Buster Sword
Artifact — Equipment
Equipped creature gets +3/+2.
Whenever equipped creature deals combat damage to a player, draw a card, then you may cast a spell from your hand with mana value less than or equal to that damage without paying its mana cost.
Equip 
Commander bracket
Derived from card traits, not a ruling — bracket rules turn on how a deck intends to use a card. Bracket rules
EDHREC
Combos
Not part of any combo on Commander Spellbook.
Format legality
Rulings
- 2025-06-06
If a spell you cast has
in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost. - 2025-06-06
If you cast a spell "without paying its mana cost," you can't choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, those must be paid to cast the spell.
- 2025-06-06
You choose whether to cast a spell from among the cards in your hand as Buster Sword's middle ability resolves. You can't wait to cast one later in the turn. Timing restrictions based on the card's types are ignored.