Invasion common. This card was inspired by the relationship between Llanowar Elves and Birds of Paradise. By adding a drawback (in this case an extra mana in the cost) to green staple Wild Growth, Fertile Ground gained the ability to generate any color of mana rather than just 
Invasion rare. Antiquities was Mark Rosewater’s favorite expansion for years, and his favorite card was Argivian Archaeologist. Since joining the company as a designer he’d been looking for a chance to bring the player favorite back in some fashion, and when he realized that the Weatherlight Saga character Hanna was an engineer the opportunity was too good to pass up.
Ninth Edition rare. This card first appeared in Tempest, but only by chance! Originally that slot was supposed to go to Letter Bomb. However, after the art had been delivered the rules team nixed Letter Bomb because it involved putting a card into the other player’s deck, something that wasn’t acceptable for tournament magic. Booby Trap was designed to fill the slot and still fit the art, and Letter Bomb eventually made it into print in Unhinged.
Ninth Edition rare. Marble Titan was designed for Tempest by Richard Garfield. Originally just one member of an entire race of creatures that had this same ability, none of the other cards made it into the set.
Ice Age rare. The original version of this card caused a lot of confusion because many players assumed it had flying due to the card’s art. Though Blinking Spirit caught a lot of flack for this, Whippoorwill from The Dark was even worse, as it has wings and is even in the act of flying!
Ninth Edition rare. Battle of Wits was part of a five-card alternate win condition cycle along with Test of Endurance, Mortal Combat, Epic Struggle, and Chance Encounter. Occasionally a card makes it into the core set that was part of a cycle, but none of the other cycle members get promoted (see Serra’s Embrace).
