How Did George Clooney Set the Tone on ER?

Noah Wyle says George Clooney set the tone on ER. The cast were the class clowns, and the idea that they would stay serious doctors was always going to run out, especially with Clooney in a scene. The rule was to work hard and play hard, take the work seriously without taking themselves seriously, show up, be on time, and be professional. Clooney wanted the line between cast and crew, and between foreground and background, erased so the set felt like one company.

Noah Wyle rebuilt that ethos on The Pitt: a family, hard and relevant work, and a respectful, inclusive set. He did not like Clooney's pranks. They make decent stories afterward. He is not a prank person himself.