This unit overview will give a brief explanation of the various Zerg units in Starcraft 2 based on what tiers they are in.
Tier 1
- Drones – Drones are the mining and gas harvesting unit of the Zerg, along with your building creators. You should make 2-3 Drones per mineral patch. To select idle Drones, press F1. If your enemy comes into your base and attacks your Drone Mineral Line, make sure to immediately select all of your Drones and attack the enemy units. A lot of players freeze up and don’t do anything when their Drones get attacked, or try to run their Drones away, but it is better to attack with them.
- Queens – Queens are decent at base defense, and are needed for Inject Larva and Spawn Creep Tumor to expand creep across the map. They are good at fending off small attacks from ground units and air unit rushes from Protoss Void Rays and Terran Banshees and Vikings.
- Zerglings – Zerglings are a great harassment unit, and a good meatshield unit. They work well as a good addition to any Zerg build. The first combat units you build should be 6 Zerglings, and you should send them to scout your opponents base and harass their mineral line. If you mass Roaches/Hydralisk, you should always also build 6 to 12 Zerglings to absord the first volley of fire in each battle.
- Roaches – Roaches are a very strong unit for the Zerg and do well against all ground units. They especially work well with Hydralisks as they act as a meat shield for Hydras with their shorter attack range. They are also good counters to Terran Thors, as you can burrow and surround the Thors, then unburrow and take them down.
- Banelings – Banelings are not very cost effective and are not used very often in pro games. Banelings are best used in Zerg vs Zerg games to rush alongside Zerglings. In mid to late games their effectiveness is greatly reduce due to focus fire by ranged units. The best way to use Banelings is to engage the enemy, then while your enemy is focused on fighting your combat units send in the Banelings so they can explode before your enemy has a chance to react and focus fire them.
Tier 2
- Hydralisks – They are great anti-air units with their long attack rage, and work well when paired with Brood Lords and Mutalisks to give them anti-air support. They work well with Zerglings and Roaches. Great against Marines, Marauders, Zealots, Stalkers, and just about every unit in the game when masses and microed properly. They are weak against Colossus, but you should either focus fire the Colossus or get Corruptors or Mutalisks to counter them.
- Mutalisks – Mutalisks are great for harassing your opponents base and expansions due to their very fast movement speed, but they are not a very good unit to use to mass to fight against other combat units as Mutalisks are countered by many different commonly massed units such as Stalkers, Thors, Marines, Sentries, Hyralisks, and Vikings. You should pair them with Hydralisks as they work well together.
- Infestors – Infestors are an incredibly powerful Zerg unit, and do very well as support for mass Roaches and Hydralisks. With their Neural Parasite ability they can capture Thors and Ultralisk and turn them against your opponent. With Fungal Growth they can be used as effective crowd control units against mass Marines/Marauders, Zealots/Stalkers/Immortals and Zerglings/Roaches. They can also spawn Infested Terran, but this is the least useful of their three abilities.
- Corruptors – Corruptors can only attack air units. Corruptors are the perfect counter to Protoss Colossus, but are susceptible to anti-air ground units such as Stalkers, Marines, and Hydralisks.
- Overseer – Detectors of cloaked units. Overseers are a must if you are facing Protoss Dark Templar, Terran Ghosts, or Terran Banshees.
Tier 3
- Brood Lords – Brood Lords are a very strong anti-ground unit, comparable to. They should be paired with a strong Anti-Air unit such as Hydralisks or Corruptors to protect them from Vikings, Stalkers, and Phoenixes.
- Ultralisks – Ultralisks are the zerg "tank". They have an enormous amount of hit points and armor that makes them great at absorbing hits. They are also very fast and do great damage (in a cleave) to armored units such as Stalkers and Siege tanks. Ultralisks are the prime choice for late-game anti-armor attacks.
This video will give you an depth overview of all the Zerg units within Starcraft 2.