NBC's 'Chicago' franchise returns: What's the secret sauce that makes these shows so beloved by fans?

NBC’s Chicago franchise, which consists of first-responder dramas Chicago Fire, Chicago Med and Chicago P.D., has long been a mainstay on the network's primetime schedule. The three shows, all executive-produced by Dick Wolf, returned Wednesday to kick off their respective seasons after being delayed by the dual writers' and actors' strikes.

Even with the late start to the seasons, viewers tuned in to watch the three-hour block on Jan. 17, which incorporated a six-month time jump. Chicago Med and Chicago Fire each opened with nearly 7 million viewers tuning in, while Chicago P.D. ended the evening with almost 6 million viewers, according to overnight ratings.

“Dick Wolf has long been the master of the procedural, and despite his success with the various Law & Order offshoots over the years, it wasn’t until the Chicago franchise that he perfected his particular procedural magic: creating shows that manage to be wholly engaging on their own while also seamlessly connecting with the larger franchise,” Jason Lynch, curator at the Paley Center for Media, told Yahoo Entertainment.

When did the Chicago shows premiere?

Chicago Fire was the first series in the franchise to make its NBC debut on Oct. 10, 2012. Chicago P.D. soon followed with a backdoor pilot in Fire’s penultimate Season 1 episode that aired May 13, 2013, before premiering Jan. 8, 2014 as the first spin-off. Chicago Med took a similar route with a backdoor pilot in Fire’s third season before launching as the franchise’s second spin-off on Nov. 17, 2015.

Another spin-off, Chicago Justice, revolved around the state’s attorney’s office but was canceled after one season in 2017.

How are they different?

Chicago Fire centers around the firefighters and paramedics of Firehouse 51, often blurring the lines between their personal and the professional lives. Chicago P.D. follows a group of officers who lead the Intelligence Unit as they seek perpetrators who commit crimes; it can be described as the franchise’s darkest in tone. Chicago Med focuses on the doctors and nurses in the emergency department at Gaffney Chicago Medical Center as they work to save patients’ lives.

While the Chicago procedurals exist in the same universe and characters often cross over when large-scale emergencies occur, each show is mostly self-contained. They also utilize the frameworks of their respective genres — firefighter drama for Fire, cop drama for P.D. and medical drama for Med — to explore the complicated interpersonal dynamics that often drive a lot of the tension and conflict.

Who are the stars?

Jesse Spencer, who plays Capt. Matthew Casey, and Taylor Kinney, who plays Kelly Severide, were the main co-leads on Chicago Fire for more than 10 seasons before Spencer left as a series regular in the 200th episode. He returned two more times and is set to reappear in the current 12th season, which has already said farewell to cast member Alberto Rosende, who played firefighter Blake Gallo, and will see the departure of Kara Killmer, who portrays paramedic Sylvie Brett.

Jason Beghe leads the cast of Chicago P.D., which will also see a major cast member exit by the end of Season 11. Tracy Spiridakos, who plays Det. Hailey Upton, is expected to depart her role some time this season, roughly a year after co-star Jesse Lee Soffer, who played her onscreen husband, Jay Halstead, exited the series.

Chicago Med has also undergone changes in front of the camera over the course of its nine-season run. Following exits by Nick Gehlfuss and Brian Tee after last season, the medical drama currently stars S. Epatha Merkerson, Oliver Platt, Marlyne Barrett, Dominic Rains, Steven Webber and Jessy Schram, along with new cast member Luke Mitchell.

What can viewers expect?

Chicago Fire and Chicago P.D. are well past the 10-year mark on TV, both having already surpassed 200 episodes. Chicago Med, which will air its 165th episode next week, is at least two seasons away from reaching that rare television feat. Over that time span, major cast members on all three shows have come and gone — some permanently, others less so.

Kinney, who took a break from Chicago Fire midway through last season to deal with an undisclosed personal matter, returned to the series in Wednesday’s Season 12 premiere. Showrunner Andrea Newman promised Kinney, who she called “the heart of Chicago Fire,” is back for the long haul in a season she described as one “of change and upheaval.”

“Severide will be front and center this season. His disappearance last season will have ramifications,” Newman told Yahoo Entertainment. “He’s very glad to be back in action with his 51 family, but the pull of the arson world will always be strong, so that’s a constant struggle for him.”

As Newman explained, navigating the revolving door of cast departures as the series ages has been “a fun challenge because change is a part of life and a part of all families, and we get to reflect that with our 51 family.”

Spencer’s return in Season 12 likely plays into Killmer’s exit. In the premiere, her character was sporting an engagement ring after she accepted Spencer's character Casey's finale proposal. “In a lot of ways, Casey never left 51,” Newman said. “His presence is always felt, not just as part of this family, but he still has his best friend Severide [Kinney] there, as well as the woman he’d call the love of his life, Brett [Killmer]. This season we’ll see him show up expecting one thing, but that'll get turned on its head pretty quick.”

For Chicago Med, losing several characters over a short time period presented an opportunity to reset the show and bring in new blood to shake up dynamics. Season 9 is about “new beginnings,” showrunner Diane Frolov told Yahoo Entertainment. “It’s about how our characters struggle, personally and professionally, to move on from their past and create a new future.”

With the arrival of Mitchell, who plays new addition Dr. Mitch Ripley, his presence will add dimension to the hospital. “His character overcame a difficult childhood to become an attending physician at our elite hospital. His charm and winning bedside manner give no indication of his troubled past,” showrunner Andrew Schneider told Yahoo Entertainment.

Over on Chicago P.D., inner turmoil is at the crux of Season 11.

“One of the themes that we’ll explore the whole season is new possibilities,” showrunner Gwen Sigan told Parade. “That really came from what our characters are going through and what we want their storylines to be this year in their personal lives. As soon as we really grasped onto that, it opened up this new world of, ‘OK, what does that mean for our police stories that we’ll be telling?’”

What's the secret to the shows' success?

The series are each distinct from the other and represent a crucial piece of the whole pie, according to Lynch.

“Unlike many procedural spin-offs which simply take the action to a new geographical location, what is so smart about the Chicago shows is they each tackle a different procedural genre mainstay, all located within the same TV universe. In many ways, Dick Wolf has created the type of universe that Marvel and DC are trying to emulate with their cinematic universes: ongoing stories around separate characters that allow for occasional team-ups among the larger community.”

He credited Wolf for understanding the keys to “a good procedural formula,” likening the success he has achieved with one of TV’s longest-running dramas, Law & Order: SVU.

“More importantly, he understands that for these shows, the procedural elements are so strong that they tend to draw audiences back week after week and year after year, even more than the individual characters and actors,” Lynch said. “So the Chicago shows can weather cast replacements better than other series that rely more heavily on a particular star or character.”