Be Predictable

Sometimes predictability can work in your favor: By creating a pattern for people to be familiar and comfortable with, you can lull them to sleep. They have prepared everything according to their preconceived notions about you. You can use this in several ways: First, it sets up a smoke screen, a comfortable front behind which you can carry on deceptive actions. Second, it allows you on rare occasions to do something completely against the pattern, unsettling your opponent so deeply he will fall to the ground without being pushed.

“The enlightened ruler is so mysterious that he seems to dwell nowhere, so inexplicable that no one can seek him. He reposes in non-action above, and his ministers tremble below.”
~ Han-fei-tzu, Chinese philosopher, third century B.C.

Reference: THE 48 LAWS OF POWER by Robert Greene