The Grimdark Drinking Game

Every fantasy story and most sci-fi has something dark or grim in it. When does it hit the boiling point and become "grimdark"? When you feel like it does. Every reader has their own standards of dark and gritty. Alternatively, it's whether the AUTHOR says they're grimdark.

Still, I think this is a subject which deserves to be handled by a checklist of common factors which can tell you whether or not a work is grimdark or not? A work can be grimdark if it has all of these or none of these but...