Languages in RPGs have a lot of potential, but they often get relegated to the realm of soulless mechanics, or even hand waved completely. Looking at novels, we see that languages are used as inspiration, flavor, and to instill a sense of wonder.
Languages are mysterious:
If no one in the group knows a language, that language and what it holds is a mystery. This is especially true if it’s resistant to magic or skill based attempts to make it understandable. You probably shouldn’t  place necessary clues in a magic and skill resistant language, but the very presence of such a thing makes for excellent window dressing and can form the base of a stimulating puzzle.
Languages are magical:
Languages in RPGs don’t have to be just different ways of talking. What about a language that’s actually a viral alien species in your sci-fi game or a language only able to be read by the criminally insane for your horror game?
Languages make your world more vivid:
Languages, even languages that don’t form a barrier to your group’s communication are excellent ways to add flavor and backdrop to your world. Picking a small list of adjectives that describe a language and using them to describe the “musical elven tongue” or the “brutal orcish pidgin” when they come up is an excellent way to make them easier to imagine, without much effort.
Languages identify culture:
In the real world, languages are more exclusive than inclusive. Even if you speak a second language, your accent belies your status as an outsider. This makes guarding language and using your native tongue a matter of pride, not an inconvenience to be tossed aside the instant you write “common” on your character sheet.
I agree. Too often do languages get pushed to the backseat. In a homebrewed Iron Heroes campaign, I created a language that was composed of eye blinking and facial expressions centered around the eyes. It was for a nomadic community which often had their faces covered up, and it was a way for them to communicate with one another without dealing with muffled voices.
When the PC’s encountered these people, and were exposed to the language, they spent time to learn it themselves. They they took the language and used it as a way to communicate to one another in public (in lands where the language was not known).
It is the only time that language ever played a real role in my game, other than, “Do any of you know Draconic?”
Suggested SF read: Babel-17 by Samuel R. Delaney.
Language as a terror weapon.
Twilight: 2000’s default setup was the best use of language in an RPG that I’ve ever seen: The PCs are a mixed group of soldiers from different militaries thrown together as things really begin to fall apart. Language barriers make the first few sessions really tense, and can then be downplayed as communication becomes smoother — but those first sessions are great in part because of language.
I’m developing a setting and adventure arc for Pathfinder called Kaidan: a Japanese Ghost Story setting. What makes the adventure special regarding language is that the PCs are mercenary escorts for a merchant bringing a ‘gift’ to a noble lord. However the PCs are ‘gaijin’ outsiders (round eyes), not locals.
Like old Japan, Kaidanese (peoples of Kaidan) are xenophobic of outsiders. Probably only 10% of the population or less speak the Common tongue, and often ‘broken common’. Locals speak ‘Kaidanese common’. Also the various non-human races: kappa, tengu, henge, among others each have their own language.
Then there are the ‘outsiders’ of the setting, outsider as in extra-planar often speak dialects of their comparative western outsider languages. For example Oni (demon races) speak Abyssal (Jigoku dialect) – Jigoku refers to the Japanese name for Hell.
The cosmology of the setting differs from normal D&D cosmology in that its a closed system and there are cosmic barriers between the castes even though they all live in the prime material of Kaidan. Outside of the mentioned Jikogu, there is Yomi, the land of the dead, which is an alternative Ethereal plane that only links to Kaidan. Yomi inhabitants speak the language of Yomi, or the language of the dead and ghosts.
There are many subcultures, for example Shinobi maintain there own secret language separate from Kaidan common to aid in security in messages sent between clans and clan members. The yakuza have a similar if more limited secret language of their own.
It should be fun and challenging for the PCs of the intro arc, where most cannot understand them, so reliance on translators become important. Of course the PCs can learn the language, but as stated the peoples are xenophobic, so finding some one willing to teach Kaidan common could become a problem.
Language has always been important in the fantasy RPGs I run, and the “common” tongue is not so common (mainly known by traders and travelers as a trade tongue). Whenever the PCs come across writing – whether a scroll or carvings in stone – the first thing I do is ask what languages everyone reads. If no one knows the language, I don’t give them the information until they somehow translate it, usually through magic or Linguistics checks.
Language is a very good feature for any game and setting. Great blog post about!
Following on from what hunter1828 was saying, it also makes a great side quest or build-up situation in that you might need to find someone who can translate something. If you do, can you trust that person to give you an accurate accounting? Or what if you need a mentor or instructor, but they only speak one language? Better learn that language, or you might be turned away. (Ref. the Bride’s initial experience with Pai Mei in Kill Bill Vol 2.)
Languages just generally enrich games, so long as it’s not an issue of the GM calling for constant rolls for simple, non-meaty things.
After years of tinkering with languages in my own campaigns, a friend of mine and I came to the conclusion that there are only ever two languages in an RPG: the one the PCs know, and the one they don’t.
It is difficult to convey the subtlety, nuance, and richness of different languages in a game that relies primarily on verbal communication between players. While it is occasionally amusing to have PCs or NPCs speak in some variety of pidgin and/or pantomime to represent communication difficulties, I find too much of that gets real old real fast.
So I’ve come to use language primarily as window dressing. When you get down to it, the translator/Rosetta stone/lessons are really just another kind of “item” in your typical “fetch an item”-style quest, which isn’t necessarily a bad thing if played with a bit of flavor and style.
@Shaun Welch – I’m reluctantly coming to that point of view. I want languages to be exotic, mysterious, and intriguing. But in a game largely expressed by spoken communication, it’s damned difficult.
However, I’m also finding that cultural differences are a language of their own. Lizardmen expose their throat as a sign of friendship or subservience. Elves do not reveal their full names to just anyone. Etc…
@Kurt “Telas” Schneider – Yeah, it took me a few years to finally come around to my current point of view. I enjoy linguistics, speak three languages, and have an on/off relationship with conlanging, so it’s definitely something I’d love to include in a game, given my own way.
I do think little cultural idiosyncrasies like you mention not only work better within the context of a game, but are more likely to be remembered by players. And, in the end, that is ultimately more important. Languages remain my own private pursuit, but these days I am content with that.