I’ve played enough D&D to know a Dragon hiding themselves with Illusion magic when I see one. Just leave your gold as tribute and don’t look’em in the eye.
Secret confession time… don’t tell my players….
Sometimes I put a cat on the map and when they get close to it, do a “random” awareness check for shits and giggles.
And when they roll a Nat 20?
Depends on my mood?
Once the cat decided to adopt the humans (and conveniently eats all their snacks and maybe chugs their potions?)
(They may have fed the cat.)
See, this is why stray cats are such pests. Always jumping on roofs, and destroying them! I’m just trying to enjoy my hot pocket. Suddenly my ceiling is caving in!
And bridges! They just walk across that bridge and sympathetic resonance and boom.
No bridge.
That’s a dragon.