This site is primarily dedicated to material concerning the derro, a race of subterranean adversaries for the Pathfinder RPG (and to a lesser extent by necessity, 2E / 3E and 3.5E of Dungeons and Dragons before that).
At least according to this video, my initial impressions of 4E are probably on target so I’m just going to pretend that travesty of a tabletop RPG (using the term loosely) doesn’t exist and keep moving… OK, I will link to any 4E specific material I find for the sake of completeness.
I’m not familiar with 5E at the time I write this, so I can’t really comment on that further until I pickup the basics and work out where derro feature.
It is a work of fiction, and all material herein is covered by this particular version of the Open Game Licence. You are therefore free to use any of this material under the terms and conditions of this licence.
PS follow the link for my Ars Magica 5th edition site My Life as a Grog