Void

{3}{B}{R} · Sorcery

Choose a number. Destroy all artifacts and creatures with mana value equal to that number. Then target player reveals their hand and discards all nonland cards with mana value equal to the number.

Motor: se resuelve a mano

Rulings (2)

The target player is chosen as you announce Void, but the number isn’t chosen until it’s resolving. No player may choose to take actions between you choosing a number and the rest of Void’s effects.
Wizards of the Coast · 2016-06-08
You can choose 0. Artifact lands and most tokens have mana values of 0, for example.
Wizards of the Coast · 2016-06-08