The powerful Zerg are one of the best at making unit transitions and playing macro heavy games

Hydralisks: There are a number of strategies for getting to Hydralisks as fast as possible, with one possible setup dubbed the macro-intensive "IdrA" build, where the player gets a spawning pool at 15 drones, an expansion hatchery at 16 drones, produces a few defensive Zerglings (and perhaps a Spine Crawler if he or she expects early aggression), and then they play defensively, getting to those powerful Hydralisks and expanding even more if their enemy doesn't play aggressively. The reason why Hydralisks are currently so powerful really comes from the fact that they attack fast, they deal fairly decent neutral damage to all units, they're quite speedy on creep, they're fairly cheap to create without being vespene gas heavy, and they build quickly.

Prior to this, many Zerg players typically liked to also get the powerful Roach unit mixed in with their Hydras, or even just go Roach / Zerg in early games before transitioning to the Hydralisk later on, but Blizzard stepped in and made the Roach cost 2 supply instead of 1, thereby making it more difficult to generate massive groups of Roaches in early games. In response to this, some Zerg players have decided to simply skip that early aggressive Roach play, and instead they just go for Hydralisks, forcing a macro management heavy game.

Mutalisk Harass: Mutalisks are the super-fast air units of the Zerg, and if players don't see it coming, a few Mutalisks can effectively destroy a player economy in the blink of an eye. These days, unfortunately, players are getting more tools to counter the powerful Mutalisk, with Terran Thors able to explode large masses of Mutas, seemingly at will, and Protoss Stalkers and Phoenixes both having the ability to out-maneuver the Mutalisk, the former being a huge nuisance with the Blink ability, and the latter gaining the invaluable ability to attack while moving while also having a damage bonus versus light units (which the Mutalisk is). You can also use the Mutalisk as a heavy harassment unit - scouting the map and hitting at random times, thereby forcing your opponent to play much more defensively.

The "Baneling Bust:" Most often used early against players who like to block their entrances with buildings or units. It's a bit riskier to use it against Protoss players, who can use their Sentry Force Fields to deny access to the powerful Baneling, but, because the Baneling can be somewhat surprising, these little bombs have taken many enemies by surprise. Simply make your way to Banelings as fast as possible, all the while producing little Zerglings, and when the time is right, lead with your Zerglings (to absorb the hits) while rolling your Banelings in to blow up buildings, or (if you're lucky) your opponent's entire mineral line. Interestingly, the Baneling Bust is mostly seen on maps with wide ramps, like Scrap Station, where Banelings can roll up that short, wide ramp and melt an opponent's defense wall like it was butter.

Spine Crawler Rush!: This is really a bit of an odd strategy, and it only works against an opposing Zerg player, but it's quite funny if you pull it off properly. The Spine Crawler rush is essentially where the Zerg player gets an early, early Spawning Pool, builds a few Zerglings and then rushes his opponent's base with his Zerglings and two drones. Make sure that you have at least 200 resources once you attack, and then rush your Zerglings and Drones in. The moment you get to your opponent's base, set your drones to become two Spine Crawlers on your opponent's creep, and use your Zerglings to defend the Spine Crawlers as they build. If you were fast enough, your opponent shouldn't be able to get both of your building Spine Crawlers down in time (especially if you use your Zerglings purely to defend), and once your Spine Crawlers build, they'll destroy anything and everything nearby.

And these are just a few Zerg strategies that players can employ when first learning to play the Zerg. Remember, these are simple, basic strategies that I've run into in all levels of play in Starcraft 2. Once you decide to really master this race, you should learn to adapt these strategies to your own style of play. Roaches are still a powerful choice for the Zerg race, and many players overlook the awesome power of a burrowed Roach rush, so also realize that these strategies don't even begin to cover all of the possibilities available to the Zerg. Learn to experiment! Tomorrow we'll be covering the Terran.

You can read our overview of the Protoss here!