LOS ANGELES (Hollywood Reporter) - A first-time director’s first challenge is finding a screenplay.

Cast member Jesse Eisenberg attends the premiere of the film "Zombieland" in Los Angeles September 23, 2009. REUTERS/Phil McCarten

For writer-directors, that’s no big deal because they usually start out passionate about something they’ve written.

But for a first-time, non-writer director like Ruben Fleischer, whose “Zombieland” opened at No. 1 at the weekend box office in North America with $25 million, it can pose big problems. The action comedy stars Woody Harrelson and Jesse Eisenberg.

“I’ve tried writing a couple screenplays and they were all pretty horrible,” Fleischer told me.

For years he wanted to transition from making music videos and commercials to directing features. He’d read his way through a stack of material before his agent, UTA’s Jason Burns, sent him Rhett Reese and Paul Wernick’s script about two guys trying to survive in a world overrun by zombies.

“I’m lucky because I have a terrific agent who always believed in me and had a real sense of my taste and was very proactive as far as mailing scripts,” Fleischer said. “And I was pretty diligent about spending my free time reading so I could find a project that potentially fit.”

Actually, “Zombieland” wasn’t even supposed to be a movie. Reese and Wernick were developing it for television with producer Gavin Polone. “But it was too expensive to be a show or pilot,” Fleischer said. “So Gavin took it to Sony where he’s made several other movies and had a good relationship and asked if they wanted to develop it as a feature.”

Fleischer (on why he was hired): “They needed to figure out how to take it from being the first episode of a show that would naturally set up a series to making it a self-contained feature.”

The solution he came up with was setting the film in an amusement park that would be the destination for the dramatic thrust of the script. “So it became like their Walley World,” he pointed out, recalling the theme park in 1983’s “National Lampoon’s Vacation.”

What attracted him to the script? “I’ve got to be honest -- at first I wasn’t interested because of the zombie nature of it. I’m just not a horror guy in any way. It actually put me off because I never envisioned making a zombie movie.”

Then he reread it and realized the undeads were just window-dressing, that it was really a buddy road movie with two very opposite characters.

“Every road movie needs a destination, and the television script was aimless because they wanted to sustain over multiple seasons survivors making their way through this apocalyptic landscape. But as a movie, we needed to give it an ending. So we came up with this climactic ending in an amusement park that was really cool.”

Fleischer had a budget of $22 million and a 41-day shooting schedule spanning February through April in Georgia, where he received significant tax incentives.

He said he saw Harrelson in the lead role from the start. “There’s something about the way he talks that is funny,” he added. “I wanted the character to be iconic and bigger than a typical zombie movie might have.”

Moreover, “He has all the qualities required of a bad-ass, zombie-killing, loner-drifter weirdo.”

In person, Harrelson even seemed a bit of a weirdo.

Fleischer met with him about “Zombieland” in New York at a vegan restaurant on Memorial Day weekend last year. “I was super nervous,” he said.

Enter Harrelson -- on roller blades and ripped jeans. He’d fallen in Central Park while skating over from his hotel. On the way he had gotten lost and had to ask for directions.

Fleischer (shaking his head): “I was trying to picture being a tourist in New York City and walking through Central Park when all of a sudden Woody Harrelson falls on roller blades in front of you and asks for directions.”

Harrelson liked Fleischer and the script but insisted on four things before going ahead. “The first two were fairly reasonable about casting and crew. The third was that we have an environmentally conscious set. And the fourth was that I don’t eat dairy for a week.”

It was an offer Fleischer couldn’t refuse: “For me to not eat cheese is like for an alcoholic not to drink. I had a hard time, especially since it was Memorial Day when he asked me and there were all the summer barbecues. But I ended up being a vegetarian for 11 months as a result.”