StarCraft/Strategies

Terran Strategy
If you happen to be playing on a Fastest Possible map, you can use bunkers to block the entry of land-bound units into your base. This, along with placing turrets on the sides of the base that can be accessed via air, is known as turtling and is effective at stopping most simple rushes.

However, Fastest Possible maps are not what mainstream players play and doing this on a non-fastest will simply waste minerals and give your enemy free access to all parts of the map, increasing his resource yield, because you are not actively attacking him and claiming expansions.

For attacking, you need to rush to factories+workshop to produce siege tanks. Research siege tech (ability to go into siege mode, range=12, dmg+70 +5 for each upgrade), move outside the opponent's base. Support them with bunkered marines, goliaths (optional, anti-air), missile turrets (detectors) or spider mines.

Ghosts
Ghosts are the most versatile units in the Terran armada. They can be the difference between defeat and victory. For one thing, they have cloaking. That already gives them an advantage. But they are also great at halting attacks. If your opponent brings in a battlecruiser, no sweat, just use lockdown and the battlecruiser will be a sitting duck for your other units. When you have found the location of the enemy base, this is where the fun starts, assuming you have two command centers: one with comsat and one with a nuclear silo armed and ready. Use the comsat station to check and see if there are any enemy units with the detector ability. If there are, roll in some tanks in siege mode and blow them to hell. After you've cleared a path for the ghost, he can run through in stealth mode and set up a marker for a nuke. If you're very high on resources, you can send a few tanks to another base, causing your opponent to be distracted by the ensuing battle. Just be careful that a Science Vessel doesn't happen to be driving by, or your Ghost is as good as dead. I only recommend sending Ghosts in when you have all of their abilities researched. The only downside to Ghosts is the fact that they don't really hold their own in direct combat. In terms of fighting, put them in bunkers.

Counters
 * Terran: Build a tight perimeter of missile turrets or put science vessels on patrol.
 * Zerg: Spore colonies and overlords.

Science Vessels
Another useful unit. Science vessels are unable to engage in direct combat, but are great at defending, assisting, and scouting. If you have an important unit under heavy fire, the defense matrix works wonders. If it's used on a Ghost who is about to bomb a base, it will be near impossible to stop. The EMP is useless if you're not fighting Protoss, but is excellent against them. If it's fired in the middle of a cluster of Protoss units, they'll find their shields gone and easily killed by a group of marines. As for irradiate, it will spell absolute doom for the Zerg. Since it targets biological targets exclusively, it'll take down most of their buildings and units caught in the blast. Finally, in terms of defending, putting the science vessel in patrol mode will catch most cloaked units of guard. If you watch the energy meter and use it wisely, the science vessel is an investment you won't regret. Another strategy involves 2 science vessels, irradiate and cast defensive matrix on each other and tell them to run around in a zerg base (it is more effective than irradiating the opponent's unit instead because they can just move that unit away from the others).

Photon Cannon Rush
This rush is very effective but very risky. It is also known as a 'cheese' tactic, used most often by newbies against other newbies, as an experienced player will scout and discover (and eliminate) the fledgeling attempt...leaving the attempter's economy in dire straits.

First, keep make up to six probes and make a pylon. While the pylon is being built, send one of your probes to find your enemy. Then, when you make up to eight probes, make a forge. Note that you should place all these buildings inside your main base. While the photon cannon is being built, go and make another pylon right at the end of the enemy's base's entrance. This is when the risky part comes.


 * 1) The enemy could have already built defence on the entrance, that means that your plan is a failure.
 * 2) The enemy's allies could prevent you from making pylons
 * 3) etc.

A faster method of rushing with photon cannons is to make your first pylon directly in the enemy's base, along with the forge. This would increase your chances of detection (as the forge is larger) but increases the speed at which you can get cannons built (since you save the minerals you would have spent on the pylon in your home base).

Anyway, after you've built the pylon, make some photon cannons. Don't forget to make some defense in your base too. After you built enough photon cannons on the entrance, you should go deeper and deeper into the enemy's line. When the person figures out about the entrance, he/she could be too late to do anything about it. And when he/she tries to attack, just keep making more photon cannons.

A more sophisticated technique usable only on certain maps (and sometimes only certain positions on those maps) involves moving the probe behind the mineral line and building pylons to block the wall. The requirements for this technique involve a space between the mineral line and an obstacle of a size such that only a pylon will fit in between them. Hence a probe can sneak into the enemy base, wall itself in between the pylons and warp in a photon cannon once the pylons are completed (Note: A forge should be completing at your main base in the meanwhile). Obviously, your opponent will be doing their best to tear down the pylons before they warp in, before the photon cannon completes and before the photon cannon kills all of his/her peons. The lapse between the completion of the pylons and the arrival of your photon cannon is quite large, and your opponent is highly likely to be able to destroy one of your pylons (and the wall-in) before critical damage has been inflicted. The rather tricky solution to this is to carefully watch over the health of the attacked pylon, holding 100 minerals and your probe ready nearby, such that as soon as your opponent destroys the pylon, you immediately re-build another one in its place.

Photon cannon rushing is less effective against Zerg players as they tend to have the fastest rush in the game: this means that they are more likely to attack you before you have anything set up. Furthermore, they can simply race their zerglings past your photon cannon emplacement to attack your undefended (or at most, barely defended) main base.

Dark Templar Rush
Because Dark Templars cannot be seen unless in the range of a detector, they are quite useful to use before your opponent(s) get detection. However, because they are also quite high up in the tech tree (Nexus>Gateway>Cybernetics Core>Citadel of Adun>Templar Archives), it is recommended that you build some sort of defense (Cannons, Zealots, Dragoons, etc.) while teching up to Dark Templars. An early assimilator is also recommended because they cost 100 gas (and 125 minerals) each. There are too many variations of the strategy to give a specific build order.

Reaver drop
This strategy is mainly used for destroying the enemy's workers, island games, and hit and run attacks. The suggested building order is: pylon, assimilator (you NEED gas), gateway (early defence), forge (optional), cybernetics core, robotics facility, and robotics surppourt bay. upgrade the scarab capacity and damage first, then create at least 2 reavers. Now make shuttles (1 for every 2 reavers, round up if the number is odd), you should try to drop the reavers at the enemy's mining location. Try to kill the workers to cripple their economy and if possible, destroy their main base too.

Zergling Rush
Try to play against your opponent in a small one-on-one map that you know very well. Send your four drones to start mining minerals and order your overlord to your opponent's base (to spy on him; no race starts out with anything to attack air early; by they time a Terran player gets Marines you should have your Zerglings). Hatch 3 more drones (for a total of 7) as soon as you can and order those to mine too. When you reach 200 minerals, order a drone to morph into a Spawning Pool. Once it is done, hatch 6 Zerglings (two for each larva) and rush to your opponent. If you are lucky, you will catch your opponent totally unprepared. Try to kill as many of his workers as possible and you will be guaranteed a win. If your Zergling rush fails, you will fall behind in mining resources. Most experienced players know about this rush and can defend well against it so be careful of whom you use this strategy against.

Counters:
 * Terran - Build an early bunker near your resources and place marine(s) inside (repair it during the attack with SCV(s), or just get plenty of Marines early). Alternatively, if the map you are playing on only has one entrance to your base, you can build Supply Depots and Barracks there to "wall" the Zerglings out.
 * Protoss - Build two Gateways and warp Zealots. Most Zerg players will be able to attack you before this, so you may need to attack the Zerglings with Probes. Alternatively, build a Forge and some Photon Cannons, although this is not recommended.
 * Zerg - Do the same thing. Because your opponent is rushing you, you have extra time to build defense (your opponent must make units and have them run to your base). Alternatively, you can also get a Sunken Colony to protect your base.

Lurker Rush
Lurkers are fun to use against Terran and Protoss because of Protoss' lack of mobile detectors in early mid-games and the fact that Terran players usually use infantry in the early game. This is very similar to the Dark Templar rush (Protoss) except it is slightly lower on the tech tree but much more costly in gas. Though there are countless variations, you should probably have at least 2 Hatcheries and some Zergling support. Also, note that you should start the Lair upgrade before building a Hydralisk Den.

Counters:
 * Terran - A Marine-filled Bunker with a nearby Missile Turret placed near your resources or a choke point. If you do not have an Engineering Bay (required for the Missile Turret), you can get an Academy (which is good for the Marines & Medics and Firebat strategies) and then add a Comsat Station to your Command Center. Once you are able to see the Lurkers, Siege Tanks are good at taking them out.
 * Protoss - About two Photon Cannons placed near your resources or a choke point (if there is one) and/or Observers. Dragoons are recommended once you can see the Lurkers.
 * Zerg - An Overlord; this strategy really doesn't work against Zerg.

Mutalisk Rush
Mutalisks are fast flying zerg units and can be really annoying if used properly. They are good to use against Zerg and Protoss, and maybe against Terran too. They require a lot of gas though so build an early extractor followed by another hatchery and a spawning pool. Upgrade the hatchery to a lair. Don't forget to make more drones and overlords in the meantime. Build defenses if you have to, but not too much. After lair is done, make a spire. After the spire is done, make 6 mutalisks and rush them to the enemy base. If there are no anti-air defenses near the enemy's resources, then whoopee! Kill all his workers. You can also kill his army if his troops can't attack air.

Counters:
 * Terran - A marine-filled bunker near your resources. A large marine army with medic support is also nice. Upgrade U-238 shells and stimpacks. The stimpack upgrade is also highly useful here and can of course be used liberally thanks to the medics nearby.  A fair supply of missile turrets are probably the best defense going for Terrans though.
 * Protoss - Photon cannons near your resources. Maybe early corsairs.
 * Zerg - You own Mutalisks, and Scourge.

Higher Level Strategies
So far, you've heard about build orders and rushes and counter tactics, but what about higher level strategies, that help you decide how you should rush, or what to do with those mutalisks once you have them? Here are a few guidelines that should direct your gameplay.

Know the map
The first thing you should do, even before the game starts, is to study the mini map. If you've played the map before, excellent. Look at the distribution of resources. Are there plateaus? Does it look like there are ramps on there? If it's a ladder style map, look for all the possible starting positions, and the general locations of the natural expansions. Take a guess where your opponent(s) will start.

Be sure to take notes on what lies between you and the likely base. This should be fairly obvious, but you should know if it's possible to walk over to their base, and how long that will take. If not, early ground units should be sacrificed for air units.

Have a plan
Not having a plan is probably the reason for 99% of my losses. It is tempting to build all the way up the tech tree, having some of every unit, letting them kind of sprawl all over your base, and expanding when you run out of cash. Unplanned growth is a good way to get killed by a more skilled player. Let's take a quick example:

I played a zerg versus terran game on a small map (96x96). I knew the three possible starting points on this 3-player map, so I had a good idea of where my enemy would be and how to get there. There were quite a few choke points, so amassing a huge army was not a good idea (I'm not convinced it's ever a good idea, but it depends on the game). I always seem to die a horrible death if the game goes on too long, so I would be attacking early. My plan looked like this:


 * Build zerglings as fast as possible.
 * Attack
 * When that fails (and it usually does) switch to lurker production
 * Build 3 or 4 lurkers
 * Attack

Now, an equally good plan might have gone something like
 * Tech straight to mutalisks, skipping hydralisks
 * Build 6 mutalisks
 * Attack
 * If that fails, tech to ultralisks
 * Build a few ultralisks
 * Ultralisk drop
 * Attack

In any case, the first plan was good enough. Even though I flubbed the build order and had my spawning pool out by the time my opponent was building his second barracks, it worked out for me. This brings up a minor point, know a good build order! You want to be able to attack/defend as fast as possible, and you don't want to spend that time trying to figure out if it's time to build a drone or spawn an overlord.

In any case, it turns out my opponent's plan was something like


 * Build a barracks
 * Scout with marines
 * Piddle about for a little bit (okay, not really)

By the time I got to him, his base was a mess. He had one barracks, an engineering bay, and a second barracks being built. My zerglings handily dispatched his construction SCV and the lone marine sitting by the finished barracks. Two more marines eventually came back from scouting, one at a time, but they too were devastated by the little insects. Eventually, he had to take many of his SCVs off of mining to fend off my guys. This setback cost him the game later on. The rest of the game went as follows:


 * He teched to firebats
 * My second wave of zerglings were mowed down
 * He started advancing
 * My lurkers arrived and wiped his infantry out as they came through the choke point
 * With resource gathering, production and unit count diminished, his base was demolished.

The moral of this story: he didn't have a plan, so he did the obvious thing: he started teching and scouting. While this is not a bad idea generally speaking, it was definitely the wrong time to do it. This early in the game, it would leave you completely defenseless and drained of resources to do that instead of getting some basic units out.

Now, it might just seem like I had a better plan, which is true. You might be asking, "How do I know if my plan is good enough?" Well, for one thing, your plan shouldn't be set in stone. Be dynamic and adapt to the situation at hand. Well, except for one element of your plan:

Your plan should always be 'Attack'
So this is really what I've been building up to this whole time. It's really the one law of StarCraft. Notice I made it ridiculously clear in my plans. Every other step was 'attack'. This isn't Civilization. You don't win a game by having a cooler culture than the other guy. You need to wipe them out, and the best way to do that? You guessed it: attacking. Do it often, and let it be the guiding force in your plan.

Here's how it works. When you attack, it's not just an exchange of blows, it's an exchange of information, and it's a two-way street. Let's go back to that example above. I attacked. Woo. That's already a path to success. By doing so, I learned the following:


 * I learned the location of his base
 * He had fewer resources, because he had obviously dumped them into an engineering bay and second barracks.
 * His units were either not being produced, or running around the map, leaving his base undefended.
 * Further unit production would be slowed, because he lost some SCVs to finish off the zerglings.
 * He had not yet built an academy, or there would have been firebats hanging around.

Here's what he learned:
 * I had some zerglings and my base was to the south (or my zerglings came from the south, same difference)
 * I was being aggressive, so a second wave was likely.

So it's a form of really aggressive recon. It's like scouting with the bonus of beating up a guy when you're done.

But now what? Your plan was 'attack' and you attacked. It didn't work. Well, it's back to the drawing board. What next? Well, what did you learn? He had no firebats. There's a good chance that a second wave of zerglings would work, but not for long, especially after that skirmish. So of course, his step is to defend from firebats. But for me, the beatdown would give me just enough time to get my lurkers out and about and attack again. If that didn't work, he would have turrets or a comsat station the next time I came around, so a new tactic would be required. But it did work, and I won, woohoo. It's really an iterative process.

The attacking does another thing. It puts pressure on the other player to keep up with you and keep adapting. It's an effective scare tactic. They get frazzled, and you can sit and gloat. The moment you let up the pressure, he will gather his wits, tech to something really big, and blow you away. And you don't want that.

It is almost always wrong to build a bunch of units and sit on them. That is another good way to end up hanging your head in shame. Here's what happens. You start building your units and letting them hover around in your base, or maybe on a street or back alley somewhere. Your opponent does the same, but with the pressure let up, he just builds a few guys to keep pestering you while secretly teching straight to carriers or ultralisks or what have you. It's like Murphy's Law in action. No matter what you build, your opponent will build bigger and better units and just wipe you off the map. You've spread yourself too thin to defend against any serious assault of one type. Sure, you can defend a bunch of minor assaults of various types, ground or air, but otherwise, you are hosed.

This is why it's important to attack. It keeps you in the loop, it keeps them off guard. You stay focused with a plan, and you build the right units for the job, rather than building everything and hoping that you have enough of each. Also, it kills dudes, and hey. That's how you win.