From the Introduction:
The role of a game master ("GM") running a tabletop roleplaying game can be a tough one. Not only do they have to maintain a handle on the stage they are setting, but they also have to keep things interesting. A lot of times a GM will look towards a pre-made adventure - many of which require players to do A then B then C to get D, etc. - to save some time in the game preparation. Just as many times, players will start at A then send their characters to X, destroy C, and then run away from D to get to M. All the GM's planning in the world cannot account for every action the players want their characters to take.
Perhaps the worst situation in which a GM can find himself results when a player character ("PC") is trying to have an unforseen conversation with a non-player character ("NPC"). For example, the Mayor that Dooley wants to meet. The GM could just ignore the player's request and say that the Mayor says nothing interesting. Another GM could use the Mayor to get the PC's back on track with the prepared adventure. A GM could take a break to flesh out the area the PC's want to explore.
This supplement attempts to help a GM create interesting NPC's on the fly so that if the third option is taken, the task is simpler and the results fun. Instead of just a stereotypical Mayor (whatever that may be), with a few die rolls a Mayor can be created with a history, motivations, and even a reason to speak with the PC's. The best part is that this supplement is universal. It was designed to work for every genre from fantasy to horror, space opera to post-apocalypse adventure.