To make the romance work, Favreau needed to draw out the intelligence and charm of his leads, making sure they were playing heightened versions of themselves. In the comic books, Tony Stark doesn’t have much of a sense of humor, but Downey infused him with his own wit and wrapped the character in a blanket of sarcasm. Although Paltrow wasn’t as comfortable with improvisation as Downey, Favreau found a way to inject her personality into the script—he would jot down things Paltrow said during rehearsals and then repurpose them as Pepper’s dialogue.
