14 hatch (ZvT)
This build is currently regarded as the standard opening in the current way ZvT is played, and is prevalent across all leagues. It is an economic macro-focused build focused on securing an early expansion for Zerg, thus helping speed up both Larva production and therefore unit/drone production as well. Scouting with a drone at 9 food is absolutely critical.
The goal of this opening is to secure an early expansion for Zerg, therefore providing more opportunities for a macro-oriented play by leading to various opportunities in the midgame. By securing a strong economy early on, this build has numerous mid-game transitions such as 2 hatch Baneling bust, 2 hatch econ muta, 3 hatch muta, and 2 hatch fast Infestor.
Pros to this build include a macro-oriented play and a very strong economy into the midgame. Cons include being weak to early all-in builds and fast aggression.
Basic Build Order
Eventually as soon as you get 100 gas you will want to get ling speed. However, when you get ling speed may depend, as you will see later. It is preferable to scout at 9 on long-distance maps as Terran can wall-off at the bottom of their ramp with 1 Supply Depot and 1 rax to deny scouting.
Scouting is crucial for this build to work, due to the Terran wall off meaning they are unable to be scouted until Lair tech. First of all be sure to send your first/second Overlord nearby their base, able so you can sacrifice it to gain some crucial scouting information. Also when scouting with your initial drone you need to find out some crucial things:
1.Did your opponent get a gas? If so, feel free to drone up some more as well as gas steal with the scouting drone to prevent any fast Banshees. Another option to dealing with Banshees is to simply get 3-4 Queens. Most likely the opponent will be going some sort of Factory play or 3 rax timing push, both of which will take some time.
2.Did your opponent get two Barracks? If so, watch out! Most likely your opponent is going to be going either a fast Command Center, a two rax Marine-SCV all-in, or a 4 rax SCV all-in. This is where your Overlord is very crucial. You have to sac it to find which of these your opponet is going.
If you are unable to sacrifice an Overlord/get the required info the next best thing is to constantly poke in to see if your opponent is making Marines out of his two Barracks. Whether your opponent is making Marines constantly (probably all-in) or not (probably fast CC) will determine what you need to do.
Once you are saturated at both bases, you can than transition into two styles of play. One is the "Kyrix Style agression", popularized by the GSL Zerg Kyrix. In this type, you saturate both bases you have (at least 12, preferably 16 drones at each base) and then start massing lings and Banelings. Oftentimes you go for a delayed Baneling bust, and try to keep the Terran inside and contained.
However, the much more common way of playing now is the traditional muta-ling-Baneling, in which you tech up to Lair and get a Spire. By forcing him to get Marines, you also can wipe out those Marines with Banelings! In this strat you can also take a semi quick third (around the time when your Lair is finished/starting a Spire).
You will need to adapt very well in order to do well with this strategy.-based on what scouting information you have. There are a number of ways this can work out:
Fast Command Center If you scout the Terran going for a somewhat fast Command Center off of two rax, then you will need to drone up more to be able to deal with the Terran economy. However your opponent will be preparing for a semi large Marine push (not SCVs most likely) of 5-6 Marines.-based on how long he waits to push out the number of Marines will change. Be sure to have at least 15 Zerglings, enough to easily surround the Marines and be able to lay on some counter aggression. But your focus should be on droning up and eventual transition into Lair tech.
Two rax If you know for a fact your opponent is staying on two rax (and be sure to check for proxy raxes as that is very common), then most likely he is going into a Marine-SCV all-in. Stay on Zergling tech, and pull your drones towards your natural so they can easily help fight at a moment's notice. Once your opponent attacks, pull all drones off gas (unless you need them for Banelings. And unless the Baneling Nest has already started you should pull drones off gas.) Once your opponent attacks be sure to use the Zerglings to surround and kill the Marines, not the SCVs. The Marines are the ones dealing the damage. Once they are dead, the SCVs are there for easy pickings. Once that push is held off drone up some more and prepare for most likely another all-in, but also be prepared to just macro up if you see him teching.
4 rax If you scout 4 rax, as soon as you get 100 gas get Zergling speed. Then as soon as you get 50 more gas get a Baneling Nest. That will be crucial for fending off the Marine SCV all-in that is to come. You can afford to make around 2-3 drones, but do not think for a second you can afford to make more, and even that is sometimes risky. As soon as you get 3-4 Banelings you should be safe, but have at least 10 more Zerglings just to make sure your opponent cannot micro their marines to negate your Banelings. Be prepared to micro your Banelings for maximum effect, and not just waste them on a single SCV.
Maps with long rush distance are especially good for this build, as they negate the power that Terran all-ins can offer.
Maps with a short rush distance are bad for this build order. Maps like Steppes of War are especially dangerous for this build, as 4 rax Marine/SCV all-ins are very powerful and hard to stop due to lack of defender's advantage.