Notes and Rules Information for Boom // Bust:

• Only the English version of a Magic card receives Oracle updates and errata. View this card in English. (Scryfall note)
• If one of Boom’s targets becomes an illegal target, the other is still destroyed. (2021-03-19)
• To cast a split card, you choose one half to cast. There’s no way to cast both halves of the split cards featured in this set. (2021-03-19)
• All split cards have two card faces on a single card, and you put a split card onto the stack as only the half you’re casting. The characteristics of the half of the card you didn’t cast are ignored while the spell is on the stack. (2021-03-19)
• Each split card is a single card. For example, if you discard a split card, you’ve discarded one card, not two. If an effect counts the number of instant and sorcery cards in your graveyard, Boom // Bust counts once, not twice. (2021-03-19)

• Each split card has two names. If an effect instructs you to choose a card name, you may choose one of those names, but not both. (2021-03-19)
• While not on the stack, the characteristics of a split card are the combination of its two halves. For example, Boom // Bust has a mana value of 8. This means that if an effect allows you to search for a card with mana value 4 or less, you can’t find Boom // Bust. (2021-03-19)
• If an effect allows you to cast a spell with certain characteristics, consider only the half you’re casting. For example, if an effect allows you to cast a spell with mana value 4 or less from your hand, you can cast Boom but not Bust. (2021-03-19)
• If you copy a spell that’s half of a split card, the copy copies that same half. For example, if you copy Boom, the copy is also Boom, not Bust. (2021-03-19)