Starcraft

Overlord
These units serve a number of uses, first and foremost they control your troops, so they are necessary to the Zerg in the same way as supply stations to the Terrans and psi pylons to the Protoss. This means that you can end up with lot of these creatures floating around cluttering up your base. Your first instinct will be to usher them off to a relatively secluded area, trying to clear the air around your base so that you can see more clearly. This is a suicidal instinct, the Overlord is also the Zerg's primary spotter, this means it can see cloaked units, so it is always good to have a few of these patrolling your perimeter whilst keeping a couple in vital areas throughout your base. The final use of the Overlord is as a carrier, these gigantic creatures are capable of carrying Zerg troops in the same way as the Terran dropship. Not enormously quick or well armoured the Overlord can be upgraded quite far, increasing its speed and armour.

Weapon: None
Armour: 0
Armour increase per upgrade: +1 +2 +3

Zergling
The Zergling is the most basic of the Zerg warrior units, fast and cheap these creatures can only really win a battle by the use of overwhelming numbers. A lone Zergling would be hard pressed to come off best in a straight fight with a Terran SCV, but the cheapness of the Zergling (50 crystals for 2) means that the Zergling should never have to attack on its own. A good basis for the army, the Zergling can be employed in huge numbers either as a shock attack force, or as cannon fodder to cover the approach of larger more effective troops.

Never ever charge a group of Zerglings toward a Terran bunker, the speed and power of the marines that generally inhabit these structures means that they can generally destroy Zerglings well before they can even get close to damaging the structure or its occupants. One extremely fine use of the Zergling is as a suicide troop, implaced siege tanks tend to be placed together, so by running a Zergling to the base of a tank you can cause the Terran tanks to destroy one another. Excellent for patrolling base perimeters in vast numbers, the Zergling's speed will carry it across a patrol area quickly giving you ample warning of impending attacks.

The Zergling also makes an ideal ambush unit, all you need to do is develop the burrowing ability at your Hatchery, your Zerglings can then burrow beneath the ground, rendering them immobile but invisible to all but spotter units. Your Zerglings can then leap from their burrows and rip into any troops unfortunate enough o cross their path.

Weapon: Claws
Damage ground: 5
Damage increase per upgrade ground: +1 +2 +3
Armour: 0
Armour increase per upgrade: +1 +2 +3

Hydralisk
An extremely effective unit the Hydralisk is equally deadly against both air and ground targets. With its explosive needle spines the Hydralisk is especially effective against large targets. These creatures are even capable of taking down a target as large as a Protoss Carrier in a remarkably short space of time. The Hydralisk doesn't quite have the range of the Terran marines, it does however have the advantage of damage, its spines inflicting four points of damage than the marine Gauss rifle more than making up for the range difference.

The Hydralisk has got to be the backbone of any Zerg army, their ability to attack both ground and air targets making them invaluable as protectors for ground based units such as the Zergling and Ultralisk. The Hydralisk should be upgraded at the Hydralisk Den as soon as possible to give them both a greater turn of speed and longer spine range, whilst their armour and weapons can be upgraded at the evolution chamber.

The Hydralisk makes an excellent ambush troop, once it has the burrow ability it can hide in large quantities along the perimeter of your camp, giving you vision all around your perimeter, and leaping out to defend your base when it becomes necessary. Hydralisks work best in fairly large groups, 12 is generally considered a nice number to have working together, this gives you the firepower necessary to take down all but the biggest targets, whilst also providing a lot of targets allowing you to maximise your troops regenerative powers. Hydralisks best compliment the powerful Ultralisks and Guardians, both of whom are defenceless against air targets.

Weapon: Needle Spines
Damage air: 10
Damage ground: 10
Damage increase per upgrade air: +1 +2 +3
Damage increase per upgrade ground: +1 +2 +3
Armour: 0
Armour increase per upgrade: +1 +2 +3

Mutalisk
The Mutalisk is an extremely fast unit, with fairly low powered weapons but relatively cheaper n cost than the basic airforce of the other races. The Mutalisk really only works effectively in a large group, its speed and powered being bested easily by the Protoss scout and the Terran Wraith. Best used against ground troops with no ability to attack air borne targets, preferably to harry them, possibly even to kill them. The Mutalisk also has no special abilities other than regeneration and it can take very little damage, so what is the point of it? The Mutalisk is good for precisely two things, metamorphosing into its Guardian aspect and protecting Overlords whilst they are transporting troops.

The Mutalisk's ability to morph into a Guardian is discussed in greater detail below so we shall just skirt around the edges of it here; it is a well-valued ability. Although in this form it has no protection against air attacks, it does develop far more armour, it can take more damage and it can now inflict damage with the best of them.

The Mutalisk's other talent lies in the protection of transporting Overlords. The Overlord is defenceless against all forms of attack, it has no ability to inflict damage so it must, of necessity be defended by an air force. The only unit capable of defending the Overlord wherever it goes is the Mutalisk, since it can fly and shoot both air and ground targets. So although the Mutalisk is far outclasses by the air force of other races in its favour it can regenerate fully at no cost, it is relatively cheap, it can morph into a Guardian (once you have a Greater Spire) and it is the ideal unit to protect Overlords.

Weapon: Acid Spray
Damage air: 9
Damage ground: 9
Damage increase per upgrade air: +1 +2 +3
Damage increase per upgrade ground: +1 +2 +3
Armour: 0
Armour increase per upgrade: +1 +2 +3

Guardian
The Guardian aspect is the more powerful version of the Mutalisk. Able to spit massively damaging balls of acid at ground based enemy targets and with huge amounts of armour the Guardian is without a doubt the Zerg's most powerful unit. The Guardian is like a flying siege weapon, a group of about six of these can take out buildings or units remarkably quickly. Most other creatures fare badly against the Guardian not just because of its massive firepower but because of its astonishing range, able to take out any form of defence from well beyond that defences maximum range, the Guardian is a tragedy for any races defences. The Guardians only weakness is its inability to defend itself from air attacks, this can be devastating if not taken care of, it is always wise to keep one Mutalisk with each Guardian. This way you can defend the Guardian from air attacks with the Mutalisk whilst decimating any ground attacks with the Guardian.

Remember the only weapon with greater range than the Guardian's Acid Balls is the Yamoto gun on the Terran Behemoth, so make good use of this range advantage to wreak havoc upon your enemies ranks.

The bigger the group of Guardians the more effective it becomes, the speed at which they can fire and the range they have can mean a large enough group can destroy everything that comes within range without taking any losses. Combine this awesome weaponry with their regenerative abilities and you have a force that can survive deep in enemy territory systematically destroying everything that comes within their range.

Weapon: Acid Balls
Damage ground: 20
Damage increase per upgrade ground: +2 +4 +6
Armour: 2
Armour increase per upgrade: +1 +2 +3

Scourge
The Scourge is a small extremely fast unit that is designed purely to explode on impact with any flying unit, causing huge amounts of damage. Although quite easy to shoot down because of its lack of armour and inability to take damage, the Scourge's speed can take it into explosive contact with most other airborne units. Scourges make ideal base protecting units, any airborne unit that comes within their visual range becomes the target of their suicidal flight. As with all Zerg units the Scourge is very cheap, although this unit is designed die in the destruction of the enemy the cost is negligible and amount of damage caused is crippling to most other units. Ten of these can destroy a Terran Behemoth Battlecruiser for a fraction of the cost, the only unit these are not particularly effective against is the Protoss Carrier, the scourges tend to be shot down by the ships contained within the Carrier before they have a chance to get close.

Be warned Scourges should never be used to attack enemy bases, the defences will take them down very quickly, especially Terran bunkers and missile turrets.

Ideal for perimeter patrol the scourge will give any airborne unit second thoughts, and enough of them will be able to destroy just about anything getting in too close.

Weapon: Suicide
Damage air: 110
Armour: 0
Armour increase per upgrade: +1 +2 +3

Queen
Able to spawn different parasitic organisms the Queen is a powerful supporting unit. Although lightly armoured and unarmed to inflict damage personally the Queen is an essential part of any complete Zerg force. The Queen has several very powerful abilities this is where her usefulness lies. If a Queen is being attacked she can launch a powerful parasite into its adversary, this will cause the target to explode and create two Broodlings, vicious little creatures that will attack anything none Zerg on sight. This can be a very useful power, wherever the Queen is if she is attacked then she can launch this parasite onto the most powerful of her enemies, turning it into Zerg Broodlings that will then attack the other enemies, giving the Queen time to escape.

The Queen also has a very powerful spying tool in the Parasite ability, this allows her to launch a different parasite at an enemy, this parasite is essentially harmless to the unit, it does however allow you to see everything within the infected units sight. The only way for the enemy unit to rid itself of this parasite is to die, so the unit should itself help to prolong its use to you.

Ensnare is perhaps the least powerful of the Queen's powers, used to slow down units, either those attacking so that their rate of fire is drastically reduced, or those fleeing so that you can catch them swiftly and then pound them whilst they are slowed. An unexpected bonus of Ensnare is that it reveals any cloaked troops in its area of effect. A useful power when facing large quantities of bunched up troops, it can slow them so severely that a relatively small amount of troops will be able to take them down.

The most feared power of the Queen is her power to infest a Terran command centre, the command centre must be damaged to the red, once this has happened the Queen has to saturate it with parasitic bio toxins. This process brings the occupants under the control of the Overmind and mutates the human occupants into biological bombs, Infested Terrans that are discussed further below.

Queens aren't the most powerful of units, they are very fast though and thus able to get in and out very quickly, in this manner you can approach enemy bases, infect an enemy unit with a parasite. Hopefully an infected unit will wander around a bit giving you a good view of the enemy base, it may even give away any incoming attacks.

The Infestation ability can only really be used when you are facing multiple human enemies, in this manner you can take out the smaller of the Terran bases, damage the command centre suitably and then infest it. The Infested Terrans can then be used in the battle against the larger base.

Weapon: None:
Armour: 0
Armour increase per upgrade: +1 +2 +3

Ultralisk
The second most powerful unit available to the Zerg is the Ultralisk, a huge creature easily the size of an armoured vehicle, the Ultralisk inflicts more damage with its Kaiser Blades than even the Guardian with its acid balls. Upgrading the Ultralisk adds nearly 50% to the power of its attacks so do this as early as possible. The Ultralisk is not as slow as you would think, with quite a remarkable turn of speed it is able to run down most unit types quite effectively. Combine their speed with the massive amount of damage they can take and you have about the only ground based troop that can attack siege tanks head on and stand a reasonable chance of success. This makes the Ultralisk invaluable to a large force, if the Hydralisk is the backbone of the Zerg army then the Ultralisks are the knuckles.

It is always wise to use Ultralisks in conjunction with Hydralisk, the ability of the Hydralisk to swiftly reduce air-attacking units to so much wreckage and gore is necessary to protect the air-vulnerable Ultralisk. With the correct support, i.e. Hydralisks and/or Mutalisks the Ultralisk can act like a battering ram, reducing enemy defences to scrap. Ultralisks and Guardians used in conjunction can take care of any base defences, leave the Ultralisks to take care of defences, whilst the Guardian destroys and unit resistance and the Hydralisk and/or Mutalisks keep a weathered eye out for airborne trouble.

Weapon: Kaiser Blades
Damage ground: 20
Damage increase per upgrade ground: +3 +6 +9
Armour: 1
Armour increase per upgrade: +1 +2 +3

Defiler
An evil and sadistic creature the Defiler is perhaps the most sinister of the Zerg, and that is saying quite a bit. Defilers are the Zerg equivalent of biological warfare, unable to defend themselves effectively, the heavily armoured Defiler must rely upon its powers of stealth and its viral stockpile to wreak chaos upon its foes. Able to burrow like most of the other Zerg ground troops, the Defiler is best used in hit and burrow attacks. In these attacks the Defiler can launch one of its viral attacks and then burrow beneath the ground to effectively remove itself from sight where it can regenerate or wait for its power to recharge.

With two distinct powers the Defiler is not amongst the most powerful of the special troops available, it is however the cheapest and is almost as stealthy as the Terran Ghosts.

The Defiler's attacking power is called plague, this will reduce anything to red energy but not below it and will effect anything. This is where the Defiler comes into its own, working by itself the Defiler can get close to the enemy launch its plague and then burrow and watch the action, only to rise when it has the power to attack once more. The other main power of the Defiler is the Dark Swarm, this is a swarm of organisms that live upon the Defiler that can be launched at a certain point. Anything within that point becomes invisible to everything except the Zerg, it functions very much like a large cloaking field, and can be penetrated in the same manner. The Defiler has a last power, it is able to consume its own kind and receive power from the consuming. Put simply the Defiler can eat any other Zerg and will gain extra power for its abilities.

Other than the already mentioned method the Defiler can be used to offer mass covering for troops, enough Defilers can create a massive orange cloud that only the Zerg can see through, this give your troops a massive edge, rendering them all invisible except to spotter units.

Weapon: None
Armour: 1
Armour increase per upgrade: +1 +2 +3

Infested Terran
The Infested Terran has but one use, run him toward the enemy, keeping your troops well clear and watch him destroy whatever he comes into contact with first. The massive explosion given off by a detonating Terran is enough to wipe out a considerable amount of troops once you take the area effect into consideration. The Terrans can also burrow, so you can set up so really devious ambushes that consist of Terrans leaping out of holes and exploding on their targets. The great thing about Infested Terrans is even if they're shot to death they still explode and generally catch something within their area of effect.

Keep these troops well away from your other Zerg as no one is immune to the devastating power of their detonations.

Weapon: Suicide
Damage ground: 500
Armour: 0
Armour increase per upgrade: +1 +2 +3