For those that missed the Saga, DnD 5E is now in the creative commons after Wizards cast a wish spell to undo their multiple nat 1s.
Dungeons & Dragons' publisher will put the game under a Creative Commons license; TechCrunch
DnD’s core mechanics have been provided under the OGL, Open Games License, that have allowed people to build careers out of it. DnD is getting pretty big and it’s not just paper roll playing, people cosplay characters and run acted out campaigns, selling merchandise and other wares. With the upcomming movie and new rule set Wizards of the coast wanted their extra piece of the pie, creating a new OGL that would retroactively replace the old one (which is apparently legally questionable), give them more control over content and a percentage of the revenue from people who make over a certain amount.
It leaked and people freaked, many cancelled subscriptions to their online game building service, creators made videos about how to get into new systems, it was a whole thing.
After multiple attempts to clarify and then rewrite the new OGL, Wizards realized their only real play was to give up, and has released the core mechanics into creative commons in hopes people might stop jumping ship right before their big movie.