Is Rune Snag legal in Standard, Modern, and Commander?

Rune Snag is legal in: Modern, Legacy, Vintage, Commander, Pauper.

What type of card is Rune Snag?

Rune Snag is an Instant. Its oracle text reads: "Counter target spell unless its controller pays {2} plus an additional {2} for each card named Rune Snag in each graveyard. *"Concentration is key. Without it, a mage conjures nothing but a splitting headache." —Zur the Enchanter*"