Until a few short years ago, many in the movie industry thought the comedy genre was squarely in the realm of the PG-13 rating, at the risk of excluding too much of an audience otherwise. Judd Apatow, though, changed things with his release of “The 40 Year Old Virgin,” which showed that comedy audiences can grow up, ironically enough when the screen is populated with childish men.

Since then, Apatow has gone on a comedy spree, and while not all of them set the box office on fire – “Drillbit Taylor,” for instance, didn’t set any box office records – nearly all of them have a slightly adult plotline.

And now the latest entry, “Pineapple Express,” comes to us full of drug use, brutal violence and … more childish men.

The plot focuses on Seth Rogen as Dale Denton, a 25-year-old process server with a high school girlfriend and a drug dealer buddy Saul, played by James Franco. When Dale becomes a witness to a murder, he and Saul end up running for their lives and trying – through their marijuana haze – to figure out the details of the war they become embroiled in and take steps to fight back.

And what a haze it is: Marijuana is the device that puts Dale and Saul in their predicament, gives them the courage to fight it and is very nearly the subject of every joke in the movie. And yet, nearly every character has belly laugh-inducing lines and delivery. Maybe weed does make everything funnier.

While Rogen is the first name on the bill, Franco – best known as Harry Osborn from “Spiderman” – steals nearly every scene he is in with his stoner ramblings. It’s almost as if he was locked up and not let out to do a scene unless he was completely baked. Who else would suggest, as an idea for a course of action when fleeing a drug ring, “smashing our cell phones and Quiznos?” When together, the duo’s back-and-forth banter emulates the Mary Jane Royalty – Cheech and Chong – better than one might think.

The only problem is, as running from fear transitions into stoners with guns, the movie slides a little bit. The action scenes are brutally violent and pull the same stunt that “Get Smart” tried earlier this summer: Violence for the sake of laughter. Granted, it’s less of a problem here – “Smart” was trashing a legacy while “Pineapple” doesn’t have a legacy – but still, the brutality tiptoes on the line of excess.

But while the movie may not know whether it wants to be a drug comedy or an action flick, one thing it does know is how to bring forth laughs. The flick is fun even for those who may not know what a roach is, but for those select few, some of the humor may be high over their heads.

4 * (out of 5)