"Open gaming is the movement within the role-playing game (RPG) industry that is somewhat similar to the open source movement. The key aspect is that authors give recipients of the work a license to certain rights, such as the right to make copies or the right to create derivative works, under particular conditions. All open gaming therefore depends upon a license." (http://en.wikipedia.org/wiki/Open_gaming)
Furthermore there exists a similar trend within the board game community: "Print-and-Play", downloadable and printable board games.
The following are considered open games (listed in alphabetical order):
- Action! System, published by Gold Rush Games
- Circe roleplaying system, published by WorldForge
- Dominion Rules Explicitly encouraging the creation of new skills, spells, beasts and rules by its modular structure, this project attempted to establish an equivalent to the Open Source Software model in RPG gaming.
- FATE, Fantastic Adventures in Tabletop Entertainment
- Four Colors al Fresco by Woodelf
- Fudge System Reference Document by Grey Ghost Games
- Labyrinth Lord by Goblinoid Games
- OGL System by Mongoose Publishing
- Conan The Roleplaying Game
- Lone Wolf
- OGL Rulebooks
- OSRIC by Stuart Marshall and Mathew Finch
- System Reference Document, which is a subset of the d20 System by Wizards of the Coast
- RuneQuest: the current version of RuneQuest (as of 2007), by Mongoose Publishing
- T10 systemet introduced by Swedish role-playing company Rävsvans
- Traveller (role-playing game) by Mongoose Publishing
- Violence: the RPG of egregious and repulsive bloodshed by Greg Costikyan.
- Yags by Samuel Penn.
Print and Play