Back in a 2012 interview done with Den of Geek, Whedon described the writing process between himself and Goddard as something of a monster kid clubhouse.
“Drew and I got a bungalow in a hotel in Santa Monica. He had the upstairs, I had the downstairs. We already had ten pages and our outline, and we’d already broken it into three acts. Then we’d wake up in the morning, we’d take an act, go through it very specifically, divvy it up, and we both had to do a minimum of 15 pages a day in order to create a screenplay. And we did not talk about anything else. You get in a writers room, and there’s just a huge amount of anecdotes and dirty jokes and off-topic stuff. Drew and I literally didn’t speak about anything except the film, and wrote all day. And I’d run upstairs and say, ‘What about this or that!’ and he’s come downstairs and say, ‘How does this connect with this?’ So it was the fastest and most enjoyable thing. We did it in three days. And obviously there’d been a lot of prep, and a lot of polish after, but basically the bulk of the thing just came from our brains.”
That sounds more like a geeky sleepover than a serious writer retreat, doesn’t it? Perhaps that excitable energy translated into the finished movie? We know Goddard and Whedon are very good at what they do so that surely helped pump out 15 pages a day. But what’s even more important is they knew their horror lore so thoroughly that they were already set up to knock this idea out of the park.
Writing is a job, just like any other creative job, but when the writers are having blast putting a story together, you get a little bit of that sense of energetic fun in the finished product. “Cabin in the Woods” is proof positive of that.