'''Airdate:''' June 19, 2005
After "winning" at Trivial Pursuit during game night with the neighbors, Peter deludes himself into thinking he's a genius and Brian challenges him to take the [=MacArthur=] Genius Grant test to make it official. When the results come back, however, Peter is found to be mentally retarded and, after grousing over it, decides to take advantage of it, as people are more forgiving of those with mental retardation. As always, Peter takes it too far and ends up injuring his wife and getting the kids taken from him by Child Welfare.
!!"Petarded" contains examples of ([[YMMV/FamilyGuyS4E6Petarded YMMV goes here]]):
* AcquiredSituationalNarcissism: Peter develops a pretentious attitude after he wins a game of Trivial Pursuit (that Lois rigged with questions from the preschool edition).
* BaitAndSwitch: In a CutawayGag, when a man in 1945 Hiroshima who got a parking ticket and mud splashed on his asks how his day can get any worse, he sees something falling above him and says "Oh...my...God". [[spoiler: He gets attacked by a monkey.]]
* BrickJoke: A CutawayGag shows a National Geographic documentary about firetrucks. At the very end, Peter gets attacked by a firetruck.
* DepartmentOfChildDisservices: Inverted, since Peter has given social services every reason to think he is horrible father and place them with the more level headed Cleveland in the meantime.
* DisabilityAsAnExcuseForJerkassery: Peter takes advantage of his mental condition to do anything he wants, like going into the womens' bathroom and announcing "Testicles!" over a restaurant loudspeaker. It comes back to bite him in the ass later when Lois is put in the hospital for grease burns and the kids are taken away to live with Cleveland.
* EvilCannotComprehendGood: Even when trying to do good and prove he is a good father to social services, Peter interprets this as making Cleveland looking like a bad father and framing him for prostitution.
* JerkJustifications: Peter uses ''every and any'' excuse to act like a complete prick to those around him. When he wins a rigged Trivial Pursuit he becomes conceited and talks down to everyone, when he discovers he is retarded he exploits his condition to get away with any trouble he causes. When it finally bites him back and he has to prove his entitlement to his kids, he decides to do so by framing Cleveland (their current guardian) for mistreatment.
* KarmaHoudini: Played with, as Peter doesn't get any retribution for his antics because he's legally retarded.
* MyGodWhatHaveIDone: Peter after Lois' ends up in the hospital because of his shenanigans.
* NeverMyFault: Peter complains in court about "getting the bum rap" just for being retarded, disregarding even outside his stupidity, he had used his condition to act like a irresponsible jerk to his friends and family.
-->'''Brian:''' ''YEEEEAH, IN YOUR FUCKING FACE, FUCKWAD!!!''
** The number of prostitutes are counted in a manner similar to ''SesameStreet''.
** To cope with his retardation, Peter gets [[RainMan Verne]] to be his social worker.
** Stewie says Meg clears her sinuses like [[Theatre/TheOddCouple Felix Unger]].
* TakeThat: On Peter's intelligence chart "Retarded" is below "Average" and above "Creationist"
* TooDumbToLive: Peter. Justified in that this episode reveals that, technically speaking, Peter's mentally retarded, so all those past times he did stupid things was because of mental retardation and not him being an expy of [[TheSimpsons Homer Simpson]] (though some ''FamilyGuy'' detractors will still believe this).
** The entire cast decide to play Paintball with real police guns. Only Lois briefly questions the idea.
-->'''Peter:''' Alright, alright. Nobody fire at Lois, she's scared.
* YouMonster: The Judge says this to Peter, unfazed by his RousingSpeech.