The writer-directors: Crossing the line with Todd Phillips

Filmmaker Todd Phillips, who directed “The Hangover” and its upcoming sequel, “The Hangover Part II” (which he also cowrote), has succeeded where any number of comic filmmakers have floundered: He brings cinematic gags to the very edge of acceptability, makes sure (through test screenings) that no one is overly insulted, and then takes the jokes one step further. “The audience inevitably tells me where the line is, and I end up two inches past it,” he says.

Other than a recent flap with the Motion Picture Assn. of America over a scene in the sequel’s trailer showing a monkey simulating a sex act (resulting in Warner Bros. pulling the preview), Phillips gets away with it in spectacular fashion. One of the most successful comedies in recent history (worldwide gross: more than $460 million), 2009’s “Hangover” managed to stitch together any number of sex, drug and fat jokes and not only offend very few but also make audiences care about its characters — including Alan (Zach Galifianakis), the guy with a restraining order to keep away from schools.

A few minutes after showing that monkey trailer to stunned exhibitors at a Las Vegas convention of movie theater owners in April, the 40-year-old Phillips explained his formula for raunchy comedy, saying it was as easy as the difference between “Borat” and “Bruno.” The director said that he’s equally enamored with Sacha Baron Cohen’s two movies, but that in the first film the joke is on Cohen’s character, while in the second it’s on his victims.

“Our guys are always the biggest victims in our movies — that’s the key. They are their own worst enemies,” says Phillips, who also directed “Old School” and “Due Date.” At the same time, Phillips says, you can help audiences stretch their comic sensibilities if you give them people they care about, and put them in relationships with likable friends. “If you can invest a little emotion in your characters, you can go so much further, because the audience is invested in real people,” Phillips says.

When the filmmaker was preparing “Due Date,” Phillips was warned by studio executives that the character played by Robert Downey Jr. couldn’t punch a little kid (even an obnoxious one) — the audience would never forgive him. But Phillips ignored their note, convinced that moviegoers would be rooting for Downey to do exactly what he did — and the laughs inside theaters proved he was right.

Sometimes, Phillips slips in jokes so crude that you don’t fully realize what you’ve seen until it’s too late to be uncomfortable, as he did in the graphic photo montage at the end of “The Hangover” (he promises more in the sequel, which opens May 26). “They go by so fast, I think we confused the powers that be. And you’re allowed to do more with photos. They insinuate, where live action shows.”

But no matter how far Phillips wants to push his comedy, the ticket buyers (after the actors) have the last say. “If you go too far,” he says, “you turn the audience off.”

john.horn@latimes.com