Brainwash

{W} · Enchantment — Aura

Enchant creature Enchanted creature can't attack unless its controller pays {3}.

Motor: se resuelve a mano

Rulings (3)

If there are multiple combat phases during the turn, the attack cost must be paid each time if you want to attack with the creature.
Wizards of the Coast · 2004-10-04
Paying this cost is not an instant or any other kind of ability, it is an additional cost on the declaration of the attacker.
Wizards of the Coast · 2004-10-04
This ability is paid for during the declare attackers step of the combat phase.
Wizards of the Coast · 2004-10-04