This week, “Big Brother” will make history by being the first primetime show to hit 1,000 episodes. And in true “Big Brother” fashion, the show is celebrating that milestone with a twisty, one-of-a-kind 90-minute episode that will air Thursday, Aug. 27.

“It’s been really interesting and fun to think about how to celebrate the show,” executive producer Allison Grodner tells Variety. “We want to take some time at the beginning to really reflect on the past and, through fan engagement, have some fun reveals of polls that were taken of favorite moments, favorite winners and people that should have won.”

Of course, the historic milestone comes as “Big Brother 28” is currently on the air. The popular reality program that airs three times a week on CBS is a one-of-a-kind social experiment where 16 strangers are locked in a house together for the summer. Each week, the houseguests compete for power and vote each other off. The catch is that not only are the houseguests completely cut off from the outside world, but everything they say and do is broadcast on the 24/7 live feeds.

Julie Chen Moonves has been hosting the show since Season 1, which was a very different game back in 2000. Famously, the first season (which was run by the creators of the original Netherlands version) struggled with ratings. As rumors spread that the show would get canceled mid-season, so did criticism of Chen Moonves as a host.

“I had such criticism from CBS News insiders, they were mad,” Chen Moonves says. “Andy Rooney was very upset that I was a CBS Morning News anchor and then, for 10 weeks, getting on a plane to Los Angeles to host an entertainment show. He went to the press saying that CBS News should immediately fire me. In his opinion, I was single-handedly blurring the lines between news and entertainment.”

It wasn’t until Season 2 that the show took a page from the “Survivor” playbook by introducing more strategic elements, like the Head of Household competition, which determines who holds the power each week. The houseguests also started voting each other off that season.

Those changes resulted in a more cutthroat “Big Brother,” causing a spike in the show’s popularity.

“I tip my hat to them, because they were asked to take over a show in a genre that was very new then,” Chen Moonves says of executive producers Grodner and her Oscar-winning partner Arnold Shapiro, who worked on the show until Season 7. “They are the reason why it is still successful today, because they put in those basic rules to playing.”

Rich Meehan joined as an executive producer in Season 5, and has been working closely with Grodner ever since.

“It would be really hard if the people who haven’t lived this experience for all these years weren’t here to do the show; you’d start going down some of the same paths, which we already know are dead ends,” Grodner says.

She continues: “Since we took off in Season 2, we’ve done well in the ratings, but it didn’t always guarantee that we were coming back the next year. Every single year in those first, maybe 10 to 15 seasons, at the end of the summer we’d go, ‘Are we coming back?’”

Inside the CBS reality umbrella, it was about finding how to differentiate the show from “Survivor” and “The Amazing Race,” which all launched in the early 2000s as part of the craze that erupted from MTV’s “The Real World.”

“We play in the comedy space, we play in the romance space. Obviously, the strategy and game are at the forefront, but there’s these other worlds we’re able to play in,” Meehan says. “If this is a show about people and it’s a microcosm of life, well, people are funny!”

Since Season 2, the show’s overall format has stayed largely consistent over the years — the basic idea being that the houseguests have to outsmart their fellow contestants, vote them out and then convince everyone at the end why they should win $500,000 (upped to $750,000 starting in Season 23). The Power of Veto, introduced in Season 3, crucially gives nominees the chance to save themselves from the block before eviction night.

But it wasn’t until Season 26 when the latest format change, the BB Blockbuster (then coined the A.I. Arena) added another dimension to the gameplay. Now, instead of two houseguests being nominated and only having one shot at safety, three houseguests are nominated every week; on live eviction night after the Veto is played, they go head-to-head to secure their safety.

“The current idea is that it’s like a new format piece for the live show, so I think, at least in the near future, it’s for sure something we’re going to continue to stick with, unless for some reason it stops working or generating,” Meehan says.

The idea for the BB Blockbuster came from watching “Big Brother 20” contestant Kaitlyn Herman fail to complete a puzzle after she was given a chance to save herself as part of a big twist.

“It captured so much energy and it was fun to watch. We were like, ‘How can we do that in the live show?’” Meehan says. “It’s super simple, but hey, increase the nominees and you’re making more enemies in the house, which creates more drama. And then also, we have this great ‘can’t miss’ sporting event that you have to watch. You don’t know who the final two up for eviction are until that moment.”

After all, Big Brother’s motto is “expected the unexpected.”

“We add in the twists and turns because more and more, you need those things that are promotable and you need those ‘can’t miss’ moments,” Grodner says. “We have what is the ultimate endurance competition in ‘Big Brother,’ just the whole season. Unlike other shows, we need to sustain interest for, in this case, 50 episodes.”

Some fans prefer when the game has fewer twists that disrupt the natural flow of alliances and power structures. “But you also remember we’ve got so many seasons that the new cast can watch; we need to make sure that there’s still something to keep them on their toes, right?” Grodner says. “That there’s still going to be something unexpected.”

On other reality shows, long-standing hosts have become more creatively involved behind the scenes over the years. Take Jeff Probst, the show’s host who also took over as showrunner 15 years ago.

Chen Moonves says that’s not her lane.

“I might suggest things, like ideas when we’ve had ‘Celebrity Big Brother,'” Chen Moonves says. “I like just being the host and not having that pressure of having to do creative or the casting.”

Of all the reality TV fandoms, the “Big Brother” online community is one of the most active, largely incentivized through the show’s 24/7 live feeds. Like all fandoms, that comes with both enthusiasm and sometimes criticism of production.

“We love the fans and their engagement, whether it’s passionate and opinionated, but we would be remiss if we produced a show based on just what’s happening on Twitter,” Grodner says. “And honestly, the creative for the show — how the summer is going to lay out and all that, for fairness reasons and so forth — is actually done well before the season starts. So those kinds of, ‘Oh, we’re adjusting something because of what’s being said online’ absolutely does not happen.”

As a social experiment, “Big Brother” is also a microcosm of society. Because of the live feeds, everything the houseguests say gets recorded. Racist and homophobic comments over the years have made headlines — in the most extreme instance with Season 15, leading several houseguests to lose their jobs.

The show has become more diverse since the 2020 CBS mandate, which set a standard for the network’s unscripted shows to feature at least 50% people of color in the cast. Historically, Black people have struggled against the odds on “Big Brother.”

“I remember when that mandate came down. I felt like, ‘Boy, at that point in history, we really needed it,'” Chen Moonves recalls.

“It’s great, because anybody can win [now] — I don’t think there’s anything holding anybody back,” Meehan adds. Since Xavier Prather’s groundbreaking Season 23 victory, the show’s winners have all been people of color.

Many show segments over the years have featured contestants talking openly about race, identity and how that shapes the way they navigate the game. Since the show casts complete strangers from different walks of life, watching them play against each other also leads them to learn from each other’s differences.

“[Those conversations] happen more than ever, but there have been many in the history of the show. I remember Ken and Bunky [from Season 2]?” Meehan says. “What’s happening in the world is going to happen in the house. It’s just the nature of the show and that’s why people play the game differently now than they did 25 years ago.”

As “Big Brother” nears another milestone with its upcoming 30th season, that also raises another question that many fans have been asking — will we ever see an all-winners season similar to what “Survivor” did with Season 40?

Yet because “Big Brother” is a three-month commitment, that’s a lot tougher of a sell for even the most cherished vets. Chen Moonves has pitched multiple versions of an all-winners season over the years, although she’s made some tweaks.

Her current take is multiple month-long versions of the game, akin to “Celebrity Big Brother.” One shortened season would bring back all the Season 1 houseguests to see how they’d play in the modern era of the show, while the next shortened season would group winners from different eras of the show.

“I think if it’s shortened, everyone would be game. I haven’t heard of a past winner who’s bitter, who never wants to have anything to do with ‘Big Brother,'” Chen Moonves says.

When looking to the future of “Big Brother,” some fans have speculated if Season 24 winner and “Big Brother: Unlocked” host Taylor Hale is being positioned to take on hosting duties were Chen Moonves to retire.

“I’ve wondered that too because, to me, she would be perfect,” Chen Moonves says, praising her on-air skills from serving as an “Entertainment Tonight” correspondent.

Chen Moonves also pitches Season 16 winner Derrick Levasseur, as well as Jeff Schroeder and Jordan Lloyd from Season 11 and 13, as possible options.

“But then I don’t know how the network would feel about, ‘Is it too close to home that they’ve walked in their shoes? Does that put them too much in a position of judgment?'” she says. “Part of me feels like maybe you want to keep the air pristine and have someone who comes from a news background. I got hired because I know how to do live interviews.”

“But old-school journalists,” Moonves clarifies, referencing Anderson Cooper and Andy Cohen as potential options. “I feel a lot of journalists today go on the airwaves and I know exactly how they feel about an issue that they’re covering. To me, that’s not cool. Because then you have an agenda, you’re not really reporting.”

The reality TV landscape has changed a lot since “Big Brother” premiered back in 2000. In recent years, “The Traitors” has dominated the online conversation around competition shows — and even cast “Big Brother” veterans like Danielle Reyes and Britney Haynes.

“I do still think we are very unique, which is amazing to say that 28 seasons in, we still set ourselves apart,” Grodner says, adding that “Love Island” does have its own real-time element with how the episodes are structured. “But we dare to stream live and to have that other part of the show that people can interact with; no other show has done the live feeds to date.”

Leaning into comedy and absurdity, Grodner says declaratively, is what makes “Big Brother” set itself apart tonally, and will ensure, she hopes, the show’s future far beyond Season 28 and the 1,000th episode.

“Can any other show pull off a person in an egg suit, crying or screaming at someone at the nomination ceremony? And a teapot being banged around and have that become part of pop culture instantly?” Grodner says. “We can pull that off, but we can also pull off these amazing, compelling conversations.

“I think our range is unique, and I don’t know if any other show can encompass all of that,” she says. “I guess I dare them to!”