I have never done this in the past, but then again I’ve never worked on a TTRPG adventure which leaned on NPC interactions being a critical part of the plot.

I sat down and hashed out an adventure for The Secret World TTRPG and after getting the bones of the story in place (first draft!) I considered the key NPCs who would be crucial to the plot. TSW: The Video Game was big on NPCs, and unlike any other MMO I have ever played, many of these have stuck with me throughout the years. That’s in part because TSW was as much about the characters as it was the mechanics.

To keep with this tradition, and because I love TTRPGs which task the players with more investigation and interaction than combat, I figured that building the adventure around a “small town dynamic” would bring in that “Kingsmouth feel” that I know and love from TSW. To get that, I’d need to know how NPCs would react to one another, so I started this: the relationship matrix.

I have a stable of key NPCs, and used the Canvas plugin for Obsidian to create a “Punnett square of characters”. At each intersection, I have another document which focuses on the relationship between the two participants. While this means that each relationship is technically listed twice, that’s OK since it’s more of a quick-access kind of thing that will tell me the following at a glance:

• How one character will act towards another, and why.
• How one character will report another character to the player agents.
• How one character will react when something happens to another character.

Along the way, as each character’s relationship is written, I am finding out things about individuals that I’d otherwise have to either think up out of the blue, or scramble to concoct in the heat of the moment while playing the game. I’m hoping that this interpersonal matrix will help me understand each key character better and, in the process, write a better adventure.