
Fantasy roleplaying games generally simplify languages, which is not really surprising, because language is complicated. Languages are complicated. If every time the players needed to talk to someone from the other side of the mountain they had to pass a dialect check and look up the results in the critical translation fumble table, it would really bog things down.
So languages are usually treated as a binary thing: you know it or you don't. Which means if you come across a sign in a cave that says "DON'T WAKE THE DRAGONS" in Draconic, if someone in the part knows Draconic then you know what the sign says. Otherwise you only know that there's a sign.
But think about real life. I don't know Latin. Do you know Latin? I don't.
But if I saw a sign that said "Caveat [something]", I might think, "that could be a warning," because I've heard the phrase "caveat emptor" and I know it's a warning. Similarly, you can only see so many signs that say "ACHTUNG!" before you put together that this is a thing that Germans often put on warning signs.
So, in A Wilder World, when you encounter writing in a language that no one in the party can read, you make a Mind Check to try to decipher it anyway, with tiered targets for general idea ("This is a warning."), subject ("This is a warning about dragons."), and meaning, ("It's warning about sleeping dragons.") The Storyteller won't give you the exact text for something you don't know the language of, "It's warning about sleeping dragons." has -some- room for ambiguity, but it's still plausible that someone who doesn't actually *know* the language could recognize or reason out enough words to get that from the sign.
I like this approach, because not only does it seem more realistic, but it gives an intellect-based adventurer a sort of task that's comparable to the nimble-fingered role of opening locks and disarming traps: "Hey, what does this say?"
A similar approach can be used with spoken language, though things are slightly different because that's two-way communication. But I'll get to that.
The other thing about languages in fantasy roleplaying games is that there usually aren't many of them, and they're more often coded by race (that is, intelligent species) than by culture or region. Elves speak elvish; dwarves speak dwarvish. Humans, ever the unmarked class in white-created, Eurocentric fantasy worlds, don't speak humanish... their language doesn't need a name, as it's the common language that everyone is expected to speak in addition to their own
This is the approach that's been codified by D&D, the grandparent of every fantasy roleplaying game on the market. 4th Edition, while keeping and even further streamlining the idea, fully acknowledges that language doesn't work this way and takes the mythic approach: each racial language is basically an echo of the way a different group of celestial/primordial beings heard the primal language of creation; "A God/Wizard Did It" applied to linguistics, basically.
I don't recall if it's acknowledged in the core books, but D&D 4E's informal assumed setting implies another explanation for the "Common" lingua franca... the backstory is that you're living among the shattered remains of a once great empire, now fallen and its constituent parts gone back to being scattered petty fiefdoms. The presence of an empire, either recent or current, does go a long way towards explaining one language being more prevalent than others across a wide area.
I'm still working on the default setting details for AWW, but the character creation rules as written are going to include three meta-languages that take the place of "Common": Local, Trade Tongue, and Imperial, with Imperial being optional depending on whether or not an empire exists in the particular game you're playing. Beginning characters choose one, with the assumed default being Local. If your character's a merchant or someone else Not From Around Here, you'd take one of the other two. A trader who speaks the Trade Tongue might have another language that's their actual native tongue, but if it's not likely to come up in the game they don't have to spend any character resources on it or record it on their sheet.
Obviously a world will have more than one languages that qualify as Local, but every game starts somewhere. The assumption will be that everyone who speaks Local can basically understand and basically be understood in the Trade Tongue and the Imperial language, because these languages will be spoken all around the place and words get borrowed and loaned among them... there's a penalty to any verbal interaction that requires a roll if you don't actually share a language, but you don't have to roll a die just to talk to someone. So, if you're in the market place you can say "Hey, how much are these apples?" without having to roll dice or act out any cumbersome translation sequence, but if you want to haggle, you're at a disadvantage.
Trade Tongue and Imperial are similarly interchangeable... it can probably be imagined that they share more vocabulary, but the penalty comes from differing syntax, emphasis, and etiquette.
The Storyteller has wide latitude to decide how far away people will still recognize the local Local. If no one in the group wants to deal with other languages to begin with, it's easy enough to decide that the same basic language is spoken everywhere you're likely to reach when walking around looking for adventures, or to set the campaign in a "local sandbox" style rather than an "open road" style.
Otherwise, places where another language is spoken can function in one of two ways. If the language is close to yours, it's like going from Local to Trade Tongue, as described above. If it's farther away, you may need to make a comprehension check to understand it and be understood. But rather than having the encumbrance of rolling every time you talk, a successful comprehension check when you're talking to someone means you've reached a level of understanding with that person and can continue to communicate basic ideas with them. Only when you're talking about something complicated or really specific is another roll needed.
(If the campaign is a wide-ranging one, player characters will probably want to pick up on Trade Tongue or Imperial as they grow in experience. If it's very wide-ranging, they might outrun the edges of the empire and the Trade Tongue that they know.)
Now, the above is still treating humans as the unmarked class. There are still also racial languages, but they work in the same fashion. If your character is a dwarf, you might speak Local Dwarvish, which allows you to speak fluently with local dwarves, and haltingly with other locals or with distant dwarves.
Obviously within the world of the game (or a world of the game, since there's no fully-fledged official game setting), the languages aren't called things like "Local Dwarvish". They have their own name. That's why I called these meta languages. The terms here are game system terms.
Another meta-variant is "Old", as in, "Old Dwarvish", which are disused antecedents of the language. Nobody speaks them anymore, but if you're poking around an ancient dwarf mine it's more useful for reading warning signs and instructions and mystical scrolls of power. Old and modern versions of the same language aid in comprehension of each other, if you only have one or the other, but are different enough to always require comprehension rolls for the one you don't have.
Picking up new languages is normally done by picking Details. Details are a minor character element, similar to Feats in D&D but also occupying the creative slot given to things like secondary skills, perks, and even extra equipment in other roleplaying games. It's not as simple as one Detail = one language. There are multiple Details that can give another language, like Polyglot (pick any two languages to read and speak, or three that you can either read or speak), Ancient Alphabets (pick any two Old languages to read, and a bonus to deciphering any text, modern or old), Imperial Citizen (Imperial language plus some social bonuses when in the empire's sphere), Trader (Trade Tongue plus knowledge of trade routes and haggling bonus), and so on.