Seeing the need to bring the thrills of the zombie genre to TV, writers Rhett Reese and Paul Wernick hoped to launch "Zombieland" as a CBS pilot, but eventually settled on big screen adaption starring Woody Harrelson and Jesse Eisenberg.

"Zombieland" focuses on four people forced to rely on each other in a world overrun by zombies. As reluctant partners, they soon begin to wonder if it might be better to simply take their chances alone.

Reese and Wernick ("The Joe Schmo Show"), who also executive produced, navigated the project through a lengthy development.

"Coming off of reality TV, we wanted to sort of break in at sort of traditionally scripted stuff," Wernick said in a recent interview with /Film. "And we wrote it as a spec, feeling that the zombie genre had not really been tapped in the TV side. And we sold it to CBS. And went through a little bit of development at CBS, and we did not end up making the pilot. And it sat at Sony TV, who we had been partnered with on the project, for several years. And sort of with the passion of an executive at Sony TV, Chris Parnell, and Gavin Palone, our producer on the project, they sort of presented us the option of sort of turning it into a sort of a back-door pilot, sort of a made-for-TV movie, which we graciously jumped at.

"Extended it out from pilot form into movie. Which interestingly, the pilot pretty much stayed the same. The first 60 pages of the movie are pretty much the pilot script, interestingly. And the second 40 pages are pretty much episode two of the pilot script. Right?"

"Its really true, yeah," Reese said. "We did what we were going to do in episode two and put it in. No, that did change, because Ruben, when he turned it into a movie, wanted it to end really big, so we changed the third act to make it an amusement park and a big fight."

Early in the script development "Zombieland" actually caught the eye of horror master John Carpenter. Wernick said they "met with John Carpenter, who wanted to direct the pilot of 'Zombieland.' And then ultimately, it sort of transitioned into a feature and John Carpenter went away."

What stirred such interest in "Zombieland"?

"Thats tough. I think it brings a level of depth and emotion and humanity that you may not have seen in zombie movies before," Reese explained. "I also think its as funny as any zombie movie thats been done. I hesitate ever to say, theres so many classic zombie movies, great, great movies, so this is just slightly different. But its, I dont know, Im not objective. I think its pretty funny, its really, really funny. But I think this movie could bring a tear to peoples eye. Im not sure thats necessarily happened in a zombie movie before, but maybe it has. I dont know."

"We shot a scene yesterday that was just really emotional," Wernick added. "And its just the mixture of genre with comedy with heart and emotion, its sort of a delicate dance and I think its going to work."

Despite the developmental shifts necessary for crafting "Zombieland" as a feature film, Reese and Wernick are excited about the project's ultimate direction.

"Yeah, were really, really happy," Reese said. "Its sort of coming to life exactly as we pictured it. Theres certain things that are different than the very first incarnation, but largely its just this getting up every morning and getting a Chrsitmas gift. Youre looking at the tree and theres a new gift and it looks pretty much like what you wanted. Its really, really exciting."

Check out more of Reese and Wernick's interview at /Film.

"Zombieland" hits theaters Oct. 9.