In the open gaming movement, a System Reference Document (SRD) is reference for a role-playing game's mechanics licensed under the Open Game License OGL to allow other publishers to make material compatible with that game.
The first SRD was published in 2000 by Wizards of the Coast (WotC) and based upon the third edition of Dungeons and Dragons. That SRD formed the basis of WotC's various d20 systems role-playing games, including d20 Modern and d20 Future. The SRD is also the basis for role-playing games published by companies other than WotC, including Mutants and Masterminds and the Pathfinder, among others.
List of SRD for various systems
- Dungeons & Dragons 3rd Edition SRD the first and original
- Dungeons & Dragons 5th Edition SRD
- D20 Modern SRD
- Pathfinder SRD
- The 13th Age SRD
- FATE System SRD
- GUMSHOE SRD
- Mutants and Masterminds SRD
- Spirit of the Century SRD
- Traveller SRD