http://www.wizards.com/Magic/Magazine/Article.aspx?x=mtg/daily/arcana/1161

The Simic Combine has a new agenda for a new era: reclaim the recently uncovered seas and then restore the Ravnican wilderness. The "Thrive and Thrash" deck opens the game with a focused effort to quickly develop its available mana. Once you've assembled massive amounts of mana generation, follow through with gigantic monsters and game-winning spells. Your opponents will be helpless against the sheer power of your late-game plays.

While your opponent hopefully slogs along at one more mana a turn, your deck provides you some powerful tools to get ahead. Arbor Elf, Farseek, and Verdant Haven can each provide one additional mana. And if Verdant Haven is enchanting a Forest, your Arbor Elves get that much better. You'll be casting your more expensive creatures while your opponents are stuck in the mud.

Remember that your deck's strength lies in its late game, so don't panic if you take some damage early. In time, you'll have excellent measures for keeping the battlefield under control. Thragtusk and Acidic Slime provide spell-like effects when they enter the battlefield and then play defense, taking away your opponent's advantageous attack plans. Ground Assault is a cheap removal spell that gets more powerful the more lands you have. If you consistently develop your mana, you won't stay on the defensive for very long.

Your deck is primed to make sure your last few turns are overwhelming. The massive Gruul Ragebeast fights another creature as soon as it hits the battlefield. On top of that, this Beast lets all your creatures fight when they enter the battlefield. It's an onslaught of blows your opponent will be hard-pressed to withstand. Sphinx of Uthuun is a 5/6 flier that refills your hand, ensuring that the hits keep coming. Deadeye Navigator's strength isn't as obvious, but it can be dominant once you master its nuances. If it's paired, you can blink the Navigator itself or the creature it's paired with for only {1}{U}. This lets you dodge incoming removal spells, lets you reuse any "enter the battlefield" abilities, or lets the Navigator pair with a different creature any time you want. That's enormous flexibility for a low, low price.

Your sideboard is filled with specialized defensive options. If your opponent storms out of the gate with cheap, aggressive creatures, bring in Flames of the Firebrand to dismantle his or her early assault. Dissipate and Negate are key against slower decks that don't apply early pressure but instead rely on a few powerful spells to win the game. Naturalize is a great choice against powerful artifacts and enchantments.

You can improve the "Thrive and Thrash" in a few different ways. The splash of red cards is powerful but vulnerable if you can't reliably find red mana. Shore this up with the "dual lands" Steam Vents and Stomping Grounds. These powerful lands give you greater mana diversity and work very well with Farseek. Need some more defense? Bonfire of the Damned from Avacyn Restored is a sweeping removal spell that gets more powerful the more mana you have. Finally, check out new options for your late game, including Craterhoof Behemoth from Avacyn Restored, Sphinx's Revelation from Return to Ravnica, or Omniscience from the Magic 2013 core set.