EzekielRaiden
Follower of the Way
Wellll....not complete nonsense. It just requires a relatively constrained area of consideration and at least one of three things:The everyone understands everyone else Common is a D&D nonsense.
- An important, usually simplified, trade language which is spoken relatively widely across the region in which trade occurs. Consider Koine, which was an Eastern Mediterranean trade language for something like 650 years (from roughly 320 BC to 330 AD.) If you count things from Magna Graecia in Italy to the eastern edge of Anatolia (modern Turkey), and from Lower Egypt up to Crimea, it was widely spoken in nearly all coastal areas, and would have been at least useful even outside of that range because, y'know, trade.
- A hegemonic culture rules over a region, and thus can enforce a single language through bureaucracy and administration. Consider Latin in Western Europe and north Africa, which was the common language spoken from what we would now call England in the northwest to the Arabian Peninsula in the southeast and almost everything between the Danube and the Sahara, and this importance continued (even if it waned)
- A central religious core around which the various nations build their center. Catholicism has already been mentioned, but Islam brought Arabic and ensured that it was extremely prolific--to the point that, for example, modern Spanish is heavily influenced by Arabic, and we even have Arabic-origin words in English as a result (e.g. "algebra," from the Arabic al-Jabr, "reunion of broken parts," that is, from the Al-Kitab al-muhtasar fi hisab al-gabr wa-l-muqabala, "The Compendious Book of Calculation by Completion and Balancing," or "algorithm," derived from the name of an Arabic mathematician, Al-Khwarizmi.)
So, while the idea of having a truly universal language is certainly a bit silly, D&D settings are typically small enough and interconnected enough that a trade language, administrative language of the current/relatively-recently-fallen empire, or common-religious-root language could do the trick. Pair up any two (or even all three) and you get quite an easy explanation for things.
Unless, of course, you have a setting like the Forgotten Realms, where you're trying to articulate stuff for literally the whole world, no exceptions, in which case yes, a truly universal "common tongue" is silly. But most settings aren't bothering with THAT comprehensive of coverage--it's a lot of work, and squeezes out a lot of the places where player agency and alternative concepts could be usefully inserted.