Four pals—a nice guy, a scumball, a braggart, a wimp—get into trouble on a bachelor-party jaunt to Las Vegas. Director Todd Phillips and writers Jon Lucas and Scott Moore have excreted a loathsome fiasco that belongs on the shortlist of the worst movies ever made. They may have been aiming for the profane but genially perceptive ribaldry of a Judd Apatow or Kevin Smith, but even that modest target is out of their range. They achieve only ugliness—child abuse, elder abuse, racism, sexism, homophobia, in random and gratuitous spurts. As for the cast, it would be unkind to identify them. They seem to be doing their best, and they didn’t write this garbage. Actors can’t always pick their roles, so let them remain nameless. They’ve been through enough, and they deserve a chance to live it down.