I’m starting to write a book that I’ve been wanting to do for a long time. It takes place in the Forgotten Realms scenary, in addition to using elements and creatures from Dungeons And Dragons, and I don’t know if it is legal to publish something like that. If it's non-fiction (game lore), it should be legal to publish through the DM's Guild, if you follow the guidelines. If fiction, you'd have to get it licensed from Wizards of the Coast (as HarperCollins did for R.A. Salvatore's current trilogy) or you can't legally publish it.
— Ed Greenwood (@TheEdVerse) April 22, 2020
From what I read, it is not yet possible to publish books or novels in the DM’s Guild. So in that case, would it only be possible to publish the book with Wizards’ consent? Yes, you would have to make a successful proposal to Wizards, and secure a license from them to do so. (As HarperCollins did, for the current Drizzt trilogy.)
— Ed Greenwood (@TheEdVerse) April 22, 2020