Margot Robbie was almost where she needed to be.

Prior to beginning filming on Suicide Squad, the Australian actress had just about completed her transformation into Harley Quinn.

In preparation for the role, she dived into online forums to find out what it was fans loved most about the popular DC Comics character, who's known as the Joker's psychotic girlfriend. She was given stacks of comic books to study, admitting she had no intention to read every one, but she did anyway.

But even then, there was one aspect of Harley Quinn that Robbie just didn't get: the Joker thing.


"I just didn't understand how she could be such a badass and then fall to pieces over some guy. I found that really frustrating," Robbie says. "Fans seem to really love that about her, that she has this complete devotion to a guy that treats her badly."

Robbie's acting coach recommended she read a play called Fool for Love, about a couple in an extremely dysfunctional relationship. She then found herself researching "co-dependence". "Once I could view it in those terms, it suddenly made sense, and I suddenly had so much empathy for Harley and after that it was all very straightforward," Robbie said. "It was fun after all that." Robbie spoke to The Washington Post about becoming Harley Quinn and her experiences while filming Suicide Squad.

When you saw the original Harley Quinn costume (from her cartoon debut), did you think, "Oh no, is that what I'm going to have to wear the entire movie?"

As I was reading all the comic books, she has tons of different outfits. In some comic books she's wearing more of like a corset and mini-shorts, and in some she's wearing the full jester outfit. I didn't really know what exactly the costume was going to be, but I knew if [director] David [Ayer] was making the movie and his films are always pretty grounded in reality, I kind of had a feeling we weren't going to be doing the polished comic book look. That we'd be doing something a little grittier, a little more street, a little more real.

This will be the first time fans get to see a live-action version of the Joker and Harley Quinn together. What was it like bringing that relationship to life?

It was like having front row seats to an incredible show. [Jared Leto's] so committed, and he really raises the bar. When he's playing the Joker, I don't know what he's going to do. We didn't do rehearsals. It was all very in the moment. We're meant to be unpredictable characters. So I think that energy was palpable on set and very fitting for the relationship.

How long did it take you to perfect your Harley Quinn voice? And was it hard filming in full makeup during those rain scenes?

Yeah. Not just the makeup, but the wig, the costume. It's not the most comfortable getup. And we're doing a lot of fight scenes and stuff. Actually, the worst thing were the gold bangles. They had spikes on them, and I'd always stab myself. I hated them.

The voice took a while because I knew it was something we'd have to commit to. It's really high pitched. It's really fun in that comic book heightened reality kind of way, but it's not very fitting for a David Ayer film. There's going to be a lot of dark, gritty, serious scenes.

Your character Harley Quinn and Will Smith's character, Deadshot, come off having great chemistry in the movie. You and Will have worked together before. Did that help a little bit to build a bond between your two characters in this film?

Totally. He's been in the industry so long and in the spotlight so long, he's someone I really look up to and as a friend I know he's there for me. It's really nice to be able to be at work and have that level of comfort with someone that knows you already and knows when you're upset. He's very intuitive in that way.

What was the more difficult scene to film, the car chase that ends up underwater or the transformation scene where you dive into the vat of chemicals to bleach your skin?

That chemical [scene] was the most unpleasant thing I've ever done in my entire life. So that was definitely my least favorite. It was like this gluggy paint stuff that was so far in my ears and up my nose, and I was choking on it underwater, and I couldn't breathe, and I tried to open my eyes, and it would glaze over my eyeballs, and I could only see white. It was horrible.

The underwater scene, with the car crashing into the water, that was my favorite because I got to work with a free-diving expert and learn how to hold my breath under water for a really long time. So that's like my new party trick.

What was it like the few times Ben Affleck was on the set as Batman?

It was really exciting. We were trying to keep it a secret for ages. Once the Batmobile was on the streets of Toronto, the cat was out of the bag.

Is it too soon to start thinking about Harley Quinn solo movies or are you going to be too busy because this clearly isn't going to be the last Suicide Squad film?

The DC universe is so vast, there's thousands of comics, there's hundreds more characters that have never been portrayed on screen. I just think there's so much more we can do, and I think it's worth exploring.

• Suicide Squad is screening now in New Zealand cinemas.