Pretending to warn us of online dangers, “Nerve” succeeds mainly in showing us how exhilarating it can be to embrace them.  Adapting Jeanne Ryan’s 2012 young-adult novel of the same name, the directors, Henry Joost and Ariel Schulman, return to the topic that provoked their 2010 documentary, “Catfish”: the seductiveness and malleability of internet identity.  For Vee (Emma Roberts), a shy high-school senior longing to escape her Staten Island home, a livelier, bolder self seems just the ticket. So when a friend introduces her to a real-time game app in which Players accept dares from Watchers to win cash, Vee is soon on board. It helps that her first task is to kiss a stranger, and that he’s played by Dave Franco.  A preview of the film.  The Watchers love them, offering dares of increasing recklessness and remuneration until the two realize they are trapped. The details of this are sketchy — apparently, people who can anonymously fill your bank account can also drain it — but the larger problem is a screenplay that amounts to little more than a string of flashy stunts before fizzling to a contrived close.  For all its hints at imminent catastrophe, “Nerve” feels surprisingly tame. Juliette Lewis appears briefly as Vee’s spectacularly clueless mother, and the endearing young actor Miles Heizer (so perfectly awkward in NBC’s “Parenthood”) is forced to play Vee’s best friend mostly from inside a car.  Internet personalities, like the Instagram comic Josh Ostrovsky, fail to fill in the blanks where real actors should be, but an unusually wide-ranging soundtrack — Wu-Tang Clan and Benny Mardones! — offers spot-that-tune distraction. “Nerve” might have nothing novel to say about the internet, but if it spikes downloads of Roy Orbison’s “You Got It,” who can complain?  “Nerve” is rated PG-13 (Parents strongly cautioned). Don’t see it if you’re afraid of heights, speeding motorcycles or bare bottoms. Running time: 1 hour 36 minutes.  Directors Henry Joost, Ariel Schulman  Writers Jeanne Ryan, Jessica Sharzer  Stars Emma Roberts, Dave Franco, Emily Meade, Miles Heizer, Kimiko Glenn  A version of this review appears in print on July 27, 2016, on page C6 of the New York edition with the headline: Players Acting Out the Dares of Watchers. Order Reprints| Today's Paper|Subscribe
Tired of playing it safe, a high-school senior joins a reality-style online game that soon escalates into dangerous stunts.