The Erwinian Roleplaying System was initially created by my father, Eric Erwin, in the 1980’s. Expanding on his love of roleplaying, Eric (and later with his father, Jim) developed a slick and impactful RPG system, creating several expansive settings along with the initial core rules. He refined the “core” settings into the four great genres which characterize most systems: Fantasy, Science Fiction, Historical/Alternate History, and Post-Apocalypse! Later, Emma Erwin added her own setting: Nihimana.

I later picked up the books and formatted them along universal guidelines so that I could share my father and grandfather’s work with the world. This system has brought countless hours of fun and creativity into the lives of my family and our friends, and now it is finally available online after many years.

With new artwork by three of the Erwins, years of playtesting by friends and family, and an official release on DriveThruRPG, I am proud to present The Erwinian Roleplaying System!

The Erwinian System can be found on DriveThruRPG on our publisher page!

Art by myself, Emmett Erwin, and Emma Erwin.

The Erwinian Roleplaying System is a universal RPG framework. It has hints of “Old School” mixed in with the simpler design sensibilities of the modern tabletop age. Characters are capable of great power and achievement, while also maintaining the right amount of vulnerability that makes for a challenging experience.

The system uses an intuitive system we call d20/d%. Essentially, the system allows for easy probability calculation and intuitive mechanical use. Every 1 on a d20 converts to 5% on a d%, allowing for fast conversion between the two. The math was designed to be adaptable in the rules as written, but also to allow the GM and players to easily create their own rules! This is a framework, after all. The system is easily hackable and we encourage players to have a great time with creating their own ideas!

If you’re interested, be sure to check out my Itch.io page as well! It’s not just giant multi-generational RPGs I work on; it’s Micro-RPGs too!