Be an animal, meet an animal, and touch hands at a critical point in your conversation. A simple prisoner's dilemma will tell you if there was trust in the exchange.
Implied universes are Reynard the Fox, Fables, The Borrowers / The Littles / Arrietty, Yakari, Miyori no Mori, Kirikou, etc.
(cover art by anon)
If you use this game, I'm confident you'll be considerate enough to come back and drop... [click here for more]