What system was developed by Margaret Weis Productions was used in a game based on the Supernatural TV series?
Cortex System: The Cortex System is a generic RPG system based on the "Sovereign Stone System ", and was developed by Margaret Weis Productions, Ltd for the Serenity Role Playing Game. Supernatural Role Playing Game: The Supernatural Role Playing Game is a role-playing game by Margaret Weis Productions that was released in 2009.
i don't know