Thieves Cant - Cant what?

The way the Thieves' Cant is written, it makes it sound like the concept is universal and exclusive to thieves, so despite the vast differences in culture, language, and race. Put another way, a human thief can communicate with a random other thief on the other side of the world, a drow thief in the Underdark or a mermaid thief at the bottom of the ocean, while at the same time can't actually teach this doublespeak to a wizard with max intelligence.

My friends think this is kind of insane, and only makes sense if the god of Thieves set this up.

Are we misreading this? Or should there be some sort of added limitation?

I think it would work better if it was kind of like the Artisan background, so the Thieves' Cant only works with certain Thieves' Guilds.
The way the Thieves' Cant is written, it makes it sound like the concept is universal and exclusive to thieves, so despite the vast differences in culture, language, and race. Put another way, a human thief can communicate with a random other thief on the other side of the world, a drow thief in the Underdark or a mermaid thief at the bottom of the ocean, while at the same time can't actually teach this doublespeak to a wizard with max intelligence.

My friends think this is kind of insane, and only makes sense if the god of Thieves set this up.

Are we misreading this? Or should there be some sort of added limitation?

I think it would work better if it was kind of like the Artisan background, so the Thieves' Cant only works with certain Thieves' Guilds.



its realistic in some ways, pro wrestlers speak carney when in the ring. and carney is the same no matter where you are. also its something that can easily be changed or modified by the dm.
Thieve's Cant hasn't come up much in the games I've been in.   I'd rule that it's somewhat of a slang language which is only useful when talking about things related to theivery.  So, you wouldn' be able to have a philosophical conversation in Theieve's Cant, but you could say a city guard informant just entered the tavern.

As far as speaking to fellow theives in a foreign land, I'd say no (if I were DM).  I feel TC is a variation of the Common Tongue and if the 'common' language is something else on another continent, then your version of TC would not work there.

But that's the beautiful thing about DnD:  your DM can decide how it all works in his world.  It's possible the god of thieves imbues all thieves with the ability to communicate with each other across the universe and that's fine for your campaign.
You fight for your freedom? Well, I fight for the freedom of all.
I think it should be treated as an actual language, a secret language much like Druidic.
It's a DM call, but I would safely assume that the thieves have been voyaging and thus have spread the cant even far away - but maybe not where they couldn't have possibly gone.

Now, I would say that Thieve's Cants are variations of the spoken languages, plus a small list of pretty much invariable terms which concern only the "work". If your thief character don't share any language with the ones he's trying to communicate with, I would rule an INT check to do the trick for small talk. No debate about philosophy indeed, but it's not the point of thieves cant anyway.
Go to any diner and order in diner talk and they'll know what you're talking about more likely than not. They might say it a different way in most instances, but there's they will understand another diner's lingo.

Same with this. They have the same craft, same trade. They have slang, jargon, shortcuts. Same tools. If once in a while they the local's word for lockpick is picka instead of knockers, they'll understand soon enough in context.
Thieves' cant was a real thing, so it's hardly strange and does not need any appeal to a god of thieves or anything else to explain it. To be sure, the various "cants" used in the 16th and 17th centuries varied by language group (e.g. one was used in the English-speaking world, another in southern Germany/Switzerland, etc.). However, since D&D posits that there is a "Common" language, there is no difficulty in thinking that there should be a Thieves' Cant used by the criminal classes across the Common-speaking world.

If you get rid of Common, you can also multiply Thieves' Cants, of course, but the latter is not any more strange than the former.
Theives Cant cannot be taught to someone else because someone else is not a thief.  Simple as that.  If they become a thief, then they can learn Thieves Cant.

Speaking of ... any news on multiclassing yet? 
Speaking of ... any news on multiclassing yet? 



Not much, but if you look at the bestiary for converting Against the Slave Lords (A-series), you'll notice that some of the characters there are multiclassed. It's not much to go on, but for the time being it looks like 3e-style, i.e. a hit dice for each level in each class, rather than the "blended"/average hit dice style of AD&D. Of course, I believe Mearls said some time back that multiclassing would be (more or less) as it was in 3e (i.e. gain a level, choose a level is a class, either one you already have, or a new one). Of course, the bestiary entries won't give you all the crunchy bits about levelling up.
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However, since D&D posits that there is a "Common" language, there is no difficulty in thinking that there should be a Thieves' Cant used by the criminal classes across the Common-speaking world
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Nailed it