Open Game Systems
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 freely as long as I respect the terms of each individual license.
The following systems are available under an open license and are thus free to use for any activity, from playing to publishing new products (books, video games...) using the system. Note that details may vary from license to license so make sure you read and understand its details before using a system.
- Original OGL
- D&D 3.5 SRD, Dungeons and Dragons system reference document
- Pathfinder OGL 1.0a
- Modern d20 SRD
Note that the official d20 SRD for D&D 3e has been revoked. It has been replaced by Paizo's Pathfinder SRD, which is compatible with previous d20 material and still being used for publication of new products by the community by many companies.
d20 System based
- 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)
- Iridium System
- Open Core Roleplaying System - uses Open Content from several OGL systems
- Runic, Runequest RPG
- Spellchrome (OGL and Non-Open Game Content)
- Fantasy Craft (OGL)
Retro-clones are new games that are compatible with older games now out-of-print, allowing for the use of previous material without having to acquire a possibly rare and/or expensive copy of the original game or resorting to piracy. These are part of a larger movement known as the Old-School Renaissance (OSR).
- 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)
OGL with 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
Creative Commons licenses
- 6d6 RPG 6d6 Fireball (Attribution-Share Alike)
- Eclipse Phase Posthuman Studios (Attribution-Noncommercial-Share Alike 3.0 Unported License)
- 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)
- Lady Blackbird (Attribution Non-Commercial Share-Alike)
- Iliamna Unknown (Attribution Non-Commercial Share-Alike)
- Saga, a rules-light narrative universal system (Attribution/Non-Commercial/Share-Alike)
- Jumpers, a multi-dimensional, multi-genre sci-fi RPG (Attribution-Noncommercial-Share Alike 3.0 Unported License)
- 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)
- 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)
- The Far Towers (Public Domain)
- Hoard 1st Edition and Microcosm (Public Domain)
- Theonosis, an open fantasy setting - The Open Setting License allows the setting to be used with any game.
- List of open tabletop games at the FOSsil Bank wiki.