Historical Rules · 18 June 2021
Rule 711.1
Official source text from the 18 June 2021 Rules release
A double-faced card has a Magic card face on each side rather than a Magic card face on one side and a Magic card back on the other. There are two kinds of double-faced cards. Transforming double-faced cards include abilities on one or both of their faces that allow the card to “transform” (turn over to its other face) or allow the card to enter the battlefield “transformed” (with its back face up). Modal double-faced cards have two faces that are independent from one another and can’t transform.