"The peripheral roles for Blue Ruin were designed to require less of a commitment from actors because we were only asking for three to five days of their time," explains Saulnier. "For Green Room, we had people trapped in a room, so we had to ask for pretty full commitments from everybody because the whole film takes place in about 16 hours."
But this time, in addition to a slightly larger budget, Saulnier also had the assistance of casting director Avy Kaufman, a veteran of blockbusters like National Treasure, The Bourne Ultimatum, and The Sixth Sense. And, thanks to a gritty script with a killer hook -- John Carpenter-esque punks-vs.-skins siege thriller -- he had the perfect bait for actors in their 20s looking to take a risk on a small production. In addition to Yelchin as the lead, he cast Arrested Development's Alia Shawkat, Skins' Joe Cole, and English actor Callum Turner as the band members. Rounding out the cast, he secured indie favorite Imogen Poots for the important role of Amber, the band's only ally in increasingly hostile territory.