Charles Rutherford Kelly is a fictional character on the FX series It's Always Sunny in Philadelphia, portrayed by Charlie Day. Charlie is co-owner at Paddy's (although he later sells his shares) and a childhood friend of Mac and Dennis. He is also Frank's roommate and possible biological child ("Dennis and Dee Get a New Dad"). He is addicted to various harmful substances (such as glue and alcohol), and is called illiterate by his peers ("The Gang Gives Back"). He also expresses deep interest in the law ("The Gang Exploits the Mortgage Crisis"), and shows proficiency at "bird law", beating out The Lawyer in a trial. ("McPoyle vs. Ponderosa: The Trial of the Century").