A cross between “Survivor” and the party game Mafia, the competitive reality show arrives on Peacock after a British version became a word-of-mouth hit.For television fans, a favorite reality show can spawn viewing parties, themed WhatsApp groups and memorable moments quoted without context.But James Symonds, 25, a British graphic designer, recently became so obsessed with the BBC reality game show “The Traitors,” that he hosted a party at which he and his friends re-enacted its first season.“Never has a TV show ever had me like this,” Symonds said in a video interview. After watching episodes broadcast live with his partner, he said they “had so much sort of adrenaline we couldn’t sleep.”“The Traitors,” which premiered in Britain in November and has an American version arriving Thursday on Peacock, NBCUniversal’s streaming service, is an adaptation of the Dutch television game show “De Verraders.” The British version was unusual in that it was not the typical type of show broadcast on the BBC, but it was one of the most talked-about shows of 2022 in Britain.A blend of “Survivor” and the party game Mafia, “The Traitors” is set in and around a castle in Scotland. Contestants work together through a series of grueling challenges to win money that is added to a final prize fund. Participants are divided into “Traitors,” whose identities remain secret and who choose a player each day to “murder,” and “Faithfuls,” who try to uncover the Traitors’ identities throughout the show.The whole group also votes for those who it thinks are Traitors, eliminating the person or people from the show. The result is a thoroughly unpredictable competition series.The British and American versions of the show were filmed at the same Scottish castle.Mark Mainz/BBCIn a scene from the British show, the contestants gathered to discuss who they thought were the Traitors.Mark Mainz/BBCFor Symonds’s party, he secretly assigned Traitors and Faithfuls, repeated monologues from the show’s host, Claudia Winkleman, and warned guests, “‘You can no longer take each other at face value,’” he said.Like in the show itself, the party became immersive. “My friend had brought his relatively new girlfriend along,” Symonds said. Soon, her boyfriend had been “murdered,” and “everyone just turns on her,” the host said, accusing her of targeting her boyfriend.This tendency for viewers to take the show’s gameplay almost as seriously as the contestants helped “The Traitors” become a word-of-mouth hit in Britain.“It’s a format that creates an enormous amount of drama,” said Stephen Lambert, whose production company, Studio Lambert, made the American and British versions of “The Traitors,” “and it is ultimately about the way in which people make judgments about each other.” In Britain, the show was broadcast during prime time, three times a week on the BBC, but it found a bigger audience during its run on the BBC’s streaming service, iPlayer (an average of 3.7 million viewers watched the first episode within the first seven days of its broadcast, with more than 1.5 million viewers watching the episode in the subsequent weeks, according to figures from the BBC).All 10 episodes of the American version of the show, which were filmed at the same Scottish location before the British show was shot, will arrive on Thursday on Peacock.Contestants on the American version of “The Traitors,” from left, Shelbe Rodriguez, Rachel Reilly, Stephenie LaGrossa Kendrick and Ryan Lochte.Euan Cherry/PeacockThe U.S. show’s format is similar, but with a couple of adjustments: The Scottish actor Alan Cumming hosts, and half of the show’s 20 contestants are reality TV stars from shows including “The Bachelor,” “Big Brother” and “The Real Housewives of Beverly Hills.”The oldest contestant on the British version was in her 70s, and for many fans, it was refreshing to see a diversity of ages and backgrounds in a reality show.“We’ve all sort of been exhausted by the format of ‘Love Island’ and dating competitions where people are bronzed up and dressed to the nines,” Hamza Jahanzeb, a fan who ran a Twitter Space dedicated to “The Traitors,” said in a video interview. At 29, Jahanzeb is one of the show’s many viewers ages 16 to 34, and he said he felt the cast “was a reflection of our reality.”Mike Cotton, who is the executive producer of the British and American versions of the show, said in a video interview that this was intentional: “We always knew that we wanted to have a cast — have an eclectic cast — that represented a broad age range of people, much like you would get in a traditional murder mystery.”When it came to making the American version, producers at NBC decided to include reality TV regulars “to see if preconceived notions of known personalities would affect the game,” a representative from NBC said over email. Lambert noted that in the United States, a new show faced “even more competition than there is in Britain,” and that having recognizable faces among the first season’s contestants could be “helpful, in terms of getting attention and drawing an audience.”This mix of contestants also meant that “there was an added frisson,” Cumming said. The reality TV stars “were accused of being able to be more manipulative because they’ve done things like this before — in ‘Big Brother,’ in those shows where you have to kind of form alliances,” he said.“It’s kind of hilarious that the American version of the show is much camper than the British one,” Cumming said. Euan Cherry/PeacockWhile on the British show, it was “fascinating,” Cotton said, to see “how some people will become very convinced, 100 percent certain, someone is a traitor based on almost no evidence whatsoever,” in the U.S. version, a question that emerged for all contestants, including celebrities, was, “Can you sort of get rid of your preconceived notions about someone?”In both shows, if only Faithfuls remain at the end of the competition, the overall prize fund is split evenly between them. If a Traitor makes it to the end undiscovered, however, he or she takes all of the money.At a time when viewers often accuse reality shows of being overly produced and storyboarded, the producers on both versions of “The Traitors” had a deliberately hands-off approach to try to keep the gameplay feeling authentic and immersive.“We didn’t have the kind of reality show producers pulling people in for chats, chatting with people whilst they were taking a break or anything like that,” Cotton said.This lack of intrusion also added to the pressure cooker environment. On the British show, contestants “started talking about people as if they had actually died,” Cotton said. “And we just had to remind them that they hadn’t died, but were removed from the game.” The production team said that the show had a robust contestant welfare system, and an on-site psychologist.Cumming, who is touring his cabaret show in Australia, had never hosted a reality show before. He discussed with producers playing the host as a “James Bond villain,” he said, wearing tartan and a beret.It ended up being a “heightened sort of weird, dandy, Scottish, layered version of me,” he said. “It’s kind of hilarious that the American version of the show is much camper than the British one.”“But I guess that’s me,” he added. “That’s my fault.” More