Is Counterbalance legal in Standard, Modern, and Commander?

Counterbalance is legal in: Modern, Legacy, Vintage, Commander.

Counterbalance

Q: What type of card is Counterbalance?

Counterbalance is an Enchantment. Its oracle text reads: "Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card."

Enchantment

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card.

Set Coldsnap

Rarity Uncommon

Mana Value 2

Artist John Zeleznik

Collector # 31

Scryfall