***This makes it sound like you think the only thing the playwright writes is the words the actors speak. The schtick is very much part of "the material" of Gary.****
That depends on what schtick is being referred to. Obviously, a lot of the actual comic business with the dead bodies, the penises, etc. is written into the script, but I assumed the poster was talking about the comic business that the actors themselves bring to the performance, such as dialogue inflection, facial expressions, double takes, etc. I agree that most of the laughs in GARY were due to the fact that the cast is so adept at that sort of stuff, rather than to the actual lines and stage business written into the play.