It's a tradition older than The Land Before Time II – building direct-to-DVD franchises on the foundations laid by popular originals, including blockbuster titles like Home Alone, Ace Ventura and Bambi.

More often than not, these sequels can claim only the most tenuous links to their predecessors, generally in the form of a common co-star or production team. (American Psycho 2, directed by Morgan J. Freeman – no, not that Morgan Freeman – and starring Mila Kunis and William Shatner in lieu of Christian Bale and Willem Dafoe, boasted the latter, but still managed to miss the point of the Bret Easton Ellis-inspired original by a country mile.) And they're cost-efficient, made on the cheap and capable of turning fast, substantial profits on name recognition alone.

In other words, they're a studio's dream, which explains why Warner Brothers, Paramount and Universal, among others, are committed to releasing more of them each year, including rumored sequels to Grease, The Naked Gun, Mean Girls and The Bad News Bears. Are they worth your time and money? Maybe, maybe not. But if direct-to-DVD sequels illustrate anything, it is all too frequently the law of diminishing returns.

American Pie Presents: The Book of Love
What is Eugene Levy still doing here? Let's not begrudge the venerable SCTV vet a paying gig, especially with Christopher Guest seemingly on hiatus from directing, but with this series sputtering to its 10th anniversary with a sixth sequel, his continued presence seems close to shameless. Full disclosure: I've never had an appetite for American Pie, even the well-received '99 original, but at least The Book of Love is a return to roots, sorta. Screenwriter David Steinberg (American Pie 2) returns as well, delivering tired but otherwise harmless gags about teenage boys in heat, one of whom makes love to a peanut-butter sandwich before the family dog lends a helping tongue.

Lost Boys: The Tribe
I've got a fever, and the only prescription is... more Corey? Fueled by A&E's hilarious documentation of Corey Feldman and Corey Haim's combustible friendship, their long-awaited reunion in The Tribe was elevated to must-see status. The only problem? Feldman's not in it enough, and Haim's not in it at all. (To be fair, he appears for a split second in the movie's final shot.) Instead, we get Kiefer Sutherland's half-brother Angus, who inherited father Donald's famous surname but none of his on-screen charisma, as a voracious vamp terrorizing the new kids in town. In all, The Tribe has the makings of a passable sequel – a diverting plot, a sprinkling of new ideas – but too little of the black humor that distinguished Joel Schumacher's original. No matter. The movie made back its $5 million budget within three weeks of its release, paving the way for a more Corey-ful follow-up: The Thirst, due later this year.

S. Darko: A Donnie Darko Tale
Richard Kelly's cult classic Donnie Darko, originally set for straight-to-DVD release until Newmarket Films stepped in with a more ambitious distribution plan, was a consummate work of the director's fertile (some might say overactive) imagination. Though it didn't seem to invite a follow-up, the possibility was intriguing enough. Could Donnie's younger sister (Daveigh Chase), haunted by the same apocalyptic premonitions that once prompted her brother to burn down his high school, carry a sequel? Perhaps, but not this one. Give director Chris Fisher some small credit: S. Darko faithfully replicates the look and feel of its predecessor, and the supporting cast, featuring Ed Westwick (TV's Gossip Girl) and the always reliable John Hawkes (HBO's Deadwood, Eastbound & Down), is solid. But this Donnie Darko Tale is all style, no substance – a superficial imitation that retraces the original's twists and turns but offers none of its own.

Smokin' Aces 2: Assassins' Ball
The premise of P. J. Pesce's prequel to director Joe Carnahan's 2006 original – itself a forgettable, testosterone-fueled fantasy inspired by Tarantino but lacking his wit and cinematic flair – is the same as before, but this is a movie less interested in breaking new ground than in coming up with the coolest kill scenes. On that level, it gets old quickly, though give Pesce some small credit for competently recreating the stylistic flourishes Carnahan (Narc) has made his calling card. Last time, we got Ryan Reynolds, Ray Liotta and Jeremy Piven as a hard-living magician run afoul of the mob; this time it's former footballer Vinnie Jones (The Midnight Meat Train) targeting a government spook played by Tom Berenger. But why split hairs?

WarGames: The Dead Code
WarGames, starring a 20-year-old Matthew Broderick, played skillfully on Cold War paranoia and fear of rapidly advancing technology. TheDead Code, released a quarter-century later, keeps the formula topical, replacing Soviet aggressors with cyber-savvy terrorists, but the renovations end there. An entirely new cast, blandly anchored by Matt Lanter (TV's Heroes) as a boyish computer whiz and Gary Reineke (Iron Eagle II) as legendary programmer Stephen Falken, gives Stuart Gillard's reverent rehash a pulse, but even fans of the original will find their attention wandering long before it's over.

Without a Paddle: Nature's Calling
Let's be honest. Based on a middling but amiably juvenile farce starring Seth Green, Matthew Lillard and Dax Shepard, there was no reason to expect anything more from Nature's Calling, in which a cast of relative unknowns serves up more of the same dick jokes and homosexual panic, played for laughs that come rarely if ever.

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