In the case against such wannabe-funny efforts, the evidence speaks for itself. Caddyshack II. Meatballs Part II. Porky's II: The Next Day. Police Academy 2: Their First Assignment. Fletch Lives. Revenge of the Nerds II: Nerds in Paradise. Teen Wolf Too. Bill and Ted's Bogus Journey. Ace Ventura: When Nature Calls. Major League II. City Slickers II: The Legend of Curly's Gold. Dumb and Dumberer: When Harry Met Lloyd. Clerks II. Blues Brothers 2000. Legally Blonde 2: Red, White & Blonde. Evan Almighty. That's just a sampling of the innumerable examples that populate the annals of cinema history—and doesn't even include the dregs of action-comedy sequels (Beverly Hills Cop II, Another 48 Hours, or Ghostbusters 2, anyone? No?).

Of course, most sequels of any kind are terrible largely because the safest route to roping in audiences is to regurgitate. For the same reason that theatrical trailers give away almost all of a film's plot, sequels rehash because—to make a generalization that, of course, isn't true for all moviegoers—viewers are most comfortable when they recognize conventions and are thus prepared for their entertainment's forthcoming action, jokes, or twists. There's no commercial justification for a subsequent comedy work to venture out in a new, innovative direction, because the chances of striking humorous gold a second time remain low and because audiences are less likely to go to a theater if they think they'll be denied what they originally liked. Those same viewers almost always come away from such double-dips disappointed, but so long as the box office receipts keep churning, the sequel mill keeps turning.

To be fair, there exist a few scattered exceptions. A Very Harold and Kumar 3D Christmas bests both of its counterparts by separating itself from product placement shilling and faux-political nonsense; Chevy Chase's European Vacation and Christmas Vacation are far from embarrassments; and Naked Gun 2 ½: The Smell of Fear is, if not better than the maiden Naked Gun feature, just about on par with it, if only because it continues the grand tradition of watching O.J. Simpson suffer indignity after indignity (including multiple objects to the crotch). In the latter's case, the film's underlying form was also a factor in its favor. That's because comedies predicated on non-sequitur absurdity, untethered to any overarching concept or continuing narrative, find themselves in a better position to concoct inspired ridiculousness. If you're just throwing gags at the wall, it doesn't really matter if it's the first, second, or third time; what counts is that the gags stick.

Even so, Airplane II, Naked Gun 33 1/3, Hot Shots! Part Deux, and the inglorious Scary Movies (which double as not just the nadir of comedy sequels, but of cinema itself) undercut even that mildly hopeful suggestion. And this July's Grown Ups 2, which a more optimistic soul than I might say holds an inkling of promise simply because its predecessor contained absolutely no humor at all, seems unlikely to buck this trend. While The Hangover franchise proves that "high-concept" comedies are by definition one-shot deals—a fact also proven by Weekend at Bernie's II, whose very existence (they're still carrying around that dead body?!?) defies logic—there's no higher success rate for "low-concept" comedy follow-ups either. Ultimately, a great joke is only truly funny the first time; every successive retelling, no matter how it's been embellished with bigger budgets and amplified bizarreness, is destined for diminished returns. Which is another way of saying—the pressure's on, Anchorman II.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.