After this weekend, there'll be a new standard for the archetypal party girl thanks to Alexis Knapp. The 22 year-old actress stars in rager Project X the popular high school girl who the film's protagonist, Thomas Mann, tries to impress by throwing the most epic party ever. The movie, out today, is Knapp's first lead role in a feature film and it's bound to catapult her into the limelight as one to watch. Here's everything you need to know about her.