Is Heroism legal in Standard, Modern, and Commander?

Heroism is legal in: Legacy, Vintage, Commander.

Heroism

Q: What type of card is Heroism?

Heroism is an Enchantment. Its oracle text reads: "Sacrifice a white creature: For each attacking red creature, prevent all combat damage that would be dealt by that creature this turn unless its controller pays {2}{R}."

Enchantment

Sacrifice a white creature: For each attacking red creature, prevent all combat damage that would be dealt by that creature this turn unless its controller pays .