Andy Richter has a great scene at the beginning of “Scary Movie 2.” Playing sing-a-longs on a piano to a cocktail party of wealthy fifty- and sixty-year olds, Richter starts into Mystikal’s “Shake Ya Ass” and the party follows without missing a beat. “Funny because it’s absurd” seemed the motto to Richter’s work on “Late Night with Conan O’Brien,” and before him, Keenan Ivory Wayans’ work on “In Living Color.” These roots are important because the few good moments of “Scary Movie 2” are funny because they’re absurd; those moments that are bad, and there are too many to recommend the movie, are bad because they believe the scene is “funny because he looks like that,” or “funny because a parrot said it,” or “funny because so much came out.”

To review: “Scary Movie” was a spoof of the “Scream” series, which was itself a self-reflecting homage to director Wes Craven’s earlier schlock horror films. The success of “Scream” spawned a line of teen-age slasher films that were ripe for a spoof like “Scary Movie.” But a sequel to such a spoof takes the bite out the satire and franchises weak stereotypes and plot devices like the movies it teases. It’s the pot calling the kettle black.

For example,”Scary Movie 2″ brings back the cast of the original, now in college, and puts them in a haunted house for a weekend. But it skips the joke. “Scary Movie 2” is just as tired as the movies it spoofs. Both need the characters in the haunted mansion as soon as possible so the jokes/death can start. Nevermind how to get the characters there; the writers sure didn’t.

Movies spoofed include “What Lies Beneath,” “The Haunting,” “The Exorcist,” and movies beyond the young audience’s generation, such as “Poltergeist.”

David Cross and Chris Elliot have the most fun with their roles. Cross plays a wheelchair-bound teaching assistant, Elliott the mansion’s deformed caretaker. The two almost come out of their roles in a scene where they mock each other’s disabilities, but much of this is low-key and hardly offensive compared with the leaps in disabled humor made by the television show “South Park.”

But below the characters and the story are just a bunch of dirty jokes. Humor pours or explodes from the orifice of every character. James Woods has a scene at the beginning of the movie that ups the ante for scenes on a toilet, formerly set by “Dumb and Dumber” and “Trainspotting.” Woods’ role was written for Marlon Brando, who backed out of the part. Brando might have saved the scene. Seeing Woods humiliated on screen is nothing new to anyone who saw “The Specialist.”

“Scary Movie 2” has some smart in-references to horror films. When the spooked teens decide to split up, it’s the three blacks teens who are left to fend for themselves. Better is a scene where a girl wishes her friend killed by the ghost so as to keep safe.

But it’s not enough. “Scary Movie 2” falls prey to more dull scenes than it mocks, and even its spoofs seem uneven and uninspired. Everything is fair game. Jokes about Firestone tires and Monica Lewinsky’s blue dress are stale. In one sequence, characters dribble basketballs to spoof the recent Nike commercials.

But the commercials are good; the effort to spoof them is unnecessary, like most of the humor in “Scary Movie 2.”