Authors:

I think the more depth you build into the characters, and the more you see where they came from, the more fun you can have. Setting up different characters in different relationships is always helpful as you move forward.

"It's Always Sunny In Philadelphia's Rob McElhenney, Glenn Howerton, and Charlie Day". Interview with Noel Murray, tv.avclub.com. September 16, 2008.
I think the more depth you build into the characters, and the more you see where they came from, the more fun you can have. Setting up different characters in different relationships is always helpful as you move