Open Game License


The Open Game License 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.

Language of the license

The OGL describes two forms of content:
Open Game Content
Product Identity
Use of another company's Product Identity is considered breach of the licensing agreement.

Background

The OGL was originally published by Wizards of the Coast in 2000 to license the use of portions of the third edition of Dungeons & Dragons, via a System Reference Document, thus allowing third-party publishers to produce compatible material. This move was spearheaded by Ryan Dancey. Publishers could also use the separate d20 System Trademark License to include a logo indicating compatibility.
In June 2008, Wizards of the Coast transitioned to a new, more restrictive royalty-free license called the Game System License, which is available for third-party developers to publish products compatible with Dungeons & Dragons 4th edition. The GSL is incompatible with the previous OGL. However, by its own terms the OGL is irrevocable, and remains in widespread use.
On January 12, 2016, Wizards of the Coast released the 5th edition SRD under v1.0a of the OGL, marking a return to the Open Gaming format.
Those individuals, groups and publishing companies that license their works under the OGL and similar documents are sometimes collectively referred to as the "open gaming movement".