Another week, another Apatow movie. Another Apatow movie, another story of lame, pot-smoking slackers up to all kinds of hijinks and discovering the true meaning of friendship.

Sigh.

Comedy is often grounded in the pleasure of seeing someone get away with bad behavior we are not allowed to enjoy or seeing someone safely other than ourselves squirm through a nightmare scenario of humiliation and failure. This kind of comedy has an essential and revelatory childishness that reminds us, sitting comfortably in our stadium seating, how fine the line is between how we try to appear and what we are really thinking.

But whether that is slapstick like the Three Stooges bashing each other or outrageous behavior like Howard Stern’s radio show, there has to be something that keeps us on the side of the anti-heroes and this movie runs out of goodwill long before the finish. In The 40-Year-Old Virgin the leading man was a decent guy who just somehow missed one of the essential off-ramps to adulthood. In Superbad we get to witness one of those efforts to make it to the off-ramp as it happens. Adolescent behavior is expected when the characters are actual adolescents. But in this movie, most of the characters are unappealing, generic, and just too skeezy.

Except for James Franco. Casting directors take one look at those cheekbones and assign Franco to the brooding category. One of his early break-out roles was the broodiest of them all, the lead in a made-for-television biopic about James Dean. More recently, he smoldered his way through the “Spider-Man” movies as best friend/rival/nemesis Harry Osborn. Only Apatow saw Franco’s gifts as a comic actor and cast him in “Freaks and Geeks.”

As Saul, a sweetly stoned dealer who just wants to take care of his Bubbe, watch some television, and make some friends, he turns in one of the choicest comic performances of the year, making every moment about more than just being dim or baked. When he says that smoking the super-potent strain of marijuana that gives the film its name is almost like “killing a unicorn” or is happily reminded, when he says he’d like a job that involved hanging around and getting stoned all day that that is exactly the job he has, or when he unexpectedly finds the mental capacity to come up with an astounding list of possible ways that the bad guys might track them down, he gives us a character who is enchantingly caught up in a world of perpetual possibilities.

Seth Rogan, who co-wrote the script, is far less interesting as Dale, a 25-year-old process server with a high school girlfriend who is vastly more mature than he is. He can see that even through the constant cloud of marijuana smoke, and that only makes him more insecure and needy — and juvenile.

A vicious drug dealer (Gary Cole) and a corrupt cop (Rosie Perez) come after Dale and Saul, and various other people get caught up in the chase, including a fellow dealer whose loyalties are rather fluid (a funny Danny R. McBride). Extreme and graphic violence is interspersed with various stoner riffs and random encounters, including Bubbe’s assisted living facility and a surreal suburban family dinner with the parents of the high school girlfriend. Franco continues to find fresh ways to engage us but Perez and Cole are drastically underused and Rogan is as stale as last week’s bong water. It’s not outrageous enough, it’s not audacious enough, and it’s just not funny enough.