Imagine a frat party thrown by the kind of guys who never rushed a frat (due to prior theater and D&D commitments), and you're halfway to embracing the ethos of Club Dread and its snarkitects, the Broken Lizard comedy troupe (2001's ''Super Troopers''). Going the rest of the way depends on your taste for the sort of slack, salty, sporadically ingenious humor you might find at your local improv hole for half the cost of a movie ticket.
''Suck straight from the coconut's teat,'' sings Coconut Pete (Bill Paxton), a Jimmy Buffet-like beach crooner who claims a certain ''son of a son of a bitch'' stole his image. To sustain his rummy memories of '70s celebrity, Pete runs a Costa Rican island resort that makes ''The Real Cancun'' look like Provo. The kids are happily drinking and bed-hopping -- until the hardbodies start hitting the floor. Everyone's a suspect, from mystic masseur Lars (Kevin Heffernan) to tennis pro Putman (director-cowriter Jay Chandrasekhar) -- and even as a joke, that gets tiresome. Yes, overabundant red herrings are a hallmark of the scary-movie parody (now, apparently, its own genre), but there are more characters than jokes here. A few gags are brilliantly staged, but most have a smug, collegiate take-it-or-leave-it quality that makes full-on belly laughter feel optional.