I have exactly two instants/sorceries in my graveyard, including one Swift Reckoning. Can I use Snapcaster Mage's triggered ability to flashback Swift Reckoning?

I was under the assumption that the legality of casting a spell is checked exactly before actually casting the spell, where, in this case, Spell Mastery still is “active”. But 601.2e talks about checking the legality exactly before determining the cost of the spell, at that point, Swift Reckoning would already be on the stack, making Spell Mastery “inactive”.

Edited Jasper König (Aug. 3, 2015 10:58:02 PM)

You can only flash it back when you could cast a sorcery.

The first thing we do when we announce the spell is move the spell from the zone we're casting it from to the stack (601.2a). Later on, during 601.2e, we check to see if you're able to cast the spell. If you need to cast it as though it had flash, this is the point when it checks to see if you have enough instants and sorceries in your graveyard. At this point, you just have the single instant or sorcery card in your graveyard, so you're not allowed to cast and we rewind to just before you started announcing the spell.

Nathan Long
Wizards.Com Boards NetRep