Is Koskun Falls legal in Standard, Modern, and Commander?

Koskun Falls is legal in: Legacy, Vintage, Commander.

Koskun Falls

Q: What type of card is Koskun Falls?

Koskun Falls is a World Enchantment. Its oracle text reads: "At the beginning of your upkeep, sacrifice Koskun Falls unless you tap an untapped creature you control.Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you."

World Enchantment

At the beginning of your upkeep, sacrifice Koskun Falls unless you tap an untapped creature you control.<br>Creatures can't attack you unless their controller pays for each creature they control that's attacking you.

Set Homelands

Rarity Rare

Artist Rob Alexander