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The Simple Interaction Notation System, or SIN System, is a generic set of rules for running a narrative Role Playing Game (RPG) session or campaign.

To use the SIN System, you’ll need a stack of 2-sided tokens. Coins will do, but a particular type of token with black on one side and white on the other works best. You’ll need a Doyen, or storyteller, and one of more players. Other than that, you will need a piece of paper for your character and the Core Rules.

SIN System games, at their core, are narrative games. They are also just that, a game. The most important thing is to always make sure you are having fun. Please make sure to use proper RPG safety tools to ensure the maximum comfort and enjoyment of everyone involved. For more information check out

SIN System Core Rules Updated: August 25, 2022

otHELLo EXAULT/SIN Open Beta Test

otHELLo Cover
otHELLo: EXAULT/SIN is a narrative, sci-fi, horror RPG where players take the roles of EXAULTED in a space station infected with an unknown entity called SIN. This is the first game using the SIN System I've been developing.

The following rules are presented in an unfinished state for open beta testing. I hope you enjoy the game, and I look foward to your feedback. Feedback can be sent to rkalajian [at], or can be postd on the RPGGeek Forums for otHELLO: EXAULT/SIN.

otHELLo: EXAULT/SIN Open Beta Rules Updated: July 27, 2022

This page will serve as the main hub for the beta test, and will contain all future updates over the course of the testing period.

Coming Soon:

otHELLo Sourcebook: New Dehlikyo

New Dehlikyo Cover
Explore the largest city on the OTHELLO VII space station with its giant spacescrapers and almost infinite depths.

otHELLo: EXAULT/SIN New Dehlikyo Sourcebook Beta Updated: July 28, 2022

This sourcebook is a work in progress

Center St.: otHELLo

otHELLo Corridor

A guide for creating a space station for otHELLo using the SIN System's Center St. module.