Margot Robbie: Beer got me through my new movie!

Margot Robbie, Chris Pine and Chiwetel Ejiofor had beer Fridays while filming Z for Zachariah.

The new movie tells the story of a love triangle in a post-apocalyptic time, where a disaster has wiped out most of civilisation.

The subject matter wasn't a light one, but the trio knew how to have fun on set.

"On Friday nights, we filled a bathtub with beers. We just hung out," Margot smiled to Us Weekly.

"Filming in New Zealand was extremely remote. We didn’t have phone reception, so it did really feel like we were living in a post-apocalyptic world."

The cast only consists of the three stars, so it was important they all got on. While one may envy Margot's time hanging out with the handsome actors, the Aussie says it was actually a furry co-star she bonded with most.

"[I bonded most with] Frosty, the dog in the film. We lived together! It was weird to leave set without him, but I liked not having dog food in my pockets," she laughed.

To play Anne Burden in the film, Margot sports long dark hair. The 25-year-old is better known for her blonde locks, but was happy to obey director Craig Zobel's brunette orders.

"I had just finished The Wolf of Wall Street and it was great to do something different. The director asked if I’d dye my hair, and I said, 'I’ll shave it off'," she revealed.

She's quickly gone back to blonde though, even adding pink and blue dip dyed ends to portray Harley Quinn in 2016 hotly anticipated Suicide Squad.