Though the experience seems new for every generation, teenagers have always faced hormonal chaos, romantic obsession, parental tyranny, peer pressure, crises of identity, and demons from another dimension. “Harry Potter,” “Twilight,” “The Hunger Games,” and others have dramatized this critical period to great success both in print and onscreen. For studios seeking another such franchise gold mine, Cassandra Clare’s “Mortal Instruments,” a hefty, best-selling sextet of YA novels, would seem the next big thing. Not only does it exploit the same demographic as those other properties, it shares swaths of their DNA. “All the stories are true,” goes a refrain in Clare’s book that is repeated in the film, and apparently they are also fair game for pillaging.
The trouble comes when these stories all take place at the same time. To her credit, Clare elevates a potential farrago into a nearly coherent, highly readable narrative. In the film, however, under the uninspired direction of Harald Zwart (his resume includes “Agent Cody Banks” and the 2010 “Karate Kid” remake), “The Mortal Instruments: City of Bones” plays like a “Scary Movie” parody.