Artifact, 2 (2) Imprint - When Isochron Scepter comes into play, you may remove an instant card with converted mana cost 2 or less in your hand from the game. (The removed card is imprinted on this artifact.) {2}, {T}: You may copy the imprinted instant card. If you do, you may play the copy without paying its mana cost.1
Illus. Mark Harrison
10/4/2004: If the imprinted card leaves the removed-from-game zone while the ability to make a copy is on the stack, then no copy will be made.
10/4/2004: If this card leaves play while the ability to make a copy is on the stack, the ability will still make a copy using last-known-information rule.
12/1/2004: Isochron Scepter's second ability creates a copy of the imprinted card in the removed-from-game zone (that's where the imprinted Instant card is), then allows you to play it without paying its mana cost.
12/1/2004: You play the copy while this ability is resolving, and still on the stack. Normally, you're not allowed to play spells and abilities at this time. Isochron Scepter's ability provides an exception.
12/1/2004: You don't pay the spell's mana cost. If the spell has X in its mana cost, X is 0. You do pay any additional costs for that spell. You can't use any alternative costs.
12/1/2004: If the copied card is a split card, you may choose to play either side of the split card, but not both. The split cards Fire/Ice, Illusion/Reality, Night/Day, Stand/Deliver, and Wax/Wane all have at least one side with converted mana cost 2 or less.)
12/1/2004: You can't play the copy if an effect prevents you from playing Instants or from playing that particular Instant.
12/1/2004: You can't play the copy unless all of its targets can be chosen.
12/1/2004: If you don't want to play the copy, you can choose not to; the copy ceases to exist the next time state-based effects are checked.
3/1/2005: The creation of the copy and then the playing of the copy are both optional.
Mirrodin
(Uncommon)