The "It's Always Sunny in Philadelphia" season 18 trailer is as outrageous as you'd expect it to be. The "It's Always Sunny in Philadelphia" season 18 trailer is as outrageous as you'd expect it to be. The "It's Always Sunny in Philadelphia" season 18 trailer is as outrageous as you'd expect it to be. The "It's Always Sunny in Philadelphia" season 18 trailer is as outrageous as you'd expect it to be. The first two episodes of "It's Always Sunny in Philadelphia" season 18 premiere August 17 on FXX, FX and Hulu.