What WotC 5e D&D content am I and am I not allowed to use in published 3rd-party content? Core books? Books like Xanathar's and Volo's? Unearthed Arcana? How do I avoid plagiarism, copyright infringement, etc?
Right now, I want to provide on my site/blog short campaign settings for dungeon masters to use as starting ideas for their games. If I create enough, I'm considering package them together in a PDF and sell them on something like DriveThruRPG.