Teren Strategy

There are basic strategy and Spesifec. I will now explain Spesefic Teren strategy.

Teren V.S Teren

Massive Marines
Against large amounts of Marines and/or Firebats with StimPack build a lot of Bunkers in a close formation throughout your town. Your Bunkers should be built in tight clusters so that each Bunker is able to attack anything attacking the next nearest Bunker. If you place too much space between your Bunkers, the enemy can easily overpower them one by one. When you are attacked, have all your SCVs repair your Bunkers. Repeatedly right click on the Bunkers to keep your SCVs repairing them. If you don't repeatedly right click, the SCVs will stop repairing once they've restored the Bunker to full Hit Points and might run away when attacked. This Bunker repairing method should allow you to survive any early attacks as long as your SCVs mining are protected. Place a few Bunkers around your SCVs mining. Try to have your Marines Stim Packed inside the Bunkers. Unload them, StimPack, then get back inside the Bunker. Once you've defended against a Marine rush, you have several options: try to rush as quickly as possible to Vultures, research Spider Mines and lay down formations of Mines outside your town. You can also choose to bypass the Vultures and head as quickly as possible to Siege Tanks, or do a mixture of both. Vultures are only 25 Minerals more apiece than a Marine. Combined with Spider Mines, and the ability to repair Vultures, enemy Marines/Firebats should be toast. You will need to build 2 or more Factories to quickly build enough Vultures to take the Marine threat because they will most likely have 3-4 Barracks building Marines. Beware: Siege Tanks Ahead!
You should take care to make sure your enemy does not beat you to Siege Tanks. If you don't continue your push up the tech tree, you may find you are quickly attacked by lines of Siege Tanks outside your town, which is often very difficult to stop. Build a few Siege Tanks with Siege Mode for defense, then find out what the enemy is building for. If they are trying for a Siege Tank battle, make sure you have more and use them more effectively. Use Ghosts to Lockdown enemy Tanks, Defensive Matrix your own Tanks to make them last longer against enemy Tanks. Use Wraiths to attack them if the enemy does not go for air targets or doesn't protect them properly with Marines. Control the High Ground
If there is high ground around your town, you must gain control of it, or prevent the enemy from gaining control of it. Something to watch out for is people who will defend their town, and then race as quickly as possible to Siege Tanks and Dropships. If you don't watch out, before you know it they will have unloaded Siege Tanks above your town to fire on it. If you don't have Dropships yourself, and you cannot reach those Tanks, your only choice will be to lift-off your buildings and move out of range. This is really something you should watch out for. If you have Wraiths available and the enemy doesn't defend their Siege Tanks you can use Wraiths to counter the attack. If you have no Wraiths available, but have a Dropship, place Marines in the Dropship and unload them directly on top of the Siege Tanks where they won't be able to return fire. If the enemy supports their Siege Tanks with Marines, you might not be able to fight them. Use Siege Tanks on low ground combined with ComSat to reveal the Tanks on High Ground. If you have more Tanks than the enemy, it might be possible to fire up the hill and destroy the Tanks. Cloaked Wraiths
You shouldn't have too much trouble with cloaked Wraiths if you make use of the ComSat Station and hot keying. If you get attacked by Cloaked Wraiths, move Marines into the area, StimPack them and use ComSat to reveal the cloaked Wraiths. That should quickly get rid of of Wraith threat (if you have enough Marines). You can also use Missile Turrets to spot for cloaked Wraiths but you may find that using ComSat and Marines is easier and faster. Missile Towers are usually most effective if they are spread out across your town to prevent Ghosts from sneaking in, and to chase off Dropships. If you decide to race to cloaked Wraiths, you may find the best use for your Wraiths is to attack mining SCVs and Siege Tanks. To defend against cloaked Wraiths, it's very important to have several Bunkers protecting your SCVs mining. If you do not, the enemy can quickly destroy all your SCVs. You should also try to build one or two Missile Turrets around that area to detect the Wraiths. If the Bunkers are attacked, repair them with your SCVs. If the SCVs are attacked, run them around the Bunkers making the enemy chase them. Pop your Marines out of the Bunker, StimPack, then get back inside. Marine Drop
Protect your resources against the Dropship/Marine drop. Quite often the Terran enemy will load 8 Marines into a Dropship, then drop them off in the middle of your mining SCVs. Combined with StimPack, if you don't have any nearby defenses this will quickly kill all your SCVs and even your Command Center, placing you back into the Stone Age and possibly resulting in a mobility kill. Place a few Missile Turrets around your resources (they're a bargain at only 100 Minerals) and a few Bunkers there to take on any invasions. Siege Tank Spotting
When fighting other Siege Tanks, it's VERY important to have range on them, meaning you can see and fire on them before they fire on you. This means using the ComSat Station or other units such as Dropships to reveal the enemy for your Siege Tanks to fire. Quite often Terran vs Terran games become Tank wars. It is up to you to have MORE Tanks than the enemy and use them more effectively by taking advantage of high ground, and further sight/firing through the use of spotters. Vultures
Remember, Vultures are very good for use against Marines, and Firebats. Spider Mines can be used to fight land troops of all kinds, although large groups of ranged units on Attack-Move may be able to destroy Mines as they activate. If the enemy does this to you, use ComSat to reveal the Mines, and use Siege Tanks or Vultures to clear the Mines. (Vultures will not set the enemy Mines off). A large group of Marines on Attack-Move can also be used as Mine-sweepers, but tight clusters of Mines will still pose a problem. Vultures with the Ion Thrusters upgrade are excellent worker assassins. With their fast speed, they can be used to move past or around defenses and stop the enemy's mining operations. Bunkers will chew up Vultures, though, so this won't work if your opponent's SCVs are protected. Vultures can also easily and quickly scout the map and watch resource spots to prevent the enemy from taking them over. Fighting Lots of Battlecruisers
The enemy may decide to defend their town and, as quickly as they can, build large numbers of Battlecruisers. If they are sloppy in their cloak detection, you can used cloaked Wraiths against them, but skilled players will use a Science Vessel to reveal your cloaked Wraiths or use a ComSat Station to reveal them. Another defense against this, (and probably the best) is to use cloaked Ghosts to Lockdown the Battlecruisers, then use Stim Packed Marines, Wraiths, and/or Goliaths to finish them off. EMP can also be used to knock out the Yamato cannons on enemy Cruisers. You can also use a larger number of Battlecruisers yourself. In this picture, two great Terran fleets of Terran Battlecruisers engage each other. Both have the Yamato cannon, and Yamato blasts from both fleets fire on each other. The Blue Terran fleet attacked the Orange base while it was not defended. Upon finding 5 Starports training Battlecruisers, the Blue fleet destroyed the Control Towers for all 5 Starports and started destroying the Starports as well. The Orange Battlecruiser fleet returned to defend its home. Some Ghosts with Lockdown should have been kept at the base in Bunkers so they could be used to Lockdown these enemy Battlecruisers.


When the smoke cleared, the Blue Fleet won because the Battlecruisers were at full health, were greater in number, and had more upgrades. Some Science Vessels casting EMP and Defensive Matrix, Goliaths and Ghosts casting Lockdown could have shifted the power to the Orange side. With some SCVs repairing, these Battlecruisers will shortly be ready for another battle, also giving the Yamato Cannons time to recharge. Bob Fitch is seen commenting on the battle.

Ghosts and Lockdown
Ghosts and Lockdown can be used against mechanical units . That gives you a lot of targets to Lockdown. Lockdown Wraiths, Siege Tanks in Siege Mode, Dropships, Battlecruisers, or anything that gets in the way. Lockdown is a huge help against most Terran units. I'm sorry sir, but you won't be landing that Dropship full of troops up here.



A cloaked Ghost sneaks toward the enemy base and keeps a Siege Tank from returning fire by Locking it down. A Barracks is constructed near the enemy base to make attacking easier. A Ghost with the Moebius Reactor mana upgrade, and full mana can cloak, then Lockdown one or two units, and still have 25 mana left to remain cloaked. You can cloak, and only Lockdown one unit and use that extra 100 mana saved from not Locking down two units and use that remaining mana to stay cloaked longer. Ghosts do a good job of cutting Terran armadas down to size. In this shot 3 Ghosts and a Marine take on the Terran fleet. Once the units are Locked down you need to attack them. In this shot some Wraiths, Marines, Goliaths are necessary. Unfortunately only a few Ghosts and the Marine are available, so anti-air troops are being rushed to the scene. Lockdown lasts long enough to give them time to get there. Units that come out of the Lockdown are locked down again using more Ghosts.

A Ghost and four Marines defend a town against a Battlecruiser. The Battlecruiser begins to attack. The Ghost pops out of his Bunker and Locks down the enemy Battlecruiser. The Four Marines exit the Bunker and attack the Battlecruiser once it is safe to do so. If more Battlecruisers were used, another Bunker full of Ghosts was available to be used for Lockdowns. SCVs repair Bunkers as they are attacked. The same strategy could be used against Siege Tanks attacking as well as Wraiths.

It is unclear as to what the enemy intended to do with this Science Vessel. They might have wanted to Irradiate some Marines or Ghosts or Reveal and EMP them. Whatever the case, this Science Vessel didn't make it too far as it was locked down and attacked with this multi-unit offense force.





Ghosts can cut down the defense of a Terran town. In this shot a Ghost cloaks, then while hiding in the trees, casts Lockdown on the two Siege Tanks defending the town. Now the town is open for attack. In the cover of trees the enemy might have a hard time noticing the Ghost even if they can see it.




Science Vessel
Use the Science Vessel to spot Ghosts and cloaked Wraiths. Cast Irradiate on tightly packed groups of enemy Barracks units, Marines, Firebats, and Ghosts. Use Defensive Matrix on Siege Tanks, Battlecruisers, and Wraiths to extend their life. If you're desperate, a Matrixed Marine amp'd up on a StimPack can take several enemies with him. EMP groups of Wraiths and Ghosts to hurt their Cloaking. EMP ComSat Stations to stop their Scanner Sweeps. EMP groups of Battlecruisers so they cannot use the Yamato Cannon. Nukes
You may find that nukes are less effective against Terrans because of their ample cloak detection, depending on how well your enemy uses it. If you hear the "Nuclear Launch Detected" warning quickly scan your towns for the red dot, and use the ComSat Station to reveal the Ghost. Hopefully you have some unit nearby that can kill the Ghost once it is revealed and prevent the nuke from landing. Remember, once you spot the dot, move all units away unless they're actively attacking the Ghost, and try to lift-off buildings capable of flight to get them away from the strike zone.

Teren V.s Protoss

Basics
Usually the worry is a large number of Zealots attacking your town early on, or someone going up the tech tree to Reavers. If the enemy simply defends until they get to the units or strategy that they want to do, then things change, but often people pick one of those two offensive strategies. To beat large numbers of Zealots, you need to have 3-4 or more Barracks, and make use of Bunkers. Send in scouting parties early on which should alert you to the possibility that the enemy is trying for Reavers (look for the Robotics Facility, and/or a Cybernetics Core).

Dealing with a large amount of Zealots
If you believe the enemy will send in a large amount of Zealots early, you have two main choices: Entirely Offensive
This is an order that often works. Build a Supply Depot, Barracks, Supply Depot, Barracks, then 1-2 more Barracks and more Supply Depots as necessary all while continuing to build more SCVS. Try to build your base in a very tight formation so Bunkers can cover most of it if or when you decide to build them. Continue making Marines in an even distribution in all 3 or 4 Barracks. Skip mining Gas until a later point to build more Marines, Barracks, and SCVs. An alternate building order is: On SCV #7, build a Barracks.
With SCV #8, build a Supply Depot.
Build a Bunker that will cover your SCVs mining Minerals and all your other buildings. (Building a very tightly packed town is important here)
Fill up your Bunker with 4 Marines then continue on with a normal building order. This will also stop the 6 Zergling Rush if you repair your Bunker while it is being attacked..
Send out your first 2-3 Marines to scout the map and find the enemy if you don't know where he/she is. You may want to go grab an SCV and scout even earlier. After you have discovered what species your opponent is (if you didn't know already) and what they are up to, you can decide how to proceed next. You may find you want to send all your Marines to attack or brace for an attack that they might be sending. It's also vital that you keep checking secondary resource locations to make sure your opponent isn't expanding. You may want to build Bunkers here and there as added defense provided that they will cover the areas the enemy will attack. If you make it through the first attack, start mining Gas. Start building an Academy and research Stim Packs and the U-238 Shells upgrade. Start building a lot of Firebats. The Zealots will die quite easily to them especially when they are properly controlled and Stim Packed. You will find that Stim Packs will allow your Marines and Firebats to win battles when far out numbered. The enemy will be forced to build Dragoons to fight the Firebats. Build a ComSat Station so you can spy on the enemy's town and be sure to hot key it for easier use. If you decide to build an Engineering Bay, research the Infantry Weapons upgrade first, so units in Bunkers can benefit from it. If the enemy continues to produce more Zealots, start building lots of Firebats. Build Bunkers near your SCVs and place Firebats in them. Firebats are more effective against Zealots than Marines, especially when Stim Packed, but Stim Packed Marines will also do the job. Build up the tech tree to Vultures and start using them and Spider Mines to defeat the incoming Zealots. After that, getting Siege Tanks is probably the best decision. With Siege Tanks backing up your troops you will have a lot easier time fighting the Zealots, and Dragoons if your opponent finally starts mixing up his/her troops. If your Marines and Vultures are doing a good job, you may even want to skip Firebats and head straight to Siege Tanks. Playing Defensively
A more defensive order would be to build a lot of Bunkers and less Barracks/Marines. The problem you might find with that is the difficulty building enough Bunkers to properly defend your whole town. It's important to build a few near your mining SCVS to prevent Shuttle drops, and to pick off troops attacking your miners. If they do attack those Bunkers, quickly get your SCVs repairing them as they are being attacked.

Catch the Protoss by Surprise
A great way to surprise the enemy is to send a group of cloaked Wraiths to attack enemy Probes. Quite often Protoss players do not have Photon Cannons near their Probes, and if you are lucky, are not even in a position to build Photon Cannons or Observers because they have been focusing on building a lot of Zealots or Dragoons. Send your Wraiths in and attack the Probes. With 8 damage apiece for the Wraiths, you may find that they are the best target for them. If they do have Dragoons, you can cloak. This will not work every time but when it does, you can really halt the Protoss enemy's progress.

If the Protoss send Observers to detect your Wraiths, quickly ComSat the area, find the Observer, and kill it with the Wraiths. Then proceed to attack. Quite often the Protoss enemy will not have more than one Observer in the area and will be forced to build more, retreat back to the safety of Cannons, or move Observers from other areas. Stopping the Reaver Drop
Kill Reavers with Wraiths. If they attempt to return to their Shuttle, kill the Shuttle with the Wraith. Place Siege Tanks in Siege Mode near the center of your town to fire at the Reaver from out of range of the Reavers attack. Lockdown the Reaver if you can. If none of these are available, send Marines in, but spread them out so the enemy cannot hit them all with one hit, and use Stim Packs. One or two Missile Turrets back by your SCVs will help to chase off incoming Shuttles, and prevent your opponent from picking up the Reavers and moving them around your base. Stopping Mass Carriers
Lockdown can certainly help against large groups of Carriers. Build a collection of Goliaths with Charon Boosters upgrade (+3 Missile Range) can help the Terrans nail Carriers from a distance. Another option is Cloaked Wraiths. Use a Scanner Sweep to reveal Protoss Observers. Kill them, then send in the Cloaked Wraiths. If you're lucky it will take some time before another Observer can be moved into place. Dark Templar Rush
A really common strategy is a Protoss rush to Dark Templars. Protoss players will typically block their base in with Photon Cannons (which is a good warning sign) then rush to Dark Templars. Make sure you build a ComSat Station early on. Don't rely entirely on your ComSat station, they can be fooled. Build Missile Turrets around your town. Try to protect your Missile Turrets with a Bunker. Science Vessels are the best Defense against Dark Templars in the long run. Don't be caught unprepared. Defending Against Spies
If you want to keep the enemy from spying on your town with Observers, place a few Missile Turrets in areas that will cover your whole town. This usually halts most players from sending Observers into your town for fear of losing them. Lockdown, the Protoss Killer
Lockdown is a very effective tool to use against almost all Protoss units except Archons and Zealots. If the enemy builds a lot of Dragoons, Scouts, Carriers, or even Reavers, you can easily lock them down and finish them off with your troops by building up a sizable force of Ghosts with the proper upgrades. You can also use these same Ghosts to nuke the Protoss bases. EMP (or, "Oops, did you need those shields?")
The EMP ability of the Science Vessel is another very effective tool against the Protoss. EMP will reset all Protoss Shields/energy in the area of the explosion to 0. This can be useful in clearing out Photon Cannons, making buildings easier to kill, and even casting it on approaching Protoss armies. When being attacked by Archons, EMP will reduce them to only 10 hit points allowing a small force of even Marines to slaughter them. EMP is essential for fighting Scouts if your opponent is using Shield Batteries to constantly restore their shields.

Teren V.S Zerg

The Basics
You have a good idea what most Zerg players are going to do on land maps. It's usually one of three things: On small maps, they attempt the Zergling rush. If they don't use that, then it's often either a massive Zergling attack or a massive Hydralisk attack. The beauty of the Terrans is that they are equipped to handle all of those types of attacks quite easily. The same building order can be used for all three attacks. Build Barracks, Barracks, Supply Depot, then continue on either building more Barracks, or going Academy, upgrade, then more Barracks.

If the enemy continues with Zerglings, start building a lot of Firebats. If the enemy decides to go Hydralisks only, use lots of Marines. For a mixed attack, use lots of Marines with maybe a few Firebats to attack the Zergling. Make use of Bunkers for both offense and defense. After you win a battle, move outside the enemy town and build Bunkers. Bunker your way into your town. If you are placed on the defensive, simply build a few Bunkers, then place groups of SCVs by them to repair them while they are being attacked. The key is to keep up with unit production and resources. While you are building more Barracks to train Marines faster, Zerg players are building Hatcheries that can be used to mine resources also. To keep up, save up 400 Minerals for a second town. Use Bunkers for defense while this town gets into operation, then go back on the offensive. Progress up the tech tree to Siege Tanks. If the enemy builds 3-4 Hatcheries (like some players do) you are going to need 5-7+ Barracks to build enough Marines to stop them, less if Siege Tanks are also being built. Each Hatchery can train 3 units at once with a 4th coming soon after, while Barracks only train one at a time. You can overcome this by building more Barracks, and making use of Bunkers. If the enemy uses Mutalisks, Stim Packed Marines and Medics, if possible, should do the job. If they don't, use Bunkers with Stim Packed Marines while repairing the Bunkers. If the enemy attempts to use Guardians, try to build some Battlecruisers. If they are not available, use cloaked Wraiths. It's important to pick one thing and head for it. Don't attempt to get everything at the same time. If Zerg players focus on Zerglings and Hydralisks, stick with Firebats, Marines and Siege Tanks. If you start to see an opening where you are overpowering them, then continue on to Science Vessels for Defensive Matrix and Irradiate. You can also choose to instead build up a fleet of Battlecruisers. The key is not to do everything at once. Make sure you are able to hold the enemy off before spending all those resources to upgrade. Offense
With Terrans it's easy to sit back and do nothing because of their great defenses, but you have to take the battle to the enemy town if you expect to win. If you sit back while opponent takes over every resource spot on the map, it doesn't matter if you have a 5 to 1 kill ratio. You will lose eventually. The first group of attackers is usually a group of Stim Packed Marines (survivors of that early Zergling attack) and SCVs to build Bunkers on the front line. After that point, you will want to get Siege Tanks and Siege Mode and begin using that with your offensive. Then add in more Marines, Siege Tanks, Bunkers, and a Science Vessel to Defensive Matrix the Tanks, Irradiate packs of enemy units and spot burrowed units. It is also very important to bring at least 2-4 SCVs to repair everything while the fighting is going on. Using this method, you can push your way closer and closer into enemy towns overpowering large groups of Zergling, Hydralisks, and Mutalisks. Send some Siege Tanks, a few SCVs, and a group of Marines outside the Zerg town. Build Bunkers and place the Marines in them. Place the Tanks in Siege Mode and wait until the Bunkers are ready before attacking. When the enemy attacks, use 2-3 (more is always better) SCVs to repair the Bunkers and Tanks while they are being attacked. Once the attack is repulsed, move the setup closer and closer to the enemy town until it is destroyed. Move the Siege Tanks forward in pairs, making sure some remain in Siege Tank Mode while they are moving. Send a Science Vessel to Irradiate any clumps of Zerg units. Repair everything! Keep creeping towards the heart of your opponent's base while you repair and reinforce your troops. With effective management, a small group of Terran units can defeat a larger amount of enemy units, especially the relatively weak Zerg breeds. In this picture you can see a very nice offensive setup. The enemy eventually had to use Queens to Broodling the Siege Tanks, and Guardians. The Science Vessel used Defensive Matrix on the two Tanks, and a Marine is up in front to spot for the Siege Tanks. SCVs are around to repair during Battle. Marines are there to hit air targets and any unit that gets close to the Siege Tanks. All of this requires intense micromanagement however. Try to get Siege Tanks up on high ground. They make quick work of attacking Hydralisks. Get a moving line of Siege Tanks, Marines, and possibly some Goliaths heading toward the enemy. You can get a group of SCVs to repair them as they advance. You may find building Bunkers as you advance works well also.

Attack with large groups of Stim Packed Marines and Medics. It's amazing how much damage they can dish out, especially with upgrades. Build Bunkers outside the enemy towns then retreat to them.

If the enemy builds enough Zerglings and Hydralisks so this is not successful, look for openings where you can Dropship 8 Marines into the enemy resources. Often players do not plan for this. Again, Stim Packs will allow the Marines to tear apart enemy Drones before your opponent can respond.

If the enemy uses Ultralisks, use Science Vessels to Irradiate them, and Battlecruisers to Yamato them.


Dealing with a Flood of Zergling
The same ideas for fighting a lot of Zealots should also work here. Building 3-4 Barracks and making a lot of Marines and Medics should help fight off the Zergling rush. If they continue to use only Zergling, research StimPack, and use Firebats which are very effective against Zergling, especially when in groups and Stim Packed.

The Zerg player will often send Zergling to your town in long lines, and sometimes not even using attack move/Patrol, so by placing a few Marines near their path and Stim Packing you can slaughter large numbers of them before the enemy notices and responds. Hydralisk Hordes
Marines work best here, especially with Medics and the StimPack and U-238 upgrade. Bunkers also help a lot when you make sure to repair them while they are being attacked. Getting Siege Tanks as quickly as possible should be high on your list. Your next worry after defending your base with Siege Tanks and Bunkers will probably be Guardians, Terrans' worst enemies. You want to avoid using Firebats vs Hydralisks because they are not very effective against them.

Cast Irradiate on tightly packed groups of Hydralisks.


Guardians
You should be worried about the enemy using Guardians against your defensive set ups. Wraiths and cloaking can work here. Use the Science Vessel to cast Irradiate on groups of Guardians, and overcome the Guardians with masses of Marines. Another option is Golithas with the Charon Boosters upgrade (+3 Missile Range).

The best defense is to halt the enemy's Gas progress. Guardians require a lot of Gas, which usually means multiple Gas mines. Try to shut them down. Look for an opening in the Zerg town, then Dropship a squad of 8 Marines, StimPack them, and attack the Spire. If you can destroy the Spire, it will take the enemy quite a while to build another one, then upgrade it to a Greater Spire. This is often a very good defense against Guardians. Spotting expansion towns with ComSat and landing Marines on them is essential to halting the Zerg economy and troop production. Queens
Queens can also be a headache, with their ability to Broodling your Siege Tanks and Goliaths. Ensnare and Parasites are something else to watch out for, although killing the Queens is the best defense against that. Use Wraiths against Queens, as Battlecruisers are often too slow. Scattering Missile Turrets around your base can also chase off Queens. Use the Medic's Restoration ability to remove Parasites. Defilers
In the hands of a skilled player, Defilers can be serious trouble. A trick you might see is Defilers casting Dark Swarm, then hiding Hydralisks inside the cloud. Only the Firebat and Siege Tanks in Siege Mode will be able to attack units under the Swarm. Although this is a little seen tactic, it can be very effective against anything but Siege Tanks in Siege Mode and Firebats. Using Irradiate is probably the best counter to this strategy-- your opponent will be forced to move his/her troops away from the Swarm or risk having several of them die from the radiation. Science Vessels are also a great tool for killing Defilers, even if they are burrowed. Mutalisks
If the enemy is using Mutalisks on you, large groups of Stim Packed Marines with Medics work the best, especially because they are so portable. Goliaths, Missile Turrets, and Wraiths only do half damage to the nimble Mutalisk, lessening their effectiveness. Again, Irradiate is an excellent weapon to use against clumps of Zerg, and once you have a fleet of Battlecruisers Mutalisks will quickly fall before you. Valkyries are the best defense against hordes of Mutalisks on the move. Build several Starports then build several Valkyries at a time. Lurkers
Beware of the Lurker Rush or drop. Place a few Siege Tanks in Siege mode around your base. Build Missile Turrets around your base so they can reveal any Lurkers that might enter your town. Make sure your ComSat station is ready to do a Scanner Sweep. Siege Tanks and a Scanner Sweep is usually the easiest way to defeat Lurkers however even Wraiths can do the job. As you push toward the enemy build Missile Turrets along the way to fall back to if Lurkers show up. ComSat Burrowed Units
If the enemy uses Burrowing against you, ComSat should take care of that fairly easily if you see them burrowing. You may also want to scout around the map with Science Vessels to make sure the enemy is not creating a mass of burrowed forces for attack. Marine/Medic/Science Vessel Combo
Marines, Medics and Science Vessels work very well together against Zerg. Build large groups of Science Vessels, research the Reactor upgrade, and Irradiate groups of Hydralisks, Zerglings, Mutalisks and Guardians. Cast Defensive Matrix on Marines-- those 250 extra Hit Points will go a very long way. Rumor has it that a well-known Ladder player lost to a group of 20 Stim Packed, Matrixed Marines, and was extremely embarrassed. Infested Command Centers
Occasionally the enemy will try to destroy and Infest one of your Command Centers. Needless to say, this is not something you should allow. Move your Command Centers to fortified areas after they are done mining a group of resources so you can keep them defended. ComSats are cheap to rebuild, and Nuclear Silos will become a priority target, anyway, so you'll want all of your Centers under a watchful eye. Key buildings
Destroy key buildings such as the Hydralisk Den, Spire, and Spawning Pool. Then destroy the main Hives and Lairs. This will force the enemy to upgrade a Hatchery, then build the buildings again which can take a quite a while, delaying the enemy's production of those units. It's often quite easy to get a group of Stim Packed Marines into an enemy town to destroy key buildings, if you are tricky about it. In the screenshot to the right, the Terrans are attacking a Hydralisk Den to prevent further Hydralisks from being built. Destroying the Drones is also an option, but if the enemy has multiple towns, it will be more damaging to lose the Hydralisk Den as the other Hatcheries at other resource spots can still bring the money in. Ultimate Offense
The ultimate offense against the Zerg is a large fleet of Battlecruisers. To pull this off you need 2-3 Starports building Battlecruisers (3 or more is preferable), and build 2 Armories to upgrade both Ship Weapons and Armor at the same time. You will also need 2-3 Gas geysers. You can get by on only one if you do not spend any Gas at all except on the two Marine upgrades at the Academy and on buildings. (No Firebats!) Once you have about 6 Battlecruisers, you will be ready to make an initial attack. If your attack doesn't go as well as you wanted it to, retreat and wait until you have repaired your Battlecruisers, giving you time to build more. Head out again with about 9+ fully upgraded Cruisers and deal some damage. Many Zerg players do not understand the power of Battlecruisers. They may have not seen them in numbers, and used properly before. A common misconception is that people can't build up a large force of Battlecruisers and still attack. This can be done easily on even one resource spot. By just spending a few Minerals on Stim Packed Marines with U-238 shells, you'll have plenty of resources to build up to Battlecruisers. While this is easier on island type maps, this can also work well if the enemy isn't producing large numbers of Hydralisks and Zergling. A few Bunkers with lots of SCVs repairing them while they are being attacked can be enough to defend the town against less experienced Zerg players while Battlecruisers are built up. Once deployed, some Zerg players think that Cruisers can be killed with Mutalisks or Scourge. A group of Battlecruisers can easily defeat huge numbers of Mutalisks and Scourges, provided they are well managed and constantly repaired, something many Zerg players don't understand. Your biggest worry with a Cruiser fleet is Ensnare and Plague. Scourge, except in very large numbers combined with baiting attacks, and Ensnare will not be a problem. Use Yamato blasts to destroy Spore Colonies. Try not to directly assault groups of Spore Colonies if possible until you have overwhelming numbers. Use Yamato on Overlords to slow down Zerg production and blind your opponent. Your Battlecruisers should rip right through everything except extremely large groups of Hydralisks combined with special abilities. Make sure to regularly repair all your Battlecruisers when they get about 1/2 way damaged. This strategy works very well on island games and on most games where the enemy isn't very careful about attacking your expansion towns. The key to this strategy is conserving Vespine Gas. Try to use Mineral-only troops, such as Marines, Bunkers, and Missile Turrets. Build a few Siege Tanks as necessary, but hold back on all non-essential upgrades. Your biggest danger is an experienced player with Defilers-- Dark Swarm and Plague combined with packs of Hydralisks will quickly reduce your shining fleet to scrap metal. You might consider building a Science Vessel or two to complement your Cruiser force with Defensive Matrix and, more importantly, Irradiate.