The Open Gaming License or OGL for short, was written by Ryan S. Dancey to facilitate Open Gaming as a viable non-profit initiative. It is now the main license supported by the Open Gaming Foundation (OGF) which was also started by Dancey.

Modelled on the ethos of the GNU General Public License, the OGL requires that

  1. The license must allow game rules and materials that use game rules to be freely copied, modified and distributed.
  2. The license must ensure that material distributed using the license cannot have those permissions restricted in the future.
According to the OGF:

The first requirement precludes an Open Gaming License from placing any limitation on the licensed content beyond those necessary to enforce the terms of the license itself. This prohibition includes a restriction against commercial distribution, a requirement for review or approval, the payment of a fee of any kind to a 3rd party, or any other term that would seek to limit the free use of the licensed material.

The second requirement means that the license must have a mechanism to ensure that the rights it grants cannot be taken away, either by the original contributor of the material, of the copyright holder of the license text itself, by an action taken on behalf of a 3rd party, or any other process.

Violation of an Open Gaming license can result in legal action from any of three parties (taken from http://www.wizards.com/D20/ ):

  1. Anyone listed in the COPYRIGHT NOTICE section related to any Open Game Content you copied, modified or distributed.
  2. Anyone who receives Open Game Content from you and relies on you to ensure that your work conforms to the terms of the License who subsequently discovers problems with the Open Game Content they received from you
  3. Someone with a copyright or trademark interest in the work you've distributed, even if you did so while relying on a previous publisher's representation that they had followed the terms of the License.
Licenses that fall under the general tenents of the OGL are:
  • The Open Gaming License drafted by Wizards of the Coast
  • The Dominion Rules License drafted by Dominion Games
  • The GNU General Public License, and the Free Documentation License drafted by the Free Software Foundation
  • The Open Content License by OpenContent qualifies as long as neither of the License Options in Section VI of the license are used.
  • The October Open Game License by the RPG Library
However, it should be noted that there is no formal endorsement of said licenses.

Sources and further information:
http://www.opengamingfoundation.org
http://www.wizards.com/D20/

Any advice, corrections or requests are most welcome. Please /msg me