The best horror movies chase the same insidious ideal: to come up with new ways to scare moviegoers right out of their seats.

Directors shake their brains with fresh methods of frightening grownups into covering their eyes from what unfolds onscreen. The terror roll call: 1976’s “The Omen,” 1980’s “The Shining,” 1982’s “Poltergeist,” 1998’s original “Ringu” from Japan, 1999’s “The Blair Witch Project,” 2002’s “Ju-on: The Grudge,” 2007’s “[Rec]” from Spain, and, perhaps the scariest of them all, 1973’s “The Exorcist.”

The cutting edge (pun intended) of horror moviemakers continues to plunge into the depths to bring fear into the hearts of cynical, seen-it-all audiences. But sometimes, the best way is to take a horror classic and then amp up the scare level as high as it will go.

This is what James Wan, the director of “Insidious” and “Saw,” does with “The Conjuring.” He takes the familiar conceit of the haunted house and then uses everything in his arsenal to shock the hell out of any audience.

Paranormal investigator

“The Conjuring” benefits from having real-world connections. The film is based on the real-life experiences of paranormal investigator Ed Warren (“Insidious” star Patrick Wilson) and clairvoyant wife Lorraine (Vera Farmiga from TV’s “Bates Motel”), who later famously investigated what would be known as the Amityville house.

In 1971, Roger and Carolyn Perron (Ron Livingston and Lili Taylor, respectively) happily move their five daughters into an old house in Rhode Island, what they believe to be a dream home of their own. But their idyllic stay is immediately interrupted by unexplained events. The Perrons shrug it off, but the events not only continue, but increase in their intensity and nature.

When they are shaken to their core, the Perrons plead with the Warrens to help them. “There’s something happening in my house,” Carolyn says.

Reluctantly, the Warrens agree and travel to the Perron home. They realize right away something’s not right. “Something’s definitely here,” Lorraine warns.

So, that’s it, right? The investigators come and solve everything and the Perrons live happily ever after?

That’s what would happen in any other horror movie, but not this one. That was just the first part of “The Conjuring”—the rest of the movie is spent not only dealing with the malevolent spirits in the house, but even what happens after that.

Demonic activity

It’s like Wan decided to show you what happens when a paranormal investigation doesn’t go the way it’s supposed to—and the Warrens aren’t quite sure they can handle it.

“The three stages of demonic activity are infestation, oppression and possession,” says Ed Warren, and all three are present and accounted for.

Horror films usually use either the now-you-see-me, now-you-don’t spookiness of atmosphere, or the outright “booo!” school of revelation. Wan wisely uses the first to slip into the second, with the actual horror still being there when you open your eyes.

He expands on the storytelling to include the tragic and horrifying things that happened there before the Perrons arrived.

What makes “The Conjuring” so frightening is that it takes what you already expect from horror films and then goes into “I-can’t-believe-he-went-there” territory. There are the usual spooky shenanigans—objects moving by themselves, mysterious noises, doors opening—but then Wan dares to go into more alarming fare. It will forever change the way you look at the game of hide-and-seek.

Annabelle

There is a terrifying possession in this movie that will certainly leave an impression, as well as a new doll to add to the roster of famous horror movie dolls (Chucky, meet Anabelle).

So, take the proper precautions: Don’t watch the movie alone, avoid cellars, keep the lights on and try to be asleep by 3 a.m.

There are several reasons why “The Conjuring” broke box-office records when it opened in the United States in July. Helping Wan do this are the over-the-top score by Joseph Bishara and the accurate costumes by Kristin Burke (you will swear it’s really the 1970s).

Though it is built on classic horror tropes, “The Conjuring” is in reality a very modern movie in a period setting, with director Wan maximizing contemporary techniques to strike fear into the hearts of moviegoers.

Aided by all that and the verisimilitude offered by the Warrens’ files, “The Conjuring” is the most terrifying movie to come a-haunting in a while. Consider yourselves properly warned—and invited.

Warner Bros’ “The Conjuring” will have sneak peeks in selected cinemas on Aug. 12 and 13, before opening wide on Aug. 21.