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 [[LittleOdessa Brighton]] [[GrandTheftAutoIV Beach]].
* [[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.