Open Game License
Public copyright license for tabletop role-playing games / From Wikipedia, the free encyclopedia
For the UK government publication license also abbreviated OGL, see Open Government Licence.
The Open Game License (OGL) is a public copyright license by Wizards of the Coast that may be used by tabletop role-playing game developers to grant permission to modify, copy, and redistribute some of the content designed for their games, notably game mechanics. However, they must share-alike copies and derivative works.