode of season 2, but Danny Pino had signed onto another role, forcing him to be written out early.
- Trish was originally going to join the strike team in season 4, but Nicki Micheaux was busy with another show at the time so she was unable to return.
- Glenn Close was offered to return to reprise her role as Monica Rawlings in season 5, but Close turned down the opportunity as she had just gotten married and wanted to spend more time with her family.
- David Arquette was seen for the role of Shane.
- Claudette’s firing of Dutch in Possible Kill Screen was originally scripted as “Now go on back to The Barn, pick up your shit and get the fuck out”, in a final attempt by the writers to get that particular word on the air in an organic fashion, made all the more impactful by who was saying it.
- Three songs were considered for the montage that ends season one: Coldplay's "Trouble" (which was eventually selected), R.E.M.'s "Find the River", and an unspecified track by Dave Matthews Band.
- Dutch was originally revealed to have been a serial killer by the end of the series, however, Jay Karnes and Michael Chiklis both objected to the plotline.
- Working Title: Shawn Ryan's original title of the show was The Barn. The FX network feared that potential audiences might be turned away by that, because they might think it was a gardening show or something similar. Rampart was also considered, after the controversial corruption charges against the Rampart division of the Los Angeles Police Department. This title was used in early promotional materials, including several TV spots. Upon opposition from the LAPD, as well as the fact that people not familiar with the Rampart scandal might not understand the name, the title was changed at the last minute to "The Shield."
- Written-In Infirmity: Sofer's pregnancy was written in when Catherine Dent actually became pregnant.
The wrestling stable
- Breakup Breakout: Surprisingly averted. Near the end of their tenure, it was pretty clear that Reigns was chosen as WWE's next top babyface, and began giving him a bigger emphasis. However even after their dissolution and Reigns' thrust into the spotlight, Ambrose and Rollins have both had notable success. Rollins' betrayal of the team led to him becoming the top heel of the company for a while, and he even pinned Reigns to win his first WWE Championship. Ambrose is the "least" successful of the three, but he's the Ensemble Dark Horse and easily one of the company's most popular stars since Daniel Bryan and every match he participates in is always a fan favorite. When Bryan did retire, he arguably became the most popular face on the roster. Eventually, it reached a point where all three men were world champion within three minutes of each other. Reigns lost the title to Rollins (again), only for Ambrose to cash in and win the title off him, finally cementing the Shield's status as the most successful stable in recent WWE history since Evolution. For further aversion, Ambrose was even the first member of the Shield to become a Grand Slam Champion; conversely, Rollins would be the last member to achieve that, as Reigns would complete it a few months after Ambrose did. By the time of the early New 20s, all three were multiple-time world champions across the two top wrestling companies in the world (WWE and AEW) and megastars, cementing them as by far and away the most successful stable of the modern era since Evolution.
- Costume Backlash: None of them were fond of the turtleneck sweaters they wore during their debut or the riot shields they were supposed to have brought down to the ring.
- What Could Have Been:
- Ambrose was suppose to debut earlier through a feud with Mick Foley. Due to Mick not being in any shape to have an extended match anymore, much less a program it was dropped, and he debuted with The Shield. As such, he is the only member of the trio to have not made an appearance on the rebooted NXT until his affiliation with Rollins and Reigns became apparent.
- In their debut, The Shield was supposed to come out with actual riot shields, but they couldn't comfortably navigate through the bleachers with them, so Vince McMahon nixed it.
- Prior to signing with the WWE, Tyler Black (Seth Rollins) had been offered a deal by TNA. Jon Moxley (Dean Ambrose) also had a tryout for them as well. It really makes you wonder what would have happened to them and to Roman Reigns had either signed with TNA instead — the Shield itself might've never existed.
- Plans for their 2017 reunion were repeatedly forced to change, and for nearly a year and a half, it was just one outside factor after another derailing whatever plans WWE had in place for the Hounds of Justice.
- First, their first match back together was supposed to be The Shield vs. Kane, The Miz, Braun Strowman, and The Bar (Sheamus and Cesaro) in a TLC match at the TLC pay-per-view; however, Reigns was removed from the match and replaced with Kurt Angle two days before the event due to a viral infection.
- Then the reunion as a whole was Cut Short due to Ambrose suffering a triceps injury in December 2017. When he returned from the injury the following summer, the trio picked up where they left off, reuniting the night after SummerSlam 2018.
- Two months later, Reigns' leukaemia diagnosis forced plans to change again. Whilst Ambrose's Face–Heel Turn was (according to Rollins) supposed to take place that night before news of Reigns' illness broke, Ambrose and Rollins were given the option to push the turn back or abandoning the angle entirely; both men ultimately decided to go through with it. Whilst never specifically stated, this also carries the implication that plans for the split were rewritten to exclude Reigns.
- By the time Reigns returned to the WWE the following February after entering remission, Ambrose's impending WWE exit at the end of his contract had been announced. Ambrose swiftly underwent a Heel–Face Turn after Reigns returned, and the Shield reunited for one last run before Ambrose left WWE in April.
- Word of St. Paul:
- According to CM Punk, the early concept for the stable was a security team built around Punk to protect his heel run as WWE Champion, with the initial members proposed being Daniel Bryan, The Big Show, and one call-up from FCW/NXT (most likely Seth Rollins). Punk instead suggested that it would be fresher if all three men came up from developmental, specifically naming Seth Rollins, Dean Ambrose and Chris Hero (then working as Kassius Ohno) as his guys. WWE liked the idea, but didn't like Hero, so instead of him they got Roman Reigns, and the Shield would eventually be distanced from Punk in the final product of the storyline. Roman Reigns himself, however, disputes CM Punk's claim here, and it's been noted that the three were among many who'd bonded as part of that FCW-to-NXT-transition locker room.
- According to Rollins, the plan was always for Ambrose to turn on the Shield when he did; upon learning of Roman’s leukaemia returning, Triple H pulled Ambrose and Rollins aside and gave them the option of going through with the break-up, pushing it back a week or just nixing the angle entirely.
