"Do you speak Common?" "Of course I do! Everyone speaks Common..."
My group is starting a somewhat experimental campaign. We're using a setting that is neither canon (e.g. described in a book) nor entirely homebrewed: it's "what we could remember from the book that we read once" plus the world map from the book, marked up some added locations and country borders, and a short political history we developed.
My problem is that according to the book (Endival) every race speaks their own language and Common. In my opinion this has two downsides. First, it does not feel right that just anyone can communicate with people from the other side of the world. Second, this strongly diminishes the value of learning another language. It means you can go from one side of the world to the other and still fluently speak the local language (i.e., Common). Also, all humans speak Human, all dwarves speak Dwarven… but there are several warring human kingdoms and yet they all share a common language?!
I would like to make the world resemble our own history a bit more. My concerns are:
You and I speak "Common" – it's called English. But this is the result of the recent globalization made possible with the advent of the Internet. Even though the setting I am talking about is more sophisticated than the historical middle ages (due to widespread powerful magic), they are far from anything equivalent to microprocessors, space exploration, freight in the millions of tons and so on. There should not be a Common language.
On the other hand, suppose we decide that there is no Common language. Then we run into problems during character creation: A very basic and classic player freedom is to choose their character's race. Now we have a colorful group in which no one can speak with the others (why waste a skill to learn a language, when your squishy starting-level character could learn to swing an axe or cast spells better). Even if they agree to all invest skills in a shared language, once they begin travelling (i.e., adventuring) they quickly run into people with no shared language.
What are some ways to handle this? How can we have a realistic set of languages without making adventuring prohibitively difficult?