In D&D, the DM decides how to use the rules in play.
The rules say many things. The DM determines in the moment how those things play out. #DnD
— Jeremy Crawford (@JeremyECrawford) January 28, 2019
I think the solution is clearer rules and less ambiguity and GM fiat, myself. If the rules don’t provide a clear direction for handling weird or ambiguous cases, there is something missing in the rules. I mean I know it’s popular now to go the “rulings not rules” approach in the absence of an actual rule or mechanic to support something, I feel as if a well designed game at the very least provides a go-to mechanic to resolve anything.
— Cam Banks (@boymonster) January 29, 2019
Have an edge case in D&D and can't find a rule for it?
The game has a go-to rule for you: call for an appropriate ability check, attack roll, or saving throw and use advantage/disadvantage.
For more info, see "Using Ability Scores" in the "Dungeon Master's Guide" (p. 237). #DnD https://t.co/mKqaDJA8V8
— Jeremy Crawford (@JeremyECrawford) January 29, 2019
See, that’s exactly what I’m talking about. D&D *does* have an existing system structure that helps you resolve edge cases. So why not say that instead of the “rulings not rules” narrative? Unclear to me. It's in our rulebooks. It doesn't get more official than that.
— Jeremy Crawford (@JeremyECrawford) January 29, 2019
I’m speaking here about the narrative outside of the books of a DM just making up whatever they like if the rules aren’t there to resolve a situation, which seems at odds with the book’s actual provision of a go-to rule for just such situations. I can't speak to narratives people might have about the game. I'm pointing to what's actually in it.
— Jeremy Crawford (@JeremyECrawford) January 29, 2019
“The DM decides what rules to use” makes me think that you’re suggesting any rule is fine so long as the DM likes it, even if it’s a coin toss. Which, well, sure. But I assume you mean “the DM knows what the rules of the book are and how to use them appropriately”? Are you referring to me saying the DM decides how to use the rules? That's me paraphrasing the introduction of the "Dungeon Master's Guide."
— Jeremy Crawford (@JeremyECrawford) January 29, 2019