NEW YORK — In “Nerve,” opening Wednesday, Emma Roberts plays Venus, a shy high school student who’s swept up as a “player” in an online game that involves escalating dares from anonymous “watchers” — leading to potentially life-threatening consequences.

The actress co-stars with Dave Franco as Ian, a mysterious fellow player who grows connected to Roberts’ newcomer.

In an interview with the stars at a hotel in Manhattan’s Chelsea, Franco says he personally has been “terrified forever about the internet — long before I ever heard about this movie.”

Roberts agrees.

“I find the internet to being definitely a frequently scary place,” she says. “But the thing about this movie is that, because of that fear, it keeps you on the edge of your seat. What I found fascinating was that this game of ‘Nerve’ didn’t feel that farfetched. You could believe that it totally exists.”

“Hey, maybe it does exist,” Franco says. “There probably is a version of this game out there that we don’t even know about.”

Or maybe after people see “Nerve,” even if such a game doesn’t already exist, someone will create one.

“Oh, my God, hopefully not!” Franco says.

In one especially edgy scene, Ian is dared to ride his motorcycle (with Venus on the back) and take it up to 60 miles an hour — while blindfolded. Acknowledging that the scene involved plenty of movie magic — special effects and stunt doubles — Roberts laughs about that late-night shoot.

“It was really fun, but, when I think back on it, I can’t believe that I did that in a sparkly, couture green mini-dress that supposedly cost nearly $4,000,” she says. “But at 4 a.m., when you’re on a movie set, you’re delirious. You’re like, ‘OK, I’m up for anything.’ Yet, the next day, I thought to myself, ‘I can’t believe I rode on that motorcycle.’ It was fun and a once-in-a-lifetime experience.”

Franco says, “Most of that scene we shot on a rig, but there’s a lot of shots there where Emma’s on the bike with the stunt driver. What was wild: He essentially was really driving with a blindfold over his face.”

Before signing on to star in “Nerve,” Franco says he’d never driven a motorcycle.

“I had about two weeks to learn to ride a bike, which is far less than you really want for something like this,” he says. “I had to put on that facade that I knew what I was doing so that you” — he turns Roberts — “would get back on the motorcycle with me.”

Roberts: “When we finished that scene, Dave said, ‘I was so nervous.’ And I said, ‘You were? Thanks for not telling me before I got on the back of that bike!’ ”

Another memorable moment was when Roberts and Franco had to strip down to their underwear to escape famed, tony New York store Bergdorf-Goodman. The setup: Both Venus’ and Ian’s own clothes had been stolen while they were dared by “watchers” to try on expensive formalwear. If they ran out of the store in the pricy outfits, they risked being arrested for shoplifting.

Even though that scene was filmed in the middle of the night, after Bergdorf’s was closed, Roberts and Franco say it still was intimidating to run around wearing only revealing underwear in front of the crew and other actors.

“In the movie, you only see us like that for about two minutes,” Roberts says. “But you have to realize we were shooting for two nights. The director would yell, ‘Cut!’ And then we would rush to slip into robes.”

At this point, Roberts and Franco decide to throw the reporter interviewing them a dare — to momentarily become a “player,” as they were in “Nerve.”

My dare was simple but potentially risky. “We get to read your most recent text messages,” Roberts says, pulling a slip of paper with a proposed dare from a bowl.

As I nervously unlock my iPhone, Franco jokes, “It will be really funny — not to say REALLY embarrassing — if we find a text from you to a friend saying, ‘OMG! “Nerve” is the worst movie, and Emma Roberts and Dave Franco totally suck in it!’ ”

As the two actors peruse my recent texts, they seem almost disappointed to find nothing like that among my notes to friends and family.

“You know,” says Franco, “these texts are pretty boring.”