Anthony Davis said:
The sole feature that exists, outside of the character itself, that determines personality, is the assigned dialog file. How would it be humanely possible to create an unknown number of dialog files that can all interact with each other and still not seem shallow?
We have talked about many options, for example like maybe assigning a dialog file based on the characters background feat, but what if the player doesn't choose one?
hmm come to think of it there could be another way.
like f.e. player creates a custom non-main character.
he chooses stats, feats, abilities, appearance etc.
then the time comes to choose the alignment.
and here you can ask him whether he will prefer to assign a personality to this character or not - if not he chooses the alignment normally and his character won't have a premade personality - if yes - you show him the list of pre-made dialog files based on alignments like
Personalities:
1. Char Name, Neutral Evil, a short background info (just to give a feel of the personality)
2. Char Name, Lawful Good, a short background info
3. Char Name, Lawful Neutral, a short background info
...
which will set an alignment to the character as well.
this way you won't have to create hundreds of dialog files - but at least 5 or 6 will do a nice job (and I doubt that you will create a party entirely of a single alignment chars) and it will be easy to get away with a personality based only on an alignment and still not make it to look shallow.
of course depending on char's class some options will be "grayed out".