Mary Elizabeth Winstead plays Kate, who is struggling to quit drinking.

At first, “Smashed,” opening Friday, seems like it’s going to be a quirky indie rom-com about a married couple — elementary school teacher Kate (Mary Elizabeth Winstead) and Charlie (“Breaking Bad’s” Aaron Paul) — who like to drink. A lot. They rides bikes around Los Angeles drunk. They do drunk karaoke. They play drinking games.

One night, Kate gets drunk and smokes some crack. A few scenes later, she pees on the floor of a liquor store. The next morning, she realizes it’s time to get help.

Winstead gives a powerhouse performance as the damaged Kate — one that’s not always pretty.

How did you prepare for this role?
The first thing I did was spend a lot of time talking to alcoholics, specifically starting with our co-writer Susan Burke and one our producers, Elise Salomon, who is also in AA. They ended up taking me to a lot of AA meetings. The most important thing they did was make me realize how much I related to the stories in the room.

I assume you didn’t smoke crack?
Surprisingly, no. I thought about it and decided, “I’ll wing it.”

That’s the moment when, as a viewer, you realize this movie is not going to be a romantic comedy.
Reading scenes like that as an observer and a reader, it’s just exciting that you’re getting to an interesting part of the story. But then the actor side of me is freaking out: How on earth would I play that scene? It’s something so far beyond anything I’ve done before.

Some people play drunk and go way over the top. How did you approach the scenes where you had to act sloppy?
I’ve never played drunk before. [Director] James [Ponsoldt and I] pored over this book “The Power of the Actor.” There’s an entire chapter dedicated to playing drunk, so I studied that. I did other physical things, like spinning around so the room would always be spinning. It was a nice balance of feeling not quite like myself, feeling a little woozy and out of it, but still being in my body enough to know where I was and what I was doing.