Imagine you want to sell a rare comic book to a group of friends, but you have no idea how much each one is willing to pay. Can you design a bidding process that gets you the highest possible price, even though every friend is looking out for themselves? That’s the core of mechanism design—a branch of game theory where we act as the rule-maker, not just a player. We build the rules so that self-interested people end up doing exactly what we want.