I am astonished that the team behind D&D 5e, under WotC, came up with the advantage/disadvantage mechanic. It's just about the only example I know of a market leader *actually* bringing an innovation to the table. Surely they took the idea from some poor unknown publisher who languishes in a basement, right? But I've never heard such accusations.
The Wandering Shop is a Mastodon instance initially geared for the science fiction and fantasy community but open to anyone. We want our 'local' timeline to have the feel of a coffee shop at a good convention: tables full of friendly conversation on a wide variety of topics. We welcome everyone who wants to participate, so long as you're willing to abide by our code of conduct.