Bros Before Hoes: Nino makes with Gee Money's mistress when she offers herself to him. When Gee Money later voices his anger at Nino for taking everything for himself, Nino dismisses the girl as a skank and says that Gee means infinitely more to him.
Bulletproof Human Shield: In a sickening example, Nino uses a little girl as this when the Mafia tries to assassinate him at a party.
If You're So Evil, Eat This Kitten: Nino Brown relates a tale from his youth: His gang initiation involved killing someone, but it couldn't be a rival gang member ("too easy"). He ends up shooting a schoolteacher on the street in broad daylight. Unfortunately for Nino, the person he relates this tale to is undercover cop Scotty, the schoolteacher's son.
Misaimed Fandom: In-universe, Nino is a noted fan of Scarface, watching Tony Montana's shootout at the end of the movie multiple times and quoting the "the world is yours line" as an inspirational motto. He probably quits watching before Montana gets shot, or he might have drawn parallels between the Miami drug kingpin's demise and his own possible (and eventual) downfall.
Mistreatment-Induced Betrayal: Implied to be the motivation behind Gee Money's betrayal of Nino. They were supposed to be partners but the latter treated the former more like a sidekick, taking everything for himself.
Nothing Personal: A major plot-point. When undercover cop Scotty Appleton and drug kingpin Nino Brown are hanging out one night, Nino confesses that he killed an innocent school teacher as part of an initiation into a gang. Scotty asked Nino if the killing was business or personal. Nino made it clear that all his killings are business, never personal. Turns out that school teacher was Scotty Appleton's mother and he nearly kills Nino Brown during the climax, making it clear that killing his mother was personal.
The charismatic drug lord Nino Brown gave such a speech to the old military veteran, after the veteran tries to reason with Nino that he's destroying his own community and hurting his own people selling drugs. Nino's response:
Nino Brown: Look at you... in a few years they'll be marking your grave. Me? I'll be right here. What can you offer them? Another "I have a dream" speech? Some of that same shit you ripping off to me? Look where we at. Not a pot to piss in, nor a window to throw it out of. You's the fool, old man.
Nino Brown continued to joke about the war veteran later that night. But the old man would get the last laugh.
Smug Snake: Nino's sliminess reaches its epitome near the end when he makes a deal with the prosecution for a reduced sentence. He gloats to the cop who tried to get him convicted and whose mother he killed years ago to come work for him when he's back on the streets, and praises the American justice system to the press. He is almost immediately publically killed vigilante-style by an old man whose life he destroyed earlier in the film.
Spanner in the Works: Nino Brown is able to fast talk his way out of serious prison time, only to get killed by an old war veteran he didn't take seriously during the film.
Stop or I Will Shoot!: Subverted when the hero cop chases a young criminal through an extended Chase Scene and the cop never draws his gun. However, when the crook suddenly draws a gun, that is when the cop draws his own and shoots him down.
Very Loosely Based on a True Story: Nino and the CMB are based on Boston drug lord Darryl Whiting and his crew. Nino's last second outburst in court was directly lifted from Whiting's trial. The whole Carter House premise was inspired by the Chambers Brothers of Detroit.
Vigilante Execution: Druglord Nino Brown walks arrogantly out of the courtroom in front of the police protagonists, confident he will not serve a sentence commensurate with his crimes. The old man who was hounding Brown throughout the film for destroying his neighborhood with his drug trade shoots him dead in the courthouse foyer.
Villainous Friendship: Nino has a friendship with Gee Money that doesn't seem to be faked. When they establish their criminal empire Nino tells Gee that they've finally made it and that they have to look out for each other. Near the end he expresses his friendship with Gee as more important to him than all the money and women he has gotten, but they just can't go back to the way they were after Gee betrays Nino by making a deal behind his back. Nino struggles to kill Gee as tears roll down his face.
Villain with Good Publicity: Nino tries to gain the people's support by handing out free meals to the poor and money to the children. The cops Scotty and Peretti openly call his Robin Hood act out as crap, as does an old man whose grandson is among those children. At the same time, Nino has forced entire families out of their homes to build his drug factory and is preying on the poor to sell his drugs.
You Have Failed Me: After the police infiltrate the drug operation and the CMB are forced to destroy their production plant when they capture a police informant, Nino threatens his gang with killing them if they fail him again, stabbing one through the hand to make his point.