Modern take on mythology

A youth learns by accident that he possesses extraordinary powers, is dispatched to a special academy for those of his kind, and undertakes a quest with his two best buds to defeat the dark powers. Luke Skywalker? Harry Potter? Guess again: Percy Jackson, archetypal hero for the modern, emo middle schooler.

Percy Jackson (Logan Lerman) is a loser. Because he has dyslexia, the question on the blackboard is too hard to decipher. Because he has ADHD, he can't focus. And because he has an abusive stepfather, Percy can't bear to be at home.

What Percy does not yet know is that he's also a demigod, spawn of Poseidon (Kevin McKidd) and a mortal (Catherine Keener). And that his best bud, Grover (Brandon T. Jackson), is really his protector. And that his real name is Perseus, after the rare classical hero whose saga does not end tragically.

As Percy has always felt best when swimming, it follows that Dad is the god of the sea. But no sooner does Percy learn his paternity than he finds himself accused of stealing Zeus' lightning bolt and sees his mother abducted, and possibly vaporized, by Hades, god of the Underworld.

Based on the young-adult series by Rick Riordan, Percy Jackson & the Olympians: The Lightning Thief, is a diverting action fantasy that modernizes the stories of demigods and monsters. (Riordan imagines the Greek gods as sparring siblings who sic their fanged pets on one another.) Like the mythical Perseus, Percy neutralizes Medusa, that babe with the nest-of-vipers coif, and flies around with the help of winged footwear - except here they are not sandals, but Converse high-tops.

Yet as brought to the screen by Chris Columbus, maker of the Home Alone movies and the first two Harry Potters, The Lightning Thief feels more like an audition to fill the franchise vacuum that will be left by the imminent end of the Potter series. The trio of lead actors, particularly Lerman as Percy, are agreeable. But the film is heavy with special-effects action and light on the playful humor that makes Riordan's books such a fun read. (Like hot peppers, special effects should be used sparingly, lest they dull the senses and overwhelm the dish. Percy Jackson suffers from effects overload.)

Lerman, Jackson (as Grover, a teen satyr desperate for his horns), and Alexandra Daddario (as Annabeth, Athena's butt-kicking illegitimate daughter) set out to clear Percy's name and reclaim his mom with tools apparently lifted from the Harry Potter prop master. Percy has a diagram, very much like Harry's Marauder's Map, that guides the trio across country to pearls that will be their get-out-of-Hades-free passes. (Although rated PG, the action violence and scary monsters might freak out those under 8.)

Like its stars, the film is genial good company. While it won't kill any brain cells, it is unlikely to enter the pantheon of epic screen adventures.

Contact movie critic Carrie Rickey at 215-854-5402 or crickey@phillynews.com. Read her blog, "Flickgrrl," at http://www.philly.com/philly/blogs/flickgrrl/.