Anything the players want. That’s what they do anyway, and I know from bitter experience that once I start in on listing appropriate names for cultures and races it’s just a short step to a naming language and then a full-blown death spiral into conlangs. So Umbry, Auxi-lock, Revenge, Expendable 1401, Tomato, Hermia/Horatia, Caboose, Hurlon, Poden Persas, welcome to the Land of Nonesuch! Hope you survive the experience!
Well, except for you Revenge, better luck next life.
One thing I haven’t really settled is how many languages there are and how many the characters know. Originally I was allowing each character one extra language per INT bonus, so pretty much all the characters had one or none. Everybody in the kids’ game wanted Orc, because that was the first group of humanoid monsters they ran into, and they were fun to talk to. Now I’m thinking that will be kind of dull when they run into other monsters, unless they speak common, and I’m also wondering if I’m taking too American a view of foreign languages. In a setting where you’re exposed to them regularly, it probably shouldn’t be so hard to pick them up. Maybe one extra spoken language per point of Int over 9, and one dead language per Int Bonus? It would be something to do with Int for non-Mages, given the system doesn’t really emphasize skills. And I want characters to be talking to the monsters, even the hostile ones, because that’s where the RP is.
Thoughts and suggestions? How do you handle it in your games?
Tales of the Rambling Bumblers 
I use Int checks in my Lab Lord game to try and get some sense out of spoken communications where the interlocutors don’t share a common language.
Obscure/non-humanoid languages and complex concepts are usually tested against 1/2 Int.
Really weird forms of communication require people to break out the translation magic…
@Chris – not bad, but I prefer to play out talking to NPCs instead of reducing it to a roll. I suppose I could try to interpret the roll by garbling the speech to a greater or lesser extent, but I’m not sure I can really pull that off on the fly. I’m much more likely to use that kind of test for deciphering written communications.
Don’t make me go all accent on you!
Bring it on!
I think most fantasy environments would resemble Europe a lot more, where it seems bilungualism is a lot more common. Not being European, I don’t know for a fact, but most of the English people I know also speak French, Spanish, or sometimes Gaelic, depending on where they grew up.
It’s not unfair to assume everybody knows their national tongue and the lingua franca – in my games, that tends to be Elvish (there is no Common, I dislike the idea), since I act on the assumption most languages were based on theirs.
Dead languages wouldn’t be of much interest to anyone except scholars, but I feel like monks, wizards, and clerics should probably get one for free.
And if you’re doing that, hell, give everyone a third language. Fighters would have picked one up from an area they’ve campaigned in, Paladins might have been trained in one so they can act as an emissary to churches in other nations, Rogues are exposed to the melting pots of cities and have probably picked up another language from the immigrants in the rough partsof town…it’s easy enough to justify where and how the characters might have picked on up. In fact, it might be a fun little way to flesh out a character’s history further while providing them with a useful, but not unbalancing, bonus.
There’s a lot of pidgen languages out there as well. While in our land, most of them were trade based, in an adventuring world, there’s probably at least something akin to “Don’t put pointy thing in tummy”.
Of course, since it’s an adventuring world, with magic stuff, How about a magic phrase book that you can pick up? Sure you occasionally get some wacky translations, but “Which way to the outhouse” should probably be cross-translated everywhere.
Just FYI, that name (it should be Poden – did I misspell on the sheet? [Oops, fixed that – J]) is because I had a song stuck in my head while I was making up the character. Cantiga de Santa Maria #166, as a matter of fact, which starts out “Como poden per sas culpas.”