Dennis, Dee, Charlie, and Frank attempt to honor Wade Boggs by breaking his record of drinking "50 to 70" cans of beer when they take a cross-country flight to Los Angeles, with Mac tallying number of beers drank because he lost the "chugging contest" to decide who qualifies for the game. Dennis and Frank try to beat each other to the mile-high club, Charlie and Dee hallucinate from excessive alcohol consumption, Mac smuggles an entire suitcase of beer onboard, and Frank gives a frat boy a possi
The Gang hosts group dating in the bar: Dennis is obsessed with a website that allows women to rate their dates with men, even trying to use The Waitress as an ally in his quest for better reviews; Frank tries to coach Mac and Charlie on how to suppress their gross, crazy, or Anti-Semitic thoughts to be more effective daters; Dee sleeps with many men to give them bad ratings.
"Psycho Pete" from high school, who was accused of killing and eating his family, returns from the mental institution and Mac and Charlie try to make him "fun psycho" again as he now appears to be calm and soft-spoken; Dennis, Dee, and Frank try to get rid of him with help from Rickety Cricket.
Charlie is eager to ready Paddy's for the annual health inspection, but the Gang's scam involving airline miles, steaks, and chickens, plus a series of other obstacles, give him a dizzy day of problem-solving.
The Gang takes measures to assuage their paranoia when a cannery owned by China opens in the neighborhood; Dennis and Mac become focused on a fetish.
The Gang members go in separate directions in their frustration from missing out on a boat ride: Dennis starts trying to control his anger and attempt to sell his Range Rover; Dee and Charlie get closer as friends and team up for "def poetry"; Frank tries to join a "new gang" who just opened a new bar; and Mac decides to date hotter women.
Mac's nasty dad Luther is in jail on a murder charge and Mac and Charlie seek to prove his innocence with disastrous consequences; Bill Ponderosa comes to Paddy's and announces his plan to drink himself to death, so Frank, Dennis, and Dee seek to either stop him or profit from him doing it.
The Gang appears as contestants on Family Fight, a fictional game show: Frank wants to spout right-wing political positions; Mac keeps mixing up which game show he's on; Dee aims for lowbrow humor; Dennis demands classiness but gets unnerved by the "wrong-answer" buzzer; Charlie's odd knack for getting fringe answers correct has a rational explanation; and the host (Keegan-Michael Key) comes to absolutely hate them all.
Frank decides to retire from Paddy's, leading the rest of the gang into a fight to determine the next legal owner.
Mac and Charlie join a fitness club that may or may not be a cult, and when Dee and Frank find out that Dennis came up with it so he can lower Mac's self-esteem and get him to stop eating his Thin Mint cookies, Dee and Frank blackmail Dennis to let them in on the plan so Frank can recruit women into the club and Dee can finally get someone to renovate Dennis and Mac’s burned apartment so they move back out.