- D's want power
- I's want fun
- S's want stability
- C's want correctness
Because these four personality types include goals, they strike me as being an easy, quick way to give NPCs depth, especially if each NPC's second dominant personality type is included. Potentially, it could take just the roll of a d4 or two to make sure that NPCs feel different from each other to players. I don't have time to investigate more before I fly out for a wedding (so no more posts this week), but this definitely merits further thought.
Have you ever seen or used real-life personality tests, or another method altogether, to give NPCs depth and make them feel different from each other to players?