A long list of CC-licensed tabletop role-playing games and wargames for your hacking pleasure. Some are best-sellers, others are indie diamonds, and others have some room for improvement (maybe you're up to the task?). Most are CC-BY-4.0, but some have SA or NC terms---as always, be sure to read the docs!
"The procedures for traveling and delving are altered versions of the Hazard System v0.3 designed by Necropraxis and are made available via Creative Commons Attribution 3.0 Unported license."
CC-BY-SA
Not a game, but a tool to quickly sketch a layout.
An intro section for your complete book when you don't know how to describe your oral tradition to a newcomer.
