by greyarea » Fri Oct 04, 2013 2:29 pm
Alignment language actually means something specific. It is a language that would only be known by people of that alignment (and all people of that alignment). Think of it as a "gang slang" that would be used to tell neighborhood gangs apart. Alignment languages are the languages that the characters would use when praying to or communing with their deities. It can be the main language of a town where only one deity is worshiped, making it easier to identify outsiders or easier for outsiders of the same alignment to be accepted.
Alignment languages are handed down by the deities of that alignment and is given to all members of that alignment -- no one outside of it can learn it and everyone within, regardless of intelligence, can speak it.
As such, it can be very powerful and very useful.
For example, two Chaotic Good characters can have a conversation without the Neutral Good character knowing what they are talking about.
Similarly, a Lawful Evil character might use the language in asking a Neutral Good character, who is in disguise, a question in LE which the NG character won't understand, revealing his attempted deception.
Finally, consider the town where the alignment and worship are paramount. Getting the PC of the same alignment to talk to the townspeople in that tongue can give a reaction bonus, if the DM allows it. (And in a campaign where the DM is emphasizing alignment, I would think he would allow it.)