Don't play the game, game the player
As I was leaving work the other day, my "people leader" (a term that deserves a post all to itself, but translates to "manager") was quipping about a trick he'd used to win a Rock-Paper-Scissors tournament and how, despite its simplicity, people were taken in again and again.
All he did was suggest, before each bout, a play to the other player by visibly making the motion in front of them, but disguised as something else. For example, he might put his flat hand to his face thoughtfully, with his fingers split apart either side of his nose suggesting scissors.
Apparently these simple cues are surprisingly reliable.
In a similar vein, I've been watching a video podcast called "Scam School" which pulls back the curtain on simple pub wagers. Most of these are misdirections that, once revealed, are extremely obvious.
It all comes down to the fact that the human mind while complex, is at the same time fairly routine and predictable. If you can make something unexpected look like something normal, we'll accept it without question. This is how con men work.
It's also why witnesses are unreliable; when the brain is confronted with new and seemingly incongruous data, it will attempt to apply known patterns to make sense of it. Since everyone's life experience is different the patterns applied vary and so the interpretation of events from a number of different witnesses can vary wildly.
What I learned from this is, the easiest way to achieve an outcome from another person is to make them want the same thing you do and it can be remarkably simple to do so.