Is Defense of the Heart legal in Standard, Modern, and Commander?

Defense of the Heart is legal in: Legacy, Vintage, Commander, Historic.

Defense of the Heart

Q: What type of card is Defense of the Heart?

Defense of the Heart is an Enchantment. Its oracle text reads: "At the beginning of your upkeep, if an opponent controls three or more creatures, sacrifice this enchantment, search your library for up to two creature cards, put those cards onto the battlefield, then shuffle."

Enchantment

At the beginning of your upkeep, if an opponent controls three or more creatures, sacrifice this enchantment, search your library for up to two creature cards, put those cards onto the battlefield, then shuffle.

Set Urza's Legacy

Rarity Rare

Mana Value 4

Artist Rebecca Guay

Collector # 100

Scryfall Gatherer