The Rum Diary star was among the celebrities taking part in the collaborative charity theatre project, which brings actors, writers and directors together to produce a play in just 24 hours.
However, Heard's turn on stage fell flat when she tripped over and hit the floor hard during her performance.
She quickly picked herself up and continued with the play, much to the amusement of Gangster Squad star Anthony Mackie, who tells New York Post gossip column Page Six, ""The (most fun) was watching Amber fall and almost kill herself. It was priceless.""
Heard adds to Elle.com, ""I broke in my Broadway chops... It was the Wild West of theatre. It felt like you were really shooting from the hip and trying to stay on the horse. Anyone who saw the show tonight will tell you that's exactly what I tried to do.""
Other stars who took part in this year's plays included Vanessa Hudgens, Olivia Wilde, Seth Green and Justin Long.