incompatible with the previous OGL as many publishers suggest this restriction represents a direct attack on the OGL which WOTC is legally unable to revoke. This restriction has fostered some negative feelings within the RPG communities against the leader and resulted in many publishers who previously supported the d20 system to reject the 4th Edition of D&D entirely. As a consequence, a lot of publishers which were previously adopters of the d20 system decided to develop their own set of rules based on elements of the OGL and publishing their own material under the OGL". Bob Byrne, for Black Gate in 2015, commented that the GSL "drove out nearly all third party producers for the to-be short-lived 4th Edition. Two of them, Goodman Games and Mongoose Publishing, signed on for 4th Edition, though to not much benefit for themselves. [...] Necromancer effectively packed it in, while Paizo created Pathfinder to compete directly with Wizards' new version of Dungeons & Dragons". References Dungeons & Dragons Public copyright licenses