From PEOPLE Magazine Click to enlarge
Jennifer Lawrence is still days away from seeing her life-changing role as Katniss Everdeen in The Hunger Games hit big screens worldwide on March 23, but already she has a newfound empathy for Justin Timberlake. The 21-year-old veteran of 2010's grim drama Winter's Bone and 2011's superhero blockbuster X-Men: First Class spent much of early March engulfed in a tidal wave of ear-splitting fan passion during a mall tour to promote the film. "I did indies and I was in X-Men, but that was a franchise that I just joined at the end," says Lawrence. "This is like 'N Sync. This is crazy."

And it's only just begun. What started out as a young-adult trilogy by author Suzanne Collins has blown up into the most obsessed-about pop-culture phenomenon since another trilogy-girl meets vampire, remember?-ignited similarly feverish fandemonium. With more than 26 million copies of the books in print and tracking surveys pegging ticket sales at a $100 million opening weekend, The Hunger Games is poised to catch fire in a big way. (By comparison, the first Twilight film made $69 million on its opening weekend.) Some 400 people camped out for almost two days outside L.A.'s Nokia Theatre to get a front-row perch at the Games premiere on March 12, joined by thousands more whose deafening roars left the cast overwhelmed. "It's hitting me right in the face," declared costar Liam Hemsworth, 22. "It's like a good punch to the head." Inside the screening, fans tweeted praise such as "so emotional" and "just amazing." Added 25-year-old Michelle Lindsley, who was No. 18 in line for the premiere: "We drove 12 hours from Utah just for this, because Hunger Games is awesome."

Set in the postapocalyptic country of Panem, the story introduces 16-year-old heroine Katniss, who is forced to compete in the totalitarian regime's sadistic Hunger Games-part gladiator-style death match, part televised extravaganza. Like the Twilight series, The Hunger Games features a love triangle between three sexy young stars: Lawrence; Josh Hutcherson, 19, who plays her Games competitor Peeta; and Hemsworth as Gale, Katniss's childhood best friend. Unlike in Twilight, however, the romance takes a backseat to themes of loyalty, oppression and the sinister undertones of today's reality-TV culture. "There's no schoolgirl crush happening here," says costar Elizabeth Banks, who plays government official Effie Trinket. "The stakes are too high for that. This isn't about a first kiss. This is life and death."

For the stars, shooting the film in North Carolina for three months last spring was considerably more fun. "It was like some weird summer camp," says Lawrence, who bonded with her leading men. "One day we went down to a creek to catch a crawdad, 'cause Liam didn't know what it was," recalls the actress, herself a "gorgeous tomboy," as casting director Debra Zane puts it. "I saw one and was like, 'Catch it!' Josh did and it got stuck to his hand. It was a leech! Then we went to Wal-Mart and bought slingshots."

After hours, the eclectic cast-which also includes rocker Lenny Kravitz as kindly Games stylist Cinna and Woody Harrelson as drunken mentor Haymitch-would often unwind in Kravitz's hotel room, where he would treat them to impromptu concerts. "I was hanging out in Lenny's place, and I ordered $500 on room service of just gummy bears without realizing it," says Lawrence, who costarred with Kravitz's daughter Zoe in X-Men: First Class. "He was saying to Zoe, 'Have you guys been ordering a ton of room service?' And it was like, 'No! What are you talking about?' And then the crystal bowl appears filled with gummy bears. It must have been like 10 bags' worth. I eat candy like a child."

But it wasn't all goofing around. In addition to animal encounters-Hutcherson was confronted by a bear during filming, and wild turkeys were a persistent nuisance on the set-the cast and crew also had to contend with the area's soaring heat. "It was 100 percent humidity with no rain. I didn't even know that could happen," says Lawrence, whose intense training regimen included hot yoga, freestyle running and shooting 100 arrows a day with an Olympic archery medalist to hone Katniss's skill with a bow and arrow. "Often in the film, you see Jennifer 80 feet up a tree-obviously on a safety harness," says director Gary Ross (Seabiscuit). "But how did she get in the tree? She climbed the freaking tree!" For his part, Hutcherson packed on 15 lbs. of muscle through strenuous workouts and eating "five giant meals a day" of chicken breasts and broccoli. "By the last meal, you're like, 'I can't even look at this chicken, but I have to eat it,'" he recalls. "But it worked."

Although fan reaction to the trio's casting was initially mixed-some fans complained that Lawrence was too old, Hutcherson too short and Hemsworth too blond-Zane says each star nailed their respective auditions. "The way I like to test it is, I like to turn the volume off [on the audition tapes], and then it's really real," says Zane. "You either believe it or you don't. The choices seemed very clear."

Ross is confident that his stars are prepared for the pressures of anchoring a megafranchise. "With Josh and Jen and Liam, I think they're more interested in acting than they are in being famous," he says. "I think all of the [mania] is a weird distraction to them. I think they're going to take care of their talent and work hard and turn into actors with a lot of depth and breadth."

Lawrence, who shares her character's disarming bluntness, is already feeling the pressure of meeting her fans' expectations. "I'm now a role model for young girls, so my language has had to change a lot," she says of curbing her cursing habit. And even if the full power of her stardom "still hasn't sunken in," it's beginning to. "I was doing press in Mexico a couple of weeks ago, and there was a Six Flags," she recalls. "I got them to turn on one of the roller coasters [for me]. And then yesterday we were driving by Sprinkles [in L.A.], and the line was too long. My security guard almost went in and got me a cupcake. It wasn't until I was in the car about to get a free Sprinkles cupcake that I was like, 'Oh, my God. Look at my life.'" She'd better hang on tight for the ride.

  • Contributors:
  • With Jessica Wedemeyer/L.A.,
  • Melody Chiu/L.A.,
  • Scott Huver/L.A.,
  • Blaine Zuckerman/L.A.,
  • Catherine Kast/N.Y.C..