Worldbuilding Magazine is a free PDF magazine dedicated to, well, worldbuilding, “the process of constructing an imaginary world. It currently comes out on a bi-monthly schedule.
There’s also a weekly podcast associated with the magazine, Worldcasting.
Just an all around excellent resource if you’re into that sort of thing.
The Realm Generator is a Python program that randomly generates hundreds of noble families for use in pen-and-paper roleplaying games.
If you’ve ever played a tabletop roleplaying game, then you may have encountered a common problem: you haven’t got the time to invent a realm. And I don’t mean a realm with a single great dynasty in it; I mean hundreds of noble families, thousands of nobles and courtiers, complex relationships between them, feuds, alliances, loose factions, hierarchies…it’s work.
That is, it was work. Until now. Presenting…
In a single click, you can generate a complex, interwoven realm filled with intrigue, ready for any tabletop gaming experience.
Ironsworn is a tabletop roleplaying game that is designed to be played solo, co-op, or traditionally with one or more players and a gamemaster.
. . . you are a hero sworn to undertake perilous quests in the dark fantasy setting of the Ironlands. You will explore untracked wilds, fight desperate battles, forge bonds with isolated communities, and reveal the secrets of this harsh land.
Are you ready to swear iron vows and see them fulfilled—no matter the cost?
The game and its supplements are available to download for free, and is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike license (there’s even an Ironsworn System Reference Document for commercial works using the system).
Of course, there are also some beautiful looking print versions of the books available at DriveThruRPG.
Etsy seller MarsDice makes this honest D20.