Fast land

The fast lands, or fastlands^[1], are a double cycle of taplands.^[2] The allied color lands were featured in Scars of Mirrodin. The enemy colored cycle was later introduced in Kaladesh.

Description[ | ]

These lands produce two colors of mana and enter the battlefield tapped unless you control two or fewer other lands.^[3]

Wizards of the Coast originally only referred to this cycle as scar lands, after the first set they appeared in, though several nicknames were quickly proposed by the Magic community. WotC finally adopted fast lands as the preferred name.^[4]

The fast-manland cycle in Dungeons & Dragons: Adventures in the Forgotten Realms have a similar clause, but enters tapped if played as the third land rather than the fourth. Rather than generating two colors, they can animate themselves into a creature.

The Slow lands of Innistrad: Midnight Hunt are a mirror of the fast lands. They enter the battlefield tapped unless you control two or more other lands.

Rulings[ | ]

If one of these lands is your first, second, or third land, it enters the battlefield untapped. If you control three or more other lands, however, it enters the battlefield tapped.
If one of these lands enters the battlefield at the same time as one or more other lands, it doesn't take those lands into consideration when determining how many other lands you control.