Koskun Falls

Card Name

Koskun Falls

Mana Cost

2

Type

World Enchantment

Rarity

Rare

rules Text

During your upkeep, tap target untapped creature you control or bury Koskun Falls.No creature can attack you unless its controller pays an additional
2
whenever that creature attacks.

Legal Formats

Commander, Legacy, Vintage

Not Legal Formats

Alchemy, Brawl, Explorer, Historic, Modern, Pauper, Pioneer, Standard

Rulings

(2/1/2007)
In the Two-Headed Giant format, you still only have to pay once per creature.
(10/1/2008)
This has the supertype world. When a world permanent enters, any world permanents that were already on the battlefield are put into their owners' graveyards. This is a state-based action called the "world rule." The new world permanent stays on the battlefield. If two world permanents enter at the same time, they're both put into their owners' graveyards.
(2/1/2014)
Unless some effect explicitly says otherwise, a creature that can't attack you can still attack a planeswalker you control.