Boomflinger

If you or a permanent you control assembles a Contraption and your Contraption deck is empty, nothing happens. You don't lose the game.

In silver-bordered games using Contraptions, you have three sprockets, illustrated on the back of Contraption cards. At the start of the game, put a CRANK! counter on sprocket 3.

While Contraptions you control are on the battlefield, the Contraption deck is not, even if you are using it to signify the three sprockets.

In Limited formats, a Contraption deck may include any number of Contraption cards in your card pool. You don't have to include every Contraption card you draft or open in sealed deck. In those formats, your Contraption deck may include duplicates.

At the beginning of your upkeep, if you control any Contraptions, move the CRANK! counter to the next sprocket. You may then crank any number of Contraptions on that sprocket, causing their abilities to trigger. Cranking a Contraption is always optional.

In Constructed formats, a Contraption deck must have at least fifteen different Contraption cards and no more than one of each.

Any Contraption that's on the battlefield and wasn't assembled immediately heads to the scrapyard. However, if it's a not an actual Contraption card (like Copy Artifact isn't), it goes to your graveyard as normal. Non-Contraption cards can't be in the scrapyard.

Contraptions aren't put into your main deck. They go into a separate deck called the Contraption deck.