Parts of "Scary Movie 4" are funny, but there are prerequisites.

A scattershot parody of many films, not all of them scary ("Brokeback Mountain"), "Scary Movie 4" spends most of its time with "War of the Worlds," "The Grudge" and "The Village," and you won't be able to make anything of it if you haven't seen at least two of those three. You still might miss a joke here or there — the "Million Dollar Baby" bit, for instance — but at least you'll be in the right neighborhood.

Watching the movie is quite a bit like reading a slightly out-of-date Mad magazine or, I guess I should say, quite a bit like I remember Mad as a seventh-grader. Jokes pile on top of each other, and if some don't work, it's no biggie because you know there are 17 more in the wings. The movie is actually at its weakest when it parodies the horror cliches it already dispensed with in "Scary Movie 1," and strongest when it is, for instance, doing a clever "Saw" knockoff that depends on our knowledge of Shaquille O'Neal's inability to sink free throws.

The problem is that, after four "Scarys" and three "Screams," there's not much left to make fun of in slasher movies. But ripping on Tom Cruise, or a multimillionaire who can't do the most basic thing in his sport or a bratty kid who keeps pulling a Kenny from "South Park"? Some jokes are evergreens.