While Magic's history stretches back 30 years, the lore of Dominaria itself is much longer. Returning to a pivotal story of Dominaria's—and Magic's—history, what started as a feud between Urza and Mishra erupted into an all-out war that set into motion the future of the plane and Multiverse itself.

The Brothers' War Set Booster Box contains 30 Set Booster packs, which each include 12 Magic cards, 1 Art Card, and 1 token, ad card, or special card from Magic's history (a card from "The List"). Each pack contains a combination of 1–5 card(s) of rarity Rare or higher and 3–7 Uncommon, 3–6 Common, and 1 Land cards. Traditional Foil Land replaces basic land in 20% of Set Boosters. Foil-Stamped Signature Art Card replaces Art Card in 10% of Set Boosters.