SIGN LANGUAGES IN THEDAS
@zombiefishgirl and I started talking and now I'm making it into a separate post, because I have Ideas.
Generally speaking, I don't think every place has a sign language or even knows such a thing exists. But there are places which have their own sign language or which use one that originated in another country/culture.
Now, which places I think have some kind of sign language, in no particular order.
Antiva
Antivans most definitely have their own sign language, which can be learned if you know where to find a teacher. And, to nobody's surprise really, it has origins among the Crows.
More specifically, the Antivan Sign Language (ASL) is derived from Crow handsigns, which are used when stealth is paramount. After all, you can't endanger the mission just to gossip with your fellow assassin (or to pass orders). Nope, that's what the handsigns are for.
Each house has their own specific signs, kept secret from the outsiders, but as they started to co-operate more and the amount of collaboration on missions increased, a shared vocabulary was developed. And it was that shared language that has found its way first to the civilians living around and among the Crows, and from them to the general population of Antiva.
Nowadays, there are tutors who can teach you the ASL, either in a classroom setting or offering individual lessons. And it is not uncommon for people working in professions where their workplace is full of noise - and the loss of hearing is an unfortunate inevitability - to know quite a few phrases and words, and know how to finger spell many more.
Nevarra
Similarly to Antiva, the Nevarran Sign Language (NSL) originated in a secretive organisation before becoming knows among the general populous. Unlike Antiva, the organisation in question is much more benign, being dedicated to the preservation of the dead and, through them, the history and culture of Nevarra.
The mortalitasi.
Them and their elite order of the Mourn Watch is where the NSL has its beginnings.
The fact is that despite their many and varied techniques and methods of preserving the dead, the progress of decay is inevitable. Sooner or later, each and every body will be reduced to bones and then to dust. And one of the first things to go are the vocal cords, without which it is not possible for a soul to speak when recalled to its body.
(Spirits, being entities without physical bodies in the first place, are not so limited, though the exact methods they use have not been replicated to anyone's knowledge.)
In response to this loss of faculties, the caretakers of the Necropolis have worked tirelessly to create means by which the dead could still communicate with the living. After trying and discarding several methods, they have finally settled on a language of handsigns, which has since then significantly expanded in both vocabulary and users.
First finding its way to those Watchers injured in the course of duty, who were no longer able to vocalise and to their families and friends outside of the Necropolis. From there, the NSL made its way to universities, circles and private tutors of the rich, who taught the language to anyone who expressed interest in learning it and could afford the lessons.
It is in fact considered a sign of good education for a noble to be able to converse easily using the Nevarran Sign Language.
Orzammar
Another place which has extensively developed its own sign language is the dwarven kingdom of Orzammar.
Similarly to the Nevarran example, it was first developed with a thought for those who were no longer able to communicate conventionally. That is, for the needs of the smithing caste, many of whom would experience the loss of hearing due to long hours spent in the forges.
Due to this, the Orzammar Sign Language (OSL) is an incredibly precise and technical language in terms of vocabulary - there is a separate pronoun for every caste so that there's no place for ambiguity and, at the last count, there were thirty-seven words for iron ore - each one used for ores of different purity and origins.
Despite this complexity, the OSL is widely known and taught among the smithing and mining castes, among the Shaperate and the Legion of the Dead. It is also more or less known to the members of other castes and even for the casteless it's not impossible to learn this language. (In fact, many casteless women planning to go noble-hunting will go out of their way to learn it to increase their chances.)
In light of this, nobody can surprised to learn that the creator of this language has been declared a Paragon.
Ferelden
Ferelden does not have its own separate sign language. It does, however, have extensive ties of trade and blood with Orzammar due to their respective locations.
It is not uncommon for casteless dwarves to look for better prospects on the surface, be it by finding a craft in one of the many villages and towns, or by becoming merchants and facilitating the trade of goods between the two kingdoms. There has also been cases of exiled families of other castes finding their way to the surface and settling down in proximity to the entrance to their old home.
As such, it should not come as a surprise that the OSL has become somewhat known among the Fereldans, though nowhere to the point it is in Orzammar. No, the knowledge seems to be mostly limited to the people in villages in the vicinity of the entrance to the thaig, various dwarven families and the merchant and noble houses who conduct regular business with the dwarven kingdom.
Dalish
The Dalish elves do have their own signs used for non-verbal communication, although calling it a language is perhaps too generous.
In truth, it has much more in common with the Crow handsigns, being a collection of short and simplistic gestures used to communicate silently when any kind of noise would be a prelude to lethal danger. Whether it is a hunt for a particularly vicious beast or a group of humans too close to a camp, those signs allow the hunters and warriors to coordinate with each other their next course of action.
While there is an attempt at maintaining the uniformity of gestures and meanings, with each Arlathvhen allowing for comparisons and modifications, the truth is that each Dalish clan has its own vocabulary of signs. As such, it is not uncommon for hunters from two different clans to be completely unintelligible to each other.
