Translator: Sorry, no idea on that one.
Being in crime is risky business. Just going about a dishonest day's work can land in you in prison, banished, or even with your neck in a noose (or worse). And since you never know who's affiliated with the police, or who's interested in the reward you have posted on your head, it's in your best interest to keep things secret, even from those who might overhear you.
Enter the Thieves' Cant, a secret language used by such lowlifes to go about their daily "business" without being caught. The language can range from elaborate slang lexicons to entirely different languages unrelated to those spoken by the everyday folk. The Trope Namer is the Real Life Thieves' Cant (also called "Rogues' Cant" or "peddler's French"), which was used by criminals, beggars, and others on the fringe of society in Great Britain for some time; similar cants were present throughout Europe. This history is probably why such cants are prevalent in Medieval European Fantasy, though they show up elsewhere as well.
This cant is often the working language of a Thieves' Guild. If you don't know cant, you "cant" get in.
If characters are trying to infiltrate the criminal underworld, or require their assistance, expect knowledge of cant to be a prerequisite for gaining anyone's trust. A character with a criminal past will often be revealed to be fluent in cant; this can be used as a way to introduce his criminal history as well. In many games influenced by Dungeons & Dragons, the common Thief class will have a specific Thieves' Cant language usable only by that class.
Related to Spy Speak, which is simply speaking in code, as opposed to using new vocabulary and languages — though criminal Spy Speak may well evolve into Thieves' Cant should it catch on with others in the criminal world.
- The premise of Gentlemen of Fortune is that a nice-hearted kindergarten teacher has to infiltrate the criminal underworld, posing as his criminal doppelganger. He prepares for that, in particular, by studying Fenya. Other criminals he interacts with also mix a lot of Fenya words into their speech.
- In Ocean's Twelve, Danny and Rusty engage in this with their contact Matsui. A confused Linus decides to get in by quoting the lyrics to Led Zeppelin's "Kashmir". The others inform him that he just called Matsui's niece a whore, but later admit that the whole thing was just an elaborate prank.
- The Secret Drasnian Language in The Belgariad is a variation, both in that it was developed for spies (though still largely used by thieves, simply because many of them are the same people), and because it's a sign language. As Drasnians are a Fantasy Counterpart Culture of Italians (in part), they are known to gesticulate greatly while talking, so the language is designed to allow its users to have a secret conversation with their hands while simultaneously holding a more mundane one with their voices.
- In A Brother's Price all of Jerin's family are fluent in thieves' cant, due to their grandmothers having been thieves.
- Briar peppers his dialogue thief slang in Circle of Magic. He confuses the others by calling themselves kids, which they take to mean baby goat since the word isn't widespread, and persistently calls their well-dressed teacher Niko a "Bag" (i.e. moneybags, a good target for thievery).
- The Discworld Thieves Guild Diary 2002, includes a dictionary of cant. It also reminds licensed thieves that a failure to speak in cant could call their legitimacy into question, just like failing to wear a Blatant Burglar outfit.
- In Going Postal, Vetinari attempts some cant and gets it wrong, warning Moist that he could be "dancing the sisal two-step". He is discreetly informed that he meant "the hemp fandango".
- When Vimes is thrown back in time in Night Watch, he has to remember all the thieves' cant from thirty years ago. When he meets young Nobby Nobbs, he lists off a string of offenses that includes "running rumbles, snitching tinklers," and "pulling wobblers", which trips him up because the last is from the present day. Nobby quizzes him on several other phrases, like oil of angelsnote a dimbernote and fleaguing a jadenote . The whole scene is likely yet another allusion to Les Misérables, seen below.
- Fenya (Russian thieves' cant; see below) crops up every now and then in the Erast Fandorin series, such as when Xavery Grushin (a police inspector in disguise) manages to defuse a conflict with a Moscow gang in The Death of Achilles by speaking fluent Fenya, which convinces them he is a friend, though not quite.
- Present in the Gentleman Bastard book series, which also includes an intricate sign language disguised as innocuous hand movements so not only do outsiders not know what is being communicated, they don't even know communication is taking place.
- The Victorian criminal slang used by the crooks in The Great Train Robbery is so impenetrable that their trial often has to be stopped so that the upper-class courtroom lawyers and judges can spend several minutes trying to extract from them what they actually mean. The thieves are so used to speaking this way that they often don't actually know any other way of saying something, and it can take quite a while for both parties to be able to understand each other, even when they are legitimately trying to speak clearly.
- The French cant of Argot features heavily in Victor Hugo's The Hunchback of Notre Dame. A dissertation on the language can also be found in Les Misérables.
- In Steve Perry's The Machiavelli Interface former prostitute Dirisha Zuri has to translate some of this for the other Matadors (Emile Khadaji used a street kid to send a message to the group), and comments that the slang has evolved some since she was a kid.
- In the Tales of Kolmar trilogy, there is a mercenary's cant. Jaime, a former merc/assassin, is able to speak it.
- Tortall Universe: In Beka Cooper, residents of the Lower City, where the line between legal and illegal is very thin, have an extensive slang vocabulary, most of which is cobbled together from historical slang ("foist/pickpocket" and "doxy/prostitute", for example). People from the Cesspool neighborhood have their own subset of slang that is considered to be particularly disgraceful.
- In Vatta's War the pirates conquering the galaxy have their own secret language. In the last book one of the younger Vattas realizes the enemy language is quite similar to the "family code" used by one of his classmates, her father turned out to be a spy but she didn't know and actually helped translate for the coalition.
- Villains by Necessity: Arcie (thief) and Sam (assassin) have a conversation in rogues' cant so an evil sorceress won't know their plans to get the drop on her.
- In Cheers episode "Pick a Con, Any Con", the gang asks con artist Harry the Hat about George, a different con artist who ripped off Coach. Harry loses them with his thieves' cant.
Harry: Any bird-dogger knows him. He runs paper and cubes, mainly in the crib, sometimes up against the wall. Puts on a straight-up-guy front, and then grinds away slow with coolers and hop toads, real rip and tear kind of stuff.
Sam: (obviously clueless) That sounds like him.
- Averted a little bit later in the conversation, when Sam asks "What do you call the guy that brings the money?", and a nonplussed Harry responds "We call him the guy that brings the money."
- Crossing Lines: Tommy and his brother talk in Travellers' Cant while held in an interrogation room together so that watching police can't understand. London, however, knows it too.
- Horrible Histories did a sketch in which the news was read out in Tudor criminal slang. It ended in an Even the Subtitler Is Stumped situation. They later did another sketch featuring Victorian criminal slang.
Ringleader: Alright, this is a flummet job. We'll need a rook, some Davy's dust, and a fagger. Luckily I knows a nimmer who'll crack a crib for a spangle. Any questions?
Crook: ...Sorry, I'm new. Could we run through that again?
- In Dungeons & Dragons, Thieves' Cant is a language spoken by members of the Thief class that is limited to discussion of thievery-related activities (burglary, fencing loot, confidence games etc.). It can be used by someone to identify themselves as a thief to other thieves.
- The Planescape setting used actual words from Victorian-era cant as part of planewalker slang. Unfortunately, they didn't always do a good job of checking their meaning.
- In Elizabethan times, Thieves' Cant (the real one) was heavily featured in what was called "rogue literature," especially theater aimed at the lower classes. The Beggars' Bush, a play by Francis Beaumont, John Fletcher, and Philip Massinger, is almost entirely in Cant.
- EverQuest features Thieves' Cant as a language spoken only by the Rogue class.
- Final Fantasy XIV features a bit of this in Limsa Lominsa (a city-state sitting on the coast and well known for its history with pirates and thieves of all manners.) This is seen most prominently in the Rogue's Guild and the quests revolving around it.
- In World of Warcraft, Gutterspeak was originally the thieves' cant of Lordaeron before the kingdom fell to the Undead Scourge. After the undead regained their free will and founded the Undercity in the catacombs of the ruined capital Lordaeron, they designated Gutterspeak as their official language.note
- Several of the Things Mr. Welch Is No Longer Allowed to Do in an RPG involves talking the cant.
201. My thief is prohibited from speaking solely in Cant.
2229. It's Thieves Cant. Not Illegalize.
- In the Whateley Universe, different locales have different variants of Thieves' Cant. In New York City, they tend to use show-biz slang. So a producer is the guy running the show, a prop man is a guy who relies on holdouts, et cetera. This tends to give you an idea of who's an absolute newbie.
- The Simpsons: In one episode, Homer teaches Bart hobo signs (which were a real thing), such as one that advertises people willing to feed and put them up for the night... along with a house that has a mass hobo graveyard in the back.
- Aside from the Trope Namer described above, other examples exist as well, such as Rotwelsch in southern Germany and Switzerland and the atrovački in the Serbo-Croatian speaking areas of the Balkans.
- Fenya (феня) or Fenka (фенка) is the dialect of Russian used by The Mafiya. Its use is declining, but it was prevalent in the 1990's, when criminal organizations operated largely unchecked.
- Grypsera, a secret language of Polish prison inmates. It evolved in the 19th century in the areas of the Russian partition. Another secret language, kmina, was used by Polish thieves.
- During The Great Depression, traveling vagrants developed a written cant called hobo signs to alert other vagrants of certain services, conditions, and warnings. For example, they'd write a symbol on a surface or wall to indicate that a local was willing to provide a place to sleep for the night.
- Many real-life cants drew much of their vocabulary from Romani, the language of the Roma people (commonly called gypsies in North America, though this is considered offensive in (western) Europe). The Roma were ostracized for centuries in European cities and towns and were forced to live on the outskirts of society, which generally entailed making a living off of crime, hence the stereotype of "gypsy thieves." Because Roma were so prevalent on the societal fringe in Europe, cants took many words, even sometimes the bulk of them, from Romani.
- Klansmen used a specific language to speak between them. A lot of it is frankly kind of ridiculous, especially the ones that use a whole bunch of "Kl" substitutions. Of course, what isn't fundamentally absurd about a Brotherhood of Funny Hats-turned-gang of racists who dress up like Bedsheet Ghosts?
- Cockney Rhyming Slang may have started out as this.