Creature — Human Wizard 2/2, 2UU (4)
Rare
Whenever you cast an instant spell, you may pay {1}. If you do, draw a card.
"I'm pleased this world has learned the moon affects more than the tides."
—Tamiyo, the Moon Sage
Illus. Wesley Burt

5/1/2012: The triggered ability will go on the stack on top of the instant spell and resolve before it.
5/1/2012: The decision to pay {1} is made when the triggered ability resolves. It's not an additional cost of the instant spell.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Standard (Type 2)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern