Attaching affects two cards at once. 1. One card will be designated as the one being Attached, and thus become Attached. The other will become the Top-Most Card.
§ 434.1.a Core Rules PDF (officieel)
§ 434 Attach
§ 434.1 Attaching is the act of linking two cards on the board together to combine their effects in some way. This causes one or more cards to become Attached and at least one card to become a Top-Most Card. See rule 716. Attachment for more information.
