Seinfeld influenced It's Always Sunny in Philadelphia

Rob McElhenney has described the show as what happens when you take Seinfeld's rule and refuse to soften it. The rule is no hugging, no learning: characters end an episode exactly as bad as they began, the plots are four selfish schemes colliding, and the setting is a place they have no real reason to keep returning to. Sunny keeps the structure and removes the last of the likeability, which is the whole joke.