When your opponent casts a Snapcaster Mage to give something flashback, you get a window of opportunity to do something before that spell can be flashed back. The targeted spell doesn’t immediately have flashback as soon as the Snapcaster hits the field.
Once the Snapcaster resolves, its triggered ability goes on the stack and the controller chooses a target. This is where some players don’t realize the targeted spell doesn’t have flashback yet. That ability won’t resolve until both players pass priority, which means you have a chance to respond with a spell or ability before that player will be able to cast the spell from the graveyard.
For example, you cast Inferno Titan, and your opponent responds with Snapcaster Mage, targeting the Mana Leak in his graveyard. You respond with Surgical Extraction, exiling Mana Leak before it gains flashback. The Snapcaster’s ability is then countered because it no longer has a legal target, and your Inferno Titan can safely resolve (and can even kill the Snapcaster that just entered!).
Today’s Rules Tip written by
Josh Stansfield, Level 2 judge from Orange, CA