Two comedy forces collided this week on Abbott Elementary, as the school staff welcomed the Paddy’s Pub gang from FXX’s It’s Always Sunny in Philadelphia. Did the crossover episode make the grade, though?

The star of the FX series also admits he was initially hesitant about the crossover concept as 'It's Always Sunny in Philadelphia' heads into its 17th season.

A crossover television event is always a thrilling prospect—not one, but two of your favorite shows coming together as one? There have been plenty of surprising combinations throughout the years: The Jetsons met The Flinstones,