Sets only ever leave Standard once per year: in the fall, on the day the first set of the new block becomes legal. That set enters Standard, and the entirety of the oldest Standard block (this year that will be Innistrad block) rotates out, along with the older core set (Magic 2013).
For the rest of the year, nothing leaves Standard, and new sets are added as they are released.
Okay, so on release, Magic 2014 will NOT be playable in Standard until the first new Block set in the fall?
Also, Return to Ravnica Block will still be playable?
From what I understand, the current legal sets are
Core:
Magic 2013
Block 1:
Innistrad
Dark Ascension
Avacyn Restored
Block 2:
Return to Ravnica
Gatecrash
Dragon's Maze
What happens when Magic 2014 is released in July? On release day does that mean that Magic 2014 is the new core set that replaces Magic 2013 on that day or is it not playable until the first new Block Set starts in the Fall?
Also, when the first new Block set is released in the Fall, will "Return to Ravnica" Block be considered "Block 1" and still be playable for Standard until a second Block set is released? Or does "Return to Ravnica" Block fall off with "Innistrad" Block?
Okay, so on release, Magic 2014 will NOT be playable in Standard until the first new Block set in the fall?
Also, Return to Ravnica Block will still be playable?
Core:
Magic 2013
Block 1:
Innistrad
Dark Ascension
Avacyn Restored
Block 2:
Return to Ravnica
Gatecrash
Dragon's Maze
What happens when Magic 2014 is released in July? On release day does that mean that Magic 2014 is the new core set that replaces Magic 2013 on that day or is it not playable until the first new Block Set starts in the Fall?
Also, when the first new Block set is released in the Fall, will "Return to Ravnica" Block be considered "Block 1" and still be playable for Standard until a second Block set is released? Or does "Return to Ravnica" Block fall off with "Innistrad" Block?