Game System License

The Game System License is a license that allows third-party publishers to create products compatible with and using the intellectual property from the 4th edition of "Dungeons & Dragons" ("D&D"). It was released to the public by Wizards of the Coast (WotC) on June 17, 2008.
A System Reference Document (SRD) of the 3rd edition of "D&D" had been licensed under the Open Game License (OGL). The OGL is a copyright license, allowing the use of copyrighted text created by others in one's products. Also released at the same time was the d20 System Trademark License, allowing third-party publishers to indicate compatibility using a system logo, but not allowing the use of the "D&D" trademark.
The GSL, however, grants use of the 4th Edition System Reference Document, which lists trademarks, words, and short phrases that could be used to refer to materials in the "Dungeons & Dragons" 4th edition rules, but contains no rules itself. People wishing to use this license are also granted a logo that must be placed onto their products to state that they are compatible with "Dungeon & Dragons" 4th Edition. The license also can be updated by Wizards of the Coast and updates affect all licensees; in case of litigation the licensees must pay the legal costs of Wizards of the Coast.
After reviewing the terms and conditions of the GSL, Necromancer Games co-founder Clark Peterson declared it "an unmitigated disaster", and that his company would cease its efforts to support the new edition. Prior to Gen Con 2008, it was announced that the GSL was undergoing a revision. Shortly after the end of the convention a number of Wizards of the Coast's jobs were eliminated, including the Licensing Manager position that was held by Linae Foster.
With the release of the 5th edition of "D&D" in 2014, and the release under the OGL of an SRD for that edition, the GSL fell into disuse, though it remains the only license for 4th edition.