The VOIDRUNNER'S CODEX is coming! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
I think you meant hyperbole (exaggerated statements or claims not meant to be taken literally) rather than metaphor (a figure of speech that implicitly compares two unrelated things, typically by stating that one thing is another).
If it was a metaphor then you would be saying have a coronary...
While I agree you can have red herrings, I think often in RPGs they tend to fall flat, unless they can discover it is an actual deliberate misdirect by the villain. If it just is a misleading clue that leads to a dead end, players can feel like they have just wasted time.