Eugene "Gino" Luciano (Ray Liotta) is a medical student living in Pittsburgh with his mentally disabled twin Dominick, aka Nicky (Tom Hulce). Nicky pays for Gino's education by working as a garbageman. Gino receives an offer to complete his education at Stanford University, but he doesn't want to leave Nicky alone, and he doesn't think Nicky will be able to handle being uprooted and moved across the country. Their relationship is further strained by Nicky's coworker Larry (Todd Graff), who seems to enjoy stirring up drama, and by Gino's girlfriend Jennifer (Jamie Lee Curtis), who makes Nicky worry that Gino will abandon him for her.
Dominick and Eugene contains examples of:
- Accomplice by Inaction: Eugene feels a measure of guilt for always being too scared to do anything when his father would hurt him which led to Nicky always having to stand between them and take the blows for him, one of such incidents which ended up giving him brain damage.Eugene: You were brave. You were always standing up to him. I was always scared. Like the day that it [the incident] happened. He was out of his mind, and I thought he was going to kill me. And you stood in front of me to protect me. And he hit you, and hit you, and just kept hitting you... and I've hated him every day of my life for what he did to you!
- Affectionate Nickname: Dominick is called "Nicky" by almost everyone in the neighborhood, and he in turn is the only one to call Eugene by the nickname "Gino".
- And I'm the Queen of Sheba: When Larry says that Gino and Jennifer must be having sex, Nicky says, "He's just helping her study, that's all." Larry answers, "Sure, and I'm the Pope's long-lost son."
- Big Brother Instinct: Gino is Nicky's (non-identical) twin, but acts as a protective big brother because of Nicky's mental handicap.
- Bringing Running Shoes to a Car Chase: When Mikey is badly injured from being pushed down the stairs, Nicky tries to chase after the ambulance.
- Bullying the Disabled: Nicky is a frequent target. Once some boys surround him, knock his grocery bags out of his arms, and try to force him to touch their boogers until Gino chases them away.
- The Caretaker: To an extent, Eugene serves as this for Dominick, in that he has to stop his brother from being manipulated by others around him and keep an eye out for his needs, such as having to remind Dominick to eat breakfast, take Fred for a walk and making sure he gets to work on time. Not to mention his dilemma of having to leave his brother to take care of himself alone to finish his education.
- Character Tics: Nicky rubs his fingers together when he's nervous.
- Cheating with the Milkman: Larry regularly visits Mrs. Vinson (Jacqueline Knapp), a woman who lives on the garbage route, to help her with her "plumbing problems."
- Chekhov's Gun: An actual gun in this case. Early in the movie Larry uses a gun (calling it "Jesse's .22") stored in the garbage truck to get rid of rats that scavenge the garbage dump, even mentioning how Nicky is too afraid to use a gun when the latter remarks on that. Later on, after seeing Martin kill Mikey, Nicky runs to the truck, retrieves the gun and threatens the Chernak family with it when kidnapping Joey, thinking he is protecting the boy.
- Childhood Brain Damage: Nicky "fell down" and hit his head when he was a kid. He remembers nothing from before the accident.
- Cut Himself Shaving: Mikey Chernak (Tommy Snelsire), a boy Nicky's befriended who lives on the garbage route, is being beaten by his father Martin (David Strathairn). He tells Nicky the bruises are from falling over.
- Death by Newbery Medal: Fred the dog is hit by a car and killed during a picnic.
- Didn't Think This Through: Though he had good intentions, Nicky really didn't consider the consequences of kidnapping Joey from his family at gunpoint and then going on the run and hiding out. Of course the cops would get involved and treat this as a serious kidnapping case, especially due to the presence of the gun and not knowing his motive for doing so. Justified to an extent as he is slow and likely didn't consider it, as well as being in a state of panic due to what he saw and remembered directly before the kidnapping. Still, it's a miracle he didn't suffer any consequences or punishment for that, which viewers found to be the only unrealistic element in the film.
- Disappeared Dad: The brothers' dad "went away" after Nicky's accident. This is because it wasn't really an accident at all, but was caused by their father violently beating him.
- Ethical Slut: Mrs. Vinson, the woman that Larry (and according to him, many other men) have casual sex with. While extremely sexually promiscuous, she's shown to be a kind and caring person in her interactions with Nicky and with her neighbors after Mikey's death.
- Fingertip Drug Analysis: Guido (Joe Maruzzo), a guy from the junkyard, pays Nicky ten dollars to deliver a newspaper that has drugs hidden inside it. When Gino finds out, he opens the packet hidden in the newspaper and tastes the powder.
- Future Me Scares Me: Downplayed. Eugene admits during his rooftop conversation with Dominick that he's afraid of himself when he gets angry, especially when that leads to him hurting Nicky, because he fears that he'll become just like their father, someone who was always taking out his anger and temper on them through violent beatings.
- Hate Sink: Martin Chernak (Mikey's father) is an all-around low-life who abuses his son and eventually kills him, then lies and threatens Nicky to cover up what he did. When Nicky kidnaps Martin's younger child to protect him, Martin tries to shoot him.
- Jerk with a Heart of Gold: Larry is quite sleazy and likes to pick on Nicky because he's such an easy target, but underneath it all, Larry likes and looks out for Nicky.
- The Kindnapper: After Mikey's death, Nicky worries that the same fate will befall his baby brother Joey. He runs into the Chernak house, grabs Joey, threatens the family with a gun, and holes up in an abandoned warehouse. A SWAT team is sent after him, and Gino has to talk him down.
- Lying to Protect Your Feelings: Eugene is revealed to have been doing this for Dominick by telling him that his disability was caused by a childhood fall - in reality, it was due to their father beating him. When Nicky finds out the real reason and demands to know why Eugene lied and hid the truth from him, Gino admits that he didn’t want his brother to live with the knowledge of that weighing on him if he didn’t have to.
- Mood Whiplash: The day after the big fight between the brothers, they along with Jennifer, their neighbor Mrs. Gianelli and their dog Fred go on a picnic. Dominick and Eugene have a conversation where Eugene tries to explain how he's stressed over having to leave his brother to complete his education, when suddenly their dog Fred is hit by a car. The next scene shows Nicky crying in church, making it clear Fred died.
- Also Mikey’s death. Dominick is out on his garbage run a few days after Fred’s death, just a normal everyday run. While collecting the trash from the Chernak house, he witnesses an argument between Martin and Mikey that ends with Martin pushing Mikey down the stairs and then calling an ambulance. Dominick goes to the hospital afterwards to find out Mikey died from damage sustained to his head when he fell.
- Nervous Tics: Nicky tends to rub his fingers together when he's feeling nervous.
- The Reveal: Nicky wasn't brain damaged in an accident. His father was violently beating him.
- Rewatch Bonus: When rewatching the movie a second time with knowledge of The Reveal, a few subtle hints can be noticed before the brothers' confrontation in the warehouse indicating that there’s more to Nicky’s Childhood Brain Damage than just "falling down":
- It’s been mentioned how Eugene is smart and has a great memory, yet whenever Nicky asks him to tell the story of what happened to him as a child, Gino simply says something along the lines of "You fell, hit your head, and became slower because of that.", not seeming to know any more than that. And he repeats the same story verbatim, never elaborating or explaining in any more detail. Because that story is completely made up and not what actually happened - Eugene doesn’t elaborate so that Nicky doesn’t realize something’s up or accidentally trigger his memory (which ends up occurring later on from something else).
- When Dominick mentions how their father had to leave after his accident, Eugene looks away and doesn’t say anything until Nicky starts talking about something else, and then Gino tells him to go to bed. He knows what their father was really like and why he actually left. Unlike Gino, Nicky doesn’t remember due to his handicap.
- Later before going to sleep Nicky mentions how he’s glad Eugene’s not mad at him. Eugene has a pensive, almost worried look on his face afterwards. Because he worries about becoming like their father, who was angry and took it out on them as children.
- Eugene looking genuinely horrified after his argument with Dominick where he shoved him into the wall and hurt him, needing to walk away and breathe afterwards, even though he had never had such a serious reaction whenever they argued before. That’s because despite having argued and lost his patience with his brother before, Gino had never physically attacked him, which was later revealed to be his worst fear - hurting his brother and becoming abusive and violent like their father, whose beatings of Nicky had been what gave him brain damage and changed their lives forever.
- Staircase Tumble: Martin tries to lock Mikey in the cellar as a punishment. When Mikey resists because he's scared, Martin shoves him through the door so that he falls down the stairs. He hits his head and dies at the hospital a few hours later. Nicky witnesses the assault, which causes him to realize the truth about his own injury.
- Thousand-Yard Stare: After Nicky witnesses Martin throw Mikey down the stairs, he can do nothing but stare forward aimlessly and cry from the shock of what he saw, becoming temporarily unresponsive to anyone speaking to him. And later it's revealed that he wasn't just crying due to what he saw, but also because of his...
- Trauma-Induced Amnesia: Nicky has brain damage and a learning disability from when he fell down and hit his head as a child, which also made him lose all his memories before the accident. Or so he thinks. Overlaps with Repressed Memories: seeing Martin abuse and kill his son triggers Nicky's memories and makes him remember it was actually his own father's abuse that gave him brain damage due to the similarity between the two incidents.
- Wham Line: When Eugene chases after Dominick who's kidnapped Joey in a misguided attempt at protecting him, Dominick explains how he's protecting Joey from being hurt by his father... just like he'd been. He then reveals he realized the true reason behind his brain damage, which Gino had known and hidden from him all along. The look on Eugene's face when Nicky says this only further confirms it.Dominick: You've been lying to me, Eugene. I never fell in no accident. Our dad hurt me. Ain't that right?
- You Didn't See That: A non-comedic version. Nicky goes to the hospital after Mikey’s "accident" to see how he’s doing. Martin, Mikey’s father, who was the one who hurt Mikey (though no one other than Dominick knows that) confronts Dominick in a storage room and tells him that Mikey died, and that if Dominick tells anyone he killed him Martin will kill him too.Martin: You didn't see nothin'. You say you saw anything, and I'll kill you. I swear I will. You don't know nothing. Got it?
