* AccidentalAesop: Any parent who has seen the episode "Happy" probably watches over their kids '''''very''''' closely whenever they play in the street.
* AssPull: [[spoiler: The revelation that Janet and Jimmy had an affair years ago could easily qualify. I mean, really, this wasn't mentioned after ''FIVE YEARS''?!?!?!]]
* SugarWiki/AwesomeMusic: The theme song, "[[https://www.youtube.com/watch?v=8w-H1umho1Q C'mon C'mon]]" by The Von Bondies, which is a kick-ass song on its own as well.
* BadassDecay -- Tommy Gavin, Season 4.
** Gets better in season five.
* BigLippedAlligatorMoment -- Season 5, episode 12. [[spoiler: Sean's ]]musical number: "How Lovely To Be A Vegetable".
* BrokenBase: Purposefully invoked by having star character Franco Rivera "come out" as a a [[http://firefightersfor911truth.org/ Firefighter For 9/11 Truth]] who points out how various policy-makers spoke of a "new Pearl Harbor" as the first step toward an American-dominated world. These views are shared by his actor, Daniel Sunjata.
* CreatorsPet: Sheila for some.
** Jerry Reilly also counts as a CreatorsPet, especially when you consider that most of seasons one and two focused upon him. It was only when they begun phasing him out (season three) that a slew of characters (most notably Garrity and Lou) began to finally get screentime and character development.
* CrossesTheLineTwice:
** ''God'', where to begin? Well, [[spoiler: Tommy raping his "ex-wife"]], then calmly talking about dividing the furniture, the frequent sexual scenes of the firefighters, and the very graphic alcohol abuse that takes place.
** How about when Lou cuts a cockring off Franco with power tools?
** Let's be honest, every episode has at least one such moment. Many have more.
* DiagnosedByTheAudience: Given his somewhat manipulative personality and his predisposition for dishonesty (and alcoholism), Tommy may very well suffer from an unspecified UsefulNotes/{{personality disorder|s}}. Less ambiguous is that he obviously suffers from a degree of posttraumatic stress disorder.

* SugarWiki/HeReallyCanAct: Adam Ferrara, a stand-up comic who was part of Creator/DenisLeary's entourage, as Needles.
* IronWoobie - Tommy has the worst 10 year span in the history of any fiction set in the real world. Let's do a note with a list of all the crap that happens to Tommy in the 10-year window we get see of his life. '''''WARNING!!! HEAVY SPOILERS IN NOTE:''''' [[note]] 2001; He was one of the many Firefighters that responded to [[UsefulNotes/TheWarOnTerror the September 11th, 2001 attacks on the World Trade Center.]] Tower One ''collapsed'' on top of him. He knew at least 50 different men who died that day. 4 of the good friends from his crew, one of which was his best friend and cousin, 2004; Because of 9/11 he shuts down emotionally, which causes his wife, Janet, to separate from him and seek divorce, 2005; He loses another friend from his firefighting crew AND a couple months later his mother, then Janet moves their three children over a thousand miles away without his permission, without leaving any method of contact, 2006; His only son, Connor, is killed by a drunk driver, then his uncle, Teddy, goes to prison for killing the driver responsible, after they were informed he was likely to walk on the charges [[ScrewTheRulesIHaveConnections due to having powerful friends.]] Plus his ex-wife blames him unjustly for their son's death, 2007; Janet hates him, blaming him for their son's death, [[GuiltComplex and he believes her.]] He asks his brother, Johnny, to act as a go-between between he and Janet to maybe repair their marriage. Johnny and Janet start having a secret affair they keep from Tommy. When Tommy discovers the affair he beats the crap out of Johnny, slams Janet violently onto the hood of a car and stops speaking to either one of them. Then Johnny is shot to death for $8,000 to stop him from testifying, this happens minutes after Johnny calls Tommy and leaves a tearful messaged on Tommy's answering machine apologizing for the affair and betraying Tommy, a message Tommy does not receive until several hours after Johnny's death, 2008; His friend/former-chief commits suicide after being forced into a desk job. His father dies sitting next to him at a baseball game, 2009; His Uncle Teddy's wife dies and in his grief Teddy shoot Tommy and leaves him to die, 2010; His godson, his cousin's only son, is left brain damaged and confined to a wheelchair after being injured in a fire, 2011;His best friend Lou is killed in a fire, Tommy is the one that finds him, and he finds him with Lou's face burned into a unrecognizable greasy, gray skull. [[/note]] and he still muscles through his life, the same way, every day.
* LikeYouWouldReallyDoIt: [[spoiler: Tommy,]] both in season 3 and 5's finales. Also [[spoiler:most the cast at the beginning of the final episode.]]
* MoralEventHorizon: This is a show about some seriously flawed individuals, so there are several which might qualify. But the biggest two come in season three, when Tommy rapes his wife Janet during a private meeting to discuss their divorce and several episodes later, Sheila (unaware that Tommy had raped his wife, but pissed off that Tommy had been seen in public with his brother's ex-wife) began a campaign of raping Tommy via date rape drugs and covering her tracks by way of making him think that he fell OffTheWagon and blacked out after wrecking the apartment. Things culminated in her drugging him and raping him and ultimately accidentally burning her house down and nearly getting both of them killed.
** Besides the rape, she also faked being pregnant, tried to force Tommy into selling his and Janet's newborn son to her, and openly opined to Tommy that she would have killed him if he had not made a speedy recovery after being shot by his uncle.
*** Mike crossed several of them early in the series. In season two, when his slightly overweight girlfriend dumps him (largely because she was offended when he began encouraging her to be bulimic), he goes all crazy stalker on her, brandishing a gun and telling her that she will never ever find a guy as good as Mike due to her being "fat". Similarly, in season three Mikey exploits a gay man he had a crush on for free oral sex and and a place to stay, while outright refuses to provide his boyfriend similar sexual favors. When called out on his selfishness and being a user, the two beat the crap out of each other.
* SeasonalRot: The second half of season five (which ran for 22 uninterrupted episodes) is disliked for fans, due to them introducing a new female fire fighter for Tommy to lust after on top of Sheila and Janet, as well as the pandering to Mike Lombardi as far as writing his IRL band into the show for a crappy arc.
* TheWoobie -- There are times when Sheila gets so caught up in all the drama and she just doesn't have the maturity to deal with it all...it's honestly very sad. Not that she's the only one. When Lou lost everything to the prostitute, when Franco lost his daughter, when Tommy loses ANYONE, watching Jerry deal with his wife, when Sean learns the truth of his sickness, etc. It's just a big Woobie show.
** Garrity gets extra woobieness given the fact that the show has repeatedly shown that he's a truly nice (if dumb) guy who behaves like an asshole simply due to peer pressure, from his asshole siblings, cousins, and coworkers. The only other character who doesn't seem to have the same inherent asshole nature to him is Lou and even he succumbs to it in season three after being bilked of all of his money by a con artist.
** Sheila's woobiness is further solidified at the end of season six and through season seven by her destructive antics being toned down and [[spoiler:her son Damion having his accident on the job, leaving her as his sole caretaker while she can't accept that he probably won't recover.]]
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