03/19/2011 at 11:00 AM EDT
As the official leading lady of The Hunger Games
, Jennifer Lawrence knows she's landed an out-of-this-world role – in more ways than one.
Taking on the part of Katniss Everdeen, a fierce and feisty heroine competing in the ultimate game of life-or-death, Lawrence, 20, has extra special, extraterrestrial inspiration for tapping into the "fighting spirit" of her character.
"Sigourney Weaver's Ripley in Alien
is the first [movie] that comes to mind," she tells Entertainment Weekly
of an older yet similarly famous heroine.
And while she may not be kicking alien-butt in the adaptation of Suzanne Collins's beloved trilogy, Lawrence knows one thing: There's a lot of fans that will want to kick her
butt if she doesn't deliver.
"I have a huge responsibility to the fans of this incredible book, and I don't take it lightly," she said Friday. "I will give everything I have to these movies and to this role to make it worthy of Suzanne Collins's masterpiece."
But for fans of the book that are skeptical – perhaps about Lawrence's older age or head of blonde hair – Director Gary Ross tells EW
the choice was "the easiest casting decision I ever made in my life ... She came in and read for me, and it just knocked me out." Plus, he says, "we can easily deal with Jennifer's hair color."