Mixing two genres as different as the zombie movie and the romantic comedy might seem too bizarre an idea to work, but “Shaun of the Dead,” the maiden feature by the team that made the sketch TV series “Spaced” a cult hit in England, defied the odds and became a smash in their home country, outgrossing the recent remake of its inspiration “Dawn of the Dead” in the process. Co-writers Simon Pegg and Edgar Wright, who also starred in and directed the picture respectively, visited Dallas recently on a promotional tour for the movie’s American release, and explained how “Shaun” came about.

“We have a sitcom in the U.K. called ‘Spaced,’” Pegg said, “and I wrote a scene for it in which my character Tim–a sort of comic-book shop geek, video game-playing skateboarder–is playing the original ‘Resident Evil,’ and he’s been playing it all night, and he ends up hallucinating that he’s in the game. And he has this little sequence where I’m battling some zombies, and after shooting all that morning doing that scene, myself and Edgar sort of turned to each other and said, ‘Wouldn’t it be great if we could actually make a zombie movie–and it not be a fantasy sequence or a flashback, it be actually happening?’ And that’s what inspired us to go on and write ‘Shaun.’”

Wright noted that the project fit right in with their interests. “Zombie films and monster films, and even more specifically than that the George Romero trilogy, are films that me and Simon [love],” he said. “‘Dawn of the Dead’ is one of our favorite films.” Watching it, he continued, made them think about “various end-of-the-world fantasies. It was both through doing that and maybe playing some of those ‘Resident Evil’ games that started off the idea–well, what would we do in that crisis? How would we react if there was a zombie in our back garden on a Sunday morning, and we had a hangover and we didn’t have a shotgun under the bed?”

But that was only the beginning. “Later came the idea of kind of crossbreeding the romantic comedy and the zombie film,” Wright added. “Initially, at least, the joke was because Britain’s main export in films is the romantic comedy, and we thought it would be funny to do a romantic comedy where most of the cast die in the end–which is what you want to see, really!”

Pegg and Wright wrote the parts mostly with certain actors in mind–including Ed, Shaun’s gross, slacker flatmate, which was always intended for Nick Frost, who was also on the tour. “He didn’t have any choice,” Pegg said. “I think at one point Simon threatened me with a box cutter [and said] ‘You’d better do it,” Frost explained. “Simon and I have been best friends for ten years. We were flatmates for seven of those years. So I’ve always been his Ed, in a way. But I was never an actor, I was a waiter–I never wanted to act or write. Then when Simon and Jessica [Stevenson] wrote ‘Spaced,’ they wrote a part just for me….So I said, ‘Yeah, I’ll have a go at acting.’ I couldn’t go on serving food for the rest of my life, so when the opportunity came along, I took it.” And as far as “Shaun” was concerned, Pegg added, “There was never any question that it’d be a vehicle for myself and Nick together.” The cast also included other old friends and colleagues–Kate Ashfield, from “Spaced,” as Shaun’s girlfriend Liz, and Peter Serafinowicz as his other roommate, the straightlaced yuppie Pete (“the complete opposite of that character,” Pegg noted). Some roles, however, went to people outside the show’s loop, including Bill Nighy as Shaun’s stepfather. “It wasn’t written for him but he was fantastic,” Wright said. “He was just totally into it, and completely got the joke.”

The zombies were a special case. “With the zombies we had about forty specialized extras or actors or stunt people or physical performers who were all kind of cast properly,” Wright said. “Then the rest of it was, we did literally like a cattle-call on the internet, on the website for our TV show–‘Does anybody want to be a zombie?’ We were completely honest about it. ‘We can’t really pay you, and it’s going to be long days, and you’d get to be a zombie in the film.’ And we had this enormous response–eleven hundred people. So we had, like, a zombie-idol audition process. And people really got into it. Some people would come back again and again–clearly didn’t have proper jobs. It was great. We really couldn’t have done it without them. The zombies actually took it very seriously–you’d see them zoning out as the camera started to roll. Sometimes it was really funny. A curious kind of mob mentality really takes over.”

Pegg, Wright and Frost hope that the same sort of enthusiasm will spill over into the American audience, just as it did in England. “Shaun of the Dead” has already exceeded expectations wildly, because, as Wright noted, “about 60% of the films made in Britain never get released.” For it to take off on this side of the Atlantic too would be a remarkable hat trick.