DUNGEONS & DRAGONS co-creator Dave Arneson has passed away Tuesday, according to multiple news outlets.
Arneson and co-creator Gary Gygax developed the game now known as D&D starting in 1969, publishing it first in 1974.
WIRED reports that Arneson, 61, lost his battle with cancer, surrounded by his family in St. Paul, Minnesota. Gygax died about a year ago.
Arneson was a driving force behind D&D, transforming Gygax's CHAINMAIL into the first edition of the role-playing game. He later sued to get credit for his contributions against Gygax, but resolved the issues and worked with him again in the mid-1980s.
Arneson later worked as a teacher, educating about the uses of role-playing games in education, and taught multimedia at private university Full Sail in Florida.
