Underworlds are ethnic. It says so right here. Furthermore, the ethnic underworld in effect is specific to the American locale of the setting.

* If the city does not have a [[FriendlyLocalChinatown Chinatown]], there are no [[TheTriadsAndTheTongs Tongs or Triads]].
* If the city is [[MiamiVice Miami]], you should learn the word "[[TheCartel cartel]]" or you will catch a bullet.
* [[Series/TheSopranos New Jersey]] and [[Film/TheGodfather New York]]? ''[[TheMafia Parla italiano o muori.]]''
** Unless it's TheRoaringTwenties, in which case [[KosherNostra Yiddish]] will come in handy (although it can't entirely replace Italian), or the 1850s-60s, when, unless you can trace your ancestry to the ''Mayflower'', it would be advisable to [[GangsOfNewYork learn Gaelic]].
** Even then, you'd be better advised to spruce up your [[TheMafiya Russian]] alongside your Yiddish before going anywhere near the vicinity of [[Film/LittleOdessa Brighton]] [[VideoGame/GrandTheftAutoIV Beach]].
** Additionally, there's parts of town where you better be down to speak that Ebonics. Harlem, certain parts of Brooklyn, and Newark especially. Spanish will come in handy in other parts of the same areas, although a lot of the time the Spanish speakers will be civilians.
* [[Film/TheUntouchables Chicago]]: You can speak Italian or [[TheIrishMob Gaelic]]. Just don't let the Yiddish guys hear you, unless you have a deal with the Italians. Don't forget to watch out for the Polish folks, as well: they own the town. And white folks: do ''not'' presume that you have NWordPrivileges anywhere in the South Side, because you ''will'' find yourself six feet under with all the other presumptuous crackers.
* [[VideoGame/GrandTheftAutoSanAndreas Los Angeles]]: Speak Spanish, and learn the difference between "barrio" and "narco". In certain parts of the city and in the surrounding countryside, [[AllBikersAreHellsAngels men on motorcycles are not your friends]]. You will also need Chinese, [[{{Yakuza}} Japanese]], and [[TheMafiya Russian]], too, and [[GangBangers Ebonics]], plus others you'd never considered (''Armenian''?). You know, really, [[WretchedHive you should just keep quiet]].
* [[TheWire Baltimore]]: Ebonics
* Philadelphia: Ebonics and Italian. Remember how "[[Music/BruceSpringsteen they blew up the Chicken Man in Philly last night]]"? That's the Mafia.
** Speaking of that song: Atlantic City, New Jersey: Ebonics in the hood, Philly Italian historically and near the casinos.
* [[Series/{{Brotherhood}} Providence]], Rhode Island: Gaelic, Italian.
* [[TheDeparted Boston]]: Mostly Gaelic, but the occasional Italian or Ebonics thrown in for flavor.
* [[Franchise/RoboCop Detroit]]: Mostly Ebonics, but you'll hear snatches of very menacing Italian and occasionally Greek. [[GranTorino If you plan on hanging in Highland Park, learn Hmong]]. The ones speaking Arabic (Chaldeans, mostly) and Armenian look menacing, but are completely aboveboard and harmless [[AsianStoreOwner unless you plan on knocking over their store/restaurant]].

The UK has the inescapable LondonGangster, as well as TheYardies to add some ethnic flavour. Russia has its own [[TheMafiya Mafiya]], Hong Kong of course has the TheTriadsAndTheTongs, and Japan has the infamous {{Yakuza}}. See GenericEthnicCrimeGang for the Honorable Mentions - gangs not pervasive enough to have their own tropes yet.