You just go and it’s like a dream, you go to an awesome place and stay in an awesome hotel and just for a couple of hours a day you swim around in South Park ideas. The first retreat I went on just seemed to gel. It’s mostly those guys [Trey Parker and Matt Stone]. I kind of hang out in the room. It’s very chill and then in the 13th season they actually brought me in as a writer and I actually wrote on the show for part of that season — I’m doing it again this season too. In April I’m going out there for three weeks. It’s just awesome. You hang out for a couple of hours just working out these ideas, it’s very peaceful. Just a couple of people in a room with Trey and Matt. It’s like a dream come true. But it really is those guys; it’s like they are working out their idea and you are saying, “Oh, that is funny.” Or maybe it’s this or that, you know what I mean? You kind of throw out ideas, they run with it, and make it insanely funny.
Bill Hader helps write South Park, which is written in a much different fashion than the traditional sitcom. They basically shoot ideas around with a small group of friends/writers and then Trey and Matt end up writing every episode. Here’s Hader: