Open Game Systems

This page collects all the games under an open license like the Open Game License and various Creative Commons Licenses.

Definition: What is an Open License?

This page operates under the following definition:

"An Open License allows the free and perpetual re-use of original material by anybody willing to follow the restrictions of said license, without an explicit contact or negotiation between original author and licensee."

In other words, if something is available under an open license, I can use and re-use it for free, as long as I respect the restrictions laid out in the license, without having to contact the author.

Retroclones

Retro-clones are new games that are compatible with games that are now out-of-print. They are listed separately to the other games.

The List:

The following systems are available under an open license and are thus free to use in your own publications. (Though with varying restriction on the use of the material.)

D&D Open Game License

(Direct Link)

• d20 System 3.5 SRD, Dungeons and Dragons (OGL and d20 System License - revoked)
• Modern d20 SRD

Retro-Clones

• OSRIC for 1E AD&D (download) (OGL and OSRIC Open License)
• Labyrinth Lord for B/X D&D (download or view wiki) (OGL and Labyrinth Lord Trademark License)
• BFRPG, Basic Fantasy Role-Playing Game, for B/X D&D
• Swords & Wizardry for 0E D&D (download) (OGL and the Swords & Wizardry Compatability Statement License)
• Swords & Wizardry Whitebox for Whitebox D&D (download) (OGL and the Swords & Wizardry Compatability Statement License)
• Warrior & Wizard for The Fantasy Trip (download CC or OGL version or view wiki) (Creative Commons Attribution-ShareAlike and OGL; Direct link to file)

d20 System Based OGL

• d20 Anime SRD (direct link to file)
• Wayfarers (OGL and open-ended agreement)
• Prometheus SRD (OGL and Prometheus License)
• Mutants & Masterminds (OGL and M&M Superlink)
• True20 (OGL and True20 Adventure Roleplaying Trademark License)

Other Systems Using OGL

• Iridium System
• Open Core Roleplaying System - uses Open Content from several OGL systems
• Runic, Runequest RPG
• Spellchrome (OGL and Non-Open Game Content)

Open Game License and Trademark License

These games release their material as Open Game Content, but also provide another, more restricted, license to allow publishers to refer to Product Identity.

• Mutant Future (OGL and Mutant Future Trademark License)
• GORE (OGL and GORE License)
• FUDGE (OGL and FUDGE System Trademark License; also under its own license)
• vsM Engine

Fudge based

• Fate 2.0 (direct link to the file)
• Spirit of the Century

Creative Commons Licenses

• Drowning and Falling (Attribution/Non-Commercial/Share-Alike)
• The Shadow of Yesterday (Attribution)
• Donjon (Attribution/Share-Alike)
• Wushu Open (Attribution)
• Wushu Open Reloaded (Attribution/Share-Alike)
• Shadows (Attribution)
• Myriad (Attribution)
• Organic Rules Components (ORC) (Attribution)
• Violence (Attribution/Non-Commercial/Share-Alike)
• Star Wreck (Attribution/Non-Commercial/Share-Alike)
• Noteworthy (Attribution/Non-Commercial)
• Executive Decision (Attribution/Non-Commercial/Share-Alike; direct link to file)
• ...in Spaaace! (Attribution/Non-Commercial/Share-Alike; direct link to file)
• Sufficiently Advanced (Attribution/Non-Commercial)
• Treasure (Attribution/Non-Commercial/Share-Alike)
• The Simple Game System (TSGS) (Attribution/SHare-Alike)
• Danger Patrol (Attribution/Non-Commercial/Share-Alike)

GNU licenses

• Gods and Monsters (GNU Free Documentation License)
• Circe (GNU Free Documentation Licence and GNU General Public License)
• Fringe (OpenOffice Writer format) (GNU General Public License)

Other

• Dominion Rules (Dominion Rules Licence)
• Action! System (Action! System Open License)
• Active Exploits (Active Exploits Distribution and Expansion License)
• Redbox Hack (view wiki) (license unclear; readers told to "do what you'd like with the thing").
• Dungeons and Dragons Fourth Edition (Game System License)
• Fire and Sword 4E (Free Art License)
• 4C System for the Marvel RPG (download) (Public Domain; Direct link to file)