LOS ANGELES - It took James Franco a decade to move from drama back to the genre that launched his career. It also took the prodding of Judd Apatow, who had shown the world that Franco could be funny, and a sacrifice, of sorts, by an old friend.

Franco, who won a Golden Globe, a Critics’ Choice Award, and an Emmy nomination for playing James Dean—and gained millions of fans through his work in three Spider-Man movies—started out in comedy with the Apatow-produced TV show Freaks and Geeks. It was there that he met Seth Rogen, who was 17 when he costarred in the series.

Rogen was so enthusiastic about the idea of working with Franco in the comedy Pineapple Express that he decided to give up the role that he had written for himself, with his writing partner Evan Goldberg. “We originally wrote Franco’s role for me,” Rogen says in a Los Angeles hotel room. “When we got Franco involved, we decided to switch the roles.”

The role Franco has in Pineapple Express, which opens August 7, is that of a dope dealer named Saul Silver who smokes most of his profits. Rogen plays Dale Denton, a customer who witnesses a murder committed by Silver’s supplier. When Saul and Dale conclude that the killer will come after them, they hit the road.

Franco says he missed comedy after 10 years of directing and acting in dramas. “I directed a low-budget movie that played at a festival in Austin and Judd was there and he said, ”˜I miss the funny Franco.’ Then he told me he was going to be directing a comedy called Knocked Up with Seth, and that after that Seth and I should do a movie together.

"I had always liked movies that weren’t stoner movies but had stoner characters—people like Spicoli in Fast Times at Ridgemont High or the Dude in The Big Lebowski or Brad Pitt’s character in True Romance. They are goofy guys but there is something more going on. I read the script for this movie and I liked the role of Saul and I said, ”˜I think Seth is going to play Saul, which I want to play.’ Judd said, ”˜No, you should play Saul,’ and Seth agreed.”

Rogen admits that although they have become friends over the years, the four-year age gap between Franco and other Freaks and Geeks cast members, including Rogen, kept the two actors from being close when they were shooting the series. “He didn’t hang out much with us. He was older and more mature. We would order steaks and sandwiches and he ordered chicken breasts and vegetables.”

Franco says that he missed working with Rogen, if only because the age difference between their characters allowed him to be the dispenser of wisdom. “There was one episode in Freaks and Seth’s character had a crush on a girl and he went and got advice from me. That was one of the cooler episodes for me, so that kind of dynamic was what I remember from the show.”