I've been thinking about whether or not to use alignment languages in my upcoming B/X mini mega-dungeon campaign. I mean, let's face it, they aren't listed as an optional rule, but they are among the first things dropped or forgotten.
Without doing any actual research, other than reading other blogs, it seems the alignments arise from the assumption that the game world is one that is embroiled in a struggle between the forces of Law and Chaos. All are soldiers in this great war, with the Neutral folks either being wishy-washy, fence sitters or universal harmony types.
Alignment languages, therefore, allow those on the same side to communicate despite language barriers that arise from differences in geography, species or even plane of existence.
This is rather important when coordinating a war effort on such a grand scale.
If you're playing a fantasy war game with a little bit of role-playing, it's a nice way to justify how you can have a crazy mix of races in a single coordinated army. If you drop the war game aspect, but maintain the existence of this conflict as an important aspect of the world player characters operate in, then it is still important for the same reason.
But what if your focus is the rags-to-riches by-the-blood-on-your-sword story of individuals? There's no universal conflict in which the PCs are actors. There is no epic struggle of Law vs. Chaos, just survival in the face of an uncaring universe.
This raises the question, why have alignments at all?
Perhaps they are residue of a previous conflict? Or maybe, more likely, as someone somewhere suggested, they are an out-of-game mechanism for a character's in-game conscience (personally, I love that justification of the alignments).
However, I suspect that most GMs don't drop alignments, only the languages.
But, the alignment languages can still be useful for the very same reason they're useful in a grand war of ideology: they remove linguistic barriers. A party of humans with average intelligence scores who know no other additional languages but have a member of each alignment can communicate with just about any intelligent (as defined in a humanocentric way) creature they meet!
Unfortunately, the details of the languages seem absurd. In particular, if you change alignments, you immediately forget the old language and know the new one. The only justification I can come up with for this is a divine intervention of some kind. And that works if your world is a battleground for the forces of Law and Chaos, because the gods probably care one way or another.
But I'm pretty sure the gods in my game world don't give a rats butt, because the conflict ISN'T a great war, but a personal struggle. They exist, they occasionally reward their followers, but mostly they're concerned with their own goals and interests.
So, i'm torn:
I can reject the languages wholesale, which I think takes away an opportunity for players (even if it's one they might not miss) or I can try to come up with a better mechanism to handle the effect an alignment change has on the language, because you know if I don't, it'll surely come up.