Stratagem 27: Feign Madness, but Keep Your Balance or Pretend to be a Pig in order to Eat the Tiger or Play Dumb or Feign Ignorance and Hide One’s Intentions
Identification
Let them underestimate you.
Example
Playing dumb early in a negotiation makes your opponent lazy, so that you can put your real plan into motion without suspect.
Solution
Look at someone’s history before you get comfortable.