Tinker

The cheat at the center of every artifact combo deck for a quarter-century, and the reason so many artifacts get restricted before they ever threaten a fair format. The trick is in the exchange rate: you sacrifice a worthless trinket as part of the cost, then search your whole library and put any artifact card straight onto the battlefield. The sacrifice clause was clearly intended as a brake, the design discipline meant to keep the card honest by demanding an artifact already in play. It does not work, because the floor of "an artifact" is a zero-mana token or a Lotus Petal, while the ceiling of "any artifact card" is whatever the most broken construct in the format happens to be. That gap is what made Tinker one of the defining enablers of big-artifact decks, where the standard line ramps a one-mana rock into a game-ending threat several turns ahead of its cost. The card has spent most of its life restricted in Vintage and banned in Legacy precisely because no rate of sacrifice can offset turning trash into treasure: you tutor and cheat in the same motion, and the spell never has to pay the difference. It is the purest statement of a problem artifact design keeps circling back to: the moment you let a spell put a card directly onto the battlefield and read "any artifact," the mana cost stops describing what you are actually buying.