'Truth or Dare': How a wicked smile became an unnerving horror treat

In the new horror film Truth or Dare, there's no Freddy or Jason, no masked killer, and no nutcase with an ax to grind — or even an ax to wield. Instead, the creepiest thing is a truly wicked grin.

Truth or Dare (in theaters Friday) takes the infamous party game and makes a killer thriller, with a bunch of college-age kids forced to play a deadly ongoing version after a curse is cast upon them while they're in Mexico for spring break. The rules: Each person takes turns being asked "Truth or dare?" — and if they lie, don't do the dare or simply refuse to participate, they die. And each turn involves bystanders or the player wearing a hideously wide, Joker-like grin.

"Yeah, it’s a horror movie and there are all the gory, jump-scare moments, but underneath it all, I thought it was really interesting that everyone in this movie is harboring a really dark secret," says star Lucy Hale.

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The unnerving grin passed among the characters is way more chilling than the movie's conventional fright-fest aspects. However, what scared director Jeff Wadlow the most was figuring out what or who his primary villain would be. "Even though the game of Truth or Dare is universally loved and people all seem to play it when coming of age, it's a weird game in that there are no stakes, no winner or loser, no defined length," the filmmaker says. After thinking about it, he came to the realization that "your friends become the antagonist."

He says there were multiple inspirations for the smile. Wadlow has doodled scary grins ever since high school; the game has a mischievous spirit, so he thought the mysterious evil force that possesses its victims should wear a smile rather than have the tired trope of milky or black eyes. Plus, the director was inspired by the way Snapchat filters alter the anatomy of people's faces: "I find that kind of disconcerting to look at."

The idea was broached of using prosthetics on his actors to find a disturbing-enough expression — think Heath Ledger or Jack Nicholson's iconic takes on the Joker. But "honestly, we didn't have the time," Wadlow says. "I can't be waiting around for people to go to a makeup chair."

So he decided to manipulate actors' real smiles, using visual effects in post-production to reach the perfect level of freakiness. Wadlow says Tyler Posey didn't need much tweaking — "We probably only augmented his smile by, like, 5%" — and neither did Hale, which is news to the actress. "I don’t know if I should be offended or flattered," she says, laughing.

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"I kind of look like that in real life," Hale adds. "I have abnormally big eyes and kind of a cartoony face anyway."

She allows that the grin was "actually extremely uncomfortable to film: You had to do your scene, say your dialogue, but your chin had to be all the way to your chest and you just had to smile as big as humanly possible."

Wadlow puts his smiley harbinger of doom into perfect perspective: "It almost has become the shark fin poking out of the water. When I watch the movie with audiences and the smile presents (itself), people go, 'Oooh,' and they know what's coming and get excited."