Zerg vs terran (ZvT) has been considered one of the most exciting matchups in StarCraft since its inception. Given the high mobility of units from both races these games tend to be high-octane slugfests with action occurring all over the map simultaneously.
During the early game, your main priorities in ZvT are to get your economy up and running, produce some extra queens and start spreading creep and maintain a lead in expansions. You will also want to start climbing the tech tree up so that you can produce higher quality units and get the upgrades which are vital to remaining competitive throughout a long game.
The strongest and most popular opening for zergs in this matchup is a fast expansion. You start off with a couple of drones, then an overlord, then a few more drones and finally throw down an expansion at your natural base. You should then morph a spawning pool and an extractor so that you can start your queen production, build a few defensive lings to hold off the reaper and upgrade zergling speed. You can also choose to do this build with the spawning pool and extractor first but without sacrificing economy. Dark uses this style to great effect and you are not really setting yourself behind because the earlier queen production makes up for the later second hatchery. Going with a pool first expansion can allow you to sneak some lings across the map early on and delay your opponent’s fast expansion command center.
There are a few other early game options, such as throwing down an offensive hatchery and trying to end the game with a ravager and queen push off what is essentially one base or trying to do some damage with a twelve pool and followup baneling bust, but these options are less powerful and quite risky. Because you start off with so many workers in Legacy of the Void, extremely aggressive builds in the early game are much less effective than they were in previous expansions.
Once your spawning pool morphs you are going to want to start queen production right away at both hatcheries. You’ll want to be scouting with your overlords at this point, setting them up in strategic locations around the map to spy on what your opponent is building and to keep an eye on his troop movements, but be careful not to lose them and become supply blocked.
Usually, with zerg vs terran you want to stay one base ahead of your opponent. You also don’t want to be two bases ahead of your opponent because if he is massing up for a big attack those three hundred minerals might be more wisely invested in units to fight him off. Getting your third base up and running is an important early game priority if your opponent chose to go with a fast expand, which he will in the vast majority of cases.
Zerg is very much a reactive race, so your next step is going to be to scout what your opponent is doing in order to counter it. Terrans have a lot of different harass and attack options in the early to midgame so it is important to stay vigilant in your scouting lest you be caught unprepared and suffer catastrophic losses to your drone lines and getting a speed upgrade for your overlords early on is strongly recommended. Not only can the speed upgrade allow you to fly over the terran base and see what they are building, but it will also save your overlords if they get chased around the map by a lone viking.
Some popular terran openings are hellion harass, hellbat pushes, double drop, window mine drop and liberator harass.
Hellion harass is very strong early on because these highly mobile units can be rapidly pumped out two at a time from a factory that has a reactor core add-on. While hellions can roast a phenomenal number of drones if they sneak past your units, this attack can be quite easily foiled with just queens and zerglings. Make sure to move all of your queens to your front lines and jam up the hellions with your zerglings to prevent them from executing the hit and run micro technique. If the terran player does manage to get through your defenses, don’t panic. Hellions have modest splash damage, so you are going to want to spread out your drones in order to minimize it.
Once the terran player has built an armory, hellions can be morphed into hellbats. Hellbats are a hard counter to zerglings, so you are going to want either a lot of queens or some banelings to deal with this threat. If the attack happens before your baneling nest is finished try to engage with your queens first, only bringing your zerglings in at the last moment when the Hellbats are already low on health. Make sure to use transfuse to keep low hitpoint queens alive during the queen vs hellbat battle. Roaches are also a pretty good counter to hellbats.
If you suspect your opponent will be going for a drop, then you want to spread your army out across all of your bases so that you will be able to fend off any attack. Queens can usually deal with liberator harass on their own but spores are an excellent hard counter to this as well because liberators cannot target buildings.
As you approach the middle game maintaining a strong map presence becomes very important. Hopefully by this time you will have spread creep to at least the center of the map, giving your units more mobility as well as allowing you to see what is going on everywhere. Terran players don’t like to fight on open ground, they prefer choke points where units get bottled up, so it is important to keep your army out in the middle and try to engage them when they are moving toward your base. Once a terran player gets setup in a position they can be difficult to unlodge. Usually your opponent will go for a biological composition of marines, marauders, medivacs and widow mines or tanks but mech is also an increasingly popular choice.
The core Zerg answer to bio in the present meta is hydra / ling / bane. The banes deal with the legions of attacking marines while the hydras provide support and the lings are necessary because otherwise you would have a hopeless mineral glut. You will want to engage on creep whenever possible and try to micro your units for maximum effectiveness. Banelings are great against marines but fairly lousy against Marauders, so your opponent will generally try to let his marauders soak up the baneling hits. Terrans also love to set up mine fields and try to lure your gas intensive units into them, so try not to get baited.
Another common terran middle game tactic is to attack or drop in two or three places at the same time. The ability to attack and defend in multiple locations simultaneously is the hallmark of an expert StarCraft player and dealing with these engagements can be extremely frustrating. Try not to just F2 all of your units to go deal with a drop, instead break off just enough units to handle it and keep the rest of your army in position in the middle of the map. If you stay on top of your map vision by continuing to spread creep and keeping overlords spread out across the map it will be difficult for the Terran player to truly catch you unaware.
If you want to win in this matchup you need to be careful about picking good fights and patiently waiting for a winning engagement. As a zerg, you are going to want to surround your opponent and hit from multiple angles at the same time. Your opponent is going to want to attack and push in, so you can use this against him by positioning your forces so that they will cut off any potential retreat. Make sure that you continue to macro during any battles so that you will have the forces available to win the next fight as well.
One great tactic that can find a lot of success during the midgame is a zergling or baneling run by. Zergling runbys in particular have very little risk for a large potential reward because four hundred minerals have very little utility at this point in the game. The goal of a run by is that your units sneak around the side of the map and hit one of your opponents undefended peripheral bases or even their natural expansion and cause havoc in the mineral line. Banelings with centrifugal hooks upgraded are great for this because of their massive splash damage that can quickly wipe out an entire mineral line of workers. Another related tactic is baneling drops, which are pretty self-explanatory and easy to execute. You just morph a drop overlord, fill it with four banelings and head towards the nearest enemy worker line. For bonus points, you can drop in two mineral lines simultaneously and/or distract your opponent with troop movements in some other part of the map.
Infestors can be very valuable in the mid game and spellcasters in general have more utility when both sides have massive armies, especially when you are talking about spells that do area of effect damage like fungal growth. Roach ravager used to be a popular style and combining the ravager’s corrosive bile ability with the fungals is a nice tactic but you don’t see a ton of roach play from top Koreans anymore unless they are going for an early roach ravager all in. Roaches just don’t have a lot of utility as the game goes on. That being said during the early middle game if you upgrade burrow and/or tunneling claws you can do some very nice harass tactics with roaches, killing workers and forcing your opponent to burn a lot of scans.
If your opponent does go mech then swarm hosts and hydralisks are generally the preferred answer, although there are a lot of different flavors of mech that your opponent can choose from. Swarm Hosts are great because you get a lot of utility out of them the longer they are in play and once they reach a critical mass they can do a lot of damage and interrupt mining by sending in the waves across natural barriers in the map. Because swarm hosts are useless during their cooldown period the hydralisks can protect them when they are trying to get near the enemy base to launch their locusts. Your hydras can also engage with the locusts, adding a significantly larger amount of damage per second (DPS) to the attack and then running away once the locusts are dead or expired.
The three main components of Zerg late game tech are ultras, broodlords and vipers. Ultras in particular are very powerful and usually you will want to throw down an ultra den as soon as the hive finishes. Without chitinous plating these units aren’t really that great, but once they are fully upgraded ultras can tank for days and can really just mow through even a massive number of marines. A lot of your middle game strategy as Zerg is going to be jockeying for position so that you have the time and the money to tech up to Ultras and then just dominate the map and force the Terran to huddle defensively in his base. For their part, Terrans do have some answers to ultra tech, specifically range Liberators and Ghosts, so it is not like Ultras are just gg every time but usually if you can get out upgraded ultras without being hopelessly behind you will be in a pretty good position. You can combo queens and ultras to great effect because transfuse can keep these behemoths alive almost indefinitely, and the Zerg player’s queens are going to have a lot of energy during the late game.
Vipers are also incredibly cost efficient if you use them effectively. You can abduct liberators or seige Tanks into your army as well as casting blinding cloud on clumped up tanks to render them momentarily ineffective. Parasitic bomb can be used on clumped up vikings as well.
Broodlords are also a strong late game tech choice. One of the nice things about zerg is that if you build up a bank you have the ability to make a massive tech switch after a big late-game engagement that wipes out a lot of your army, and it is very easy to re-max as well because you can accumulate a lot of extra larva if you keep up your injects. Three-three zerglings with the adrenal upgrade also become very cost efficient during the late game especially for harassment purposes