Mechanism Design
The reverse of ordinary game theory: instead of starting with a fixed set of rules and predicting what a rational player will do, mechanism design starts with a desired outcome and works backward to design the rules, procedures, and incentives that will lead self-interested players to produce that outcome anyway. The FCC's simultaneous ascending spectrum auction and Roth's strategy-proof school-matching algorithms are both examples of redesigning the game rather than appealing to players' better nature.