StarCraft/Protoss 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, turtling is a basic and is highly effective against computers.

Bunker Rush
In a low mineral map, this is very common to see in maps such as Lost Temple or Luna. To do this, the player needs to scout early with the 7th SCV and while doing the basic build (8 SCV supply depot then barracks), the player needs to build a bunker near the enemy base (usually an expansion) and the barracks should already be finished and the player needs to make a marine as soon as possible and rally point near the bunker in order to arrive and go inside the bunker. If the plan succeeds then it should be a high advantage and this is great against a zerg player or a teching protoss player.

Opening Strategies

 * Zealot rush &mdash; during the first few minutes of the game, rush into the enemy's base with at least 4 Zealots. If your forces have an obvious superiority over the enemy, destroy their base as a whole. If not, try disrupting their mining operation as much as possible to cripple your enemies' abilities to retaliate in the long run. This is often done by setting the zealots to move straight to the resource collection area to attack the resource gatherers, after running by and typically taking nominal damage from enemy forces concentrated in a front area of the base. A common mistake of amateurs is to try to run the zealots through in attack-response mode, so that any engagement by a frontal defense at the base distracts the zealots into battling the defending units, leaving the resource gatherers to continue their work unimpeded.


 * Dark Templar rush &mdash; This tactic involves a rush of Dark Templar, typically 1-3 for an early game edge. Works very well against Terran; also works very well against Protoss if the enemy does not yet have any cannons, though even a single cannon, allowing other combat troops to attack, often effectively neutralizes a dark templar rush; it is often somewhat useful against Zerg players, because the few and extremely slow Overlords they have in the early game can not provide detection everywhere. This strategy is high-risk because it requires the user to ignore defense and early game units, and tech straight towards Dark Templars, if there is to be a realistic chance of catching a Protoss or Terran opponent before they have detection capabilities. Dark Templar rushes are frequently used in high level competetive play, and even if it fails to properly cripple an opponent, it might prevent an early attack. Just a couple of these can easily wipe out an entire mineral line or take out a single Turret or Comsat Station to further avoid detection without loss.


 * Defense &mdash; Another good strategy is just to build defense by building a whole bunch of Photon Cannons. These defenses structures are the best of any race in the game and should be used to help protect yourself while you mine and create a massive army.

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. However, when doing a dark templar rush in a low mineral map, it is best to hide the templar archives and the citadel of adun in order to make the dark templars a surprise attack. Also keep in mind that if your enemy is Zerg, this rush is useless as Overlords are detectors and are required for the Zerg race.


 * Early cannon rush &mdash; This strategy takes a lot of speed and luck. In some Starcraft maps, such as the popular Big Game Hunters or Korhal of Ceres, the mineral fields of certain starting positions contain a pocketed area behind the mineral field with a single 2-matrix-wide entrance, small enough that a Probe may seal itself in by constructing a Pylon at the entrance of the pocket. It may then warp in one or two Photon Cannons as a Forge is completed back at the base. The cannons' positions make them impossible to reach without first destroying the Pylon, which has a combined total of 600 points in shields and structure. This usually occurs in the first three minutes of the game, so the aggressor is almost always left completely defenseless at home. Most of the time, however, the defender has not had enough time to set up proper unit production, and if the cannons are warped in without the Pylon being destroyed quickly, the nexus of the defender is at risk of being destroyed, which may prevent the player from mining any more minerals (if they do not have the 400 minerals required for a second Nexus), essentially taking them permanently out of the game. Counters to this include the construction of Sunken Colonies or Bunkers near the mining areas.


 * Standard cannon rush &mdash; This tactic involves building Photon Cannons just near the enemy's base, so that (if properly positioned) they can attack the opponent. Usually, the Photon Cannons are placed so that they can kill enemy workers attempting to gather resources. Anywhere between one and three Photon Cannons can thus cripple the enemy at a relatively low cost. The popularity of Cannon rushes means opponents are often prepared to prevent them, which requires rushers to find new variatns of the strategy. Both Zerg and Terran have defensive structures much less suited for rushing. Sometimes, a player who rushes with Photon Cannons forgets to defend his own base, leaving him vulnerable to an attack.

Second Round / Post-Opening Strategies

 * Dragoon charge &mdash; Similar to the Zealot rush, but requiring more time, a group of 4-12 Dragoons can wreak havoc in the early-middle stages of a game. In addition to the Zealot strategies, the long (upgraded) range of Dragoons often enables them to hit key targets with impunity, especially if the enemy is overly reliant on static defense. This is particularly useful versus Terran, if the opponent's Refinery can be taken out before Siege Tank production starts. Counters to this include the wall-in, strategic Bunker placement, Stimpacks, and U-238 Shells. It should be noted that mass (24+) groups of Dragoons are often effective, but are terribly vulnerable to both Siege Tanks and Zerglings.


 * Mass zealots &mdash; A surprisingly effective maneuver that maximizes the ease and simple power of persisting with a lower-tech approach, this strategy focuses on simply accumulating a large number of gateways and pumping out more and more zealots - although crucial mid-tech advantages to be sought with this strategy are the zealot speed upgrade, available from the Citadel of Adun, and Forge upgrades, particularly for ground unit attack and defense. Some complementary dragoons may be mixed into the zealot hordes, or better yet, this strategy is coordinated with a teammate who focuses on complementary units, such as dragoons, marines, mutalisks, reavers, or even high templars; corsairs are a particularly effective complement. But even if the zealots must bear the brunt of air-to-ground attacks with no anti-air, their sheer numbers make it difficult for an enemy to cut their numbers quickly (unless a splash or area attack is used), and the mass zealots can often inflict serious damage before they can all be taken down; and the robust simplicity of this approach means that by this point, you have probably had plenty of time to produce another wave of zealots, and potential complementary units. This approach is not without its limits, however; groups of Terran Vultures with Spider Mines, Zerg Lurkers or Protoss Reavers, as well as heavy static defences, can hold off mass Zealot attacks indefinitely.

Mid-Game Strategies

 * Reaver Drop &mdash; This requires a substantial investment in tech, up to the Robotics Facility and Robotics Support Bay, which can't realistically be done without dividing one's focus on more standard base defense; but once prepared, if the enemy has not developed comprehensive defenses, can still wreak havoc, even with a small-scale expedition. At least one shuttle and typically one or two reavers are produced; as soon as the reavers are ready, scarab production is begun, the reavers are set on a control group and loaded into the shuttle(s). A safe route has preferably been scouted out, along which the shuttles are flown, away from the attention of any enemy forces, around to the back of an enemy base; the reavers are then dropped on the enemy base, typically beginning near the production pile, behind the minerals or even between the minerals and base, directly among the resource gatherers. Additional scarab production is begun as soon as the reavers are out. The reavers fire their scarabs at the resource gatherers, which are typically tightly congregated and particularly vulnerable to the scarabs' splash damage. A dramatic number of the resource gatherers can be wiped out in a surprisingly short time in this manner, crippling the enemy's economy. The inexperienced often have their defensive forces heavily concentrated in a forward position in anticipation of a land attack, although this becomes less typical as the game advances. The enemy then tries to summon the defending combat units back from the forward position to the production pile area. Even then, however, it is often surprisingly effective to load the reavers back onto their shuttles (giving the command to the reaver control group, rather than the shuttle, for a speedier upload), fly the shuttle to the opposite rear corner of the base, and unload them again; any ground units that have been gathered toward the reavers' original location have to traverse the typically very densely packed central base to approach the reavers again. Because of the reaver's significant investment, it is also often worthwhile to pack up the reavers and fly them off in retreat if they sustain significant damage, rather than let them fight to the death, then use them again a bit later when their shields have restored.
 * A reaver drop can be effectively defended against by providing defensive capabilities surrounding all sides of a base, and maintained in close proximity to the production pile itself, so an airborne attack force will not be clear of the defenses upon penetrating to the core of the base. Photon cannons or sunken colonies placed in immediate proximity to the mineral pile is often an effective defense.
 * A reaver drop can be paired with complementary units, at the expense of additional time and production prior to deploying the reaver drop expedition. Zealots, dragoons, and dark templars are all useful in helping defend the reaver while it provides the brunt of offense, particularly by keeping them close to the reavers. Keeping the reavers well-positioned is also very important; they can be fairly idiotic if left to move around on their own; often it works well to keep them stopped in a particular spot and just let the scarabs fly. An observer is often an indispensable companion for the reavers. High templars can be very effective when dropped together with reavers, although this operation requires an intense level of rapid micromanagement. Corsairs are a favorite pairing with a reaverdrop; not only can they help keep the skies clear above the reavers, and defend the shuttles in flight, but their disruption webs and the reavers' scarabs are a perfect complement for a devastating attack. This is particularly true when facing siege tanks, one of the reaver's deadliest foes, but which suffers horribly under the influence of both a disruption web and an angry reaver.
 * The reaver drop was popularized in tournament games in 1998 by the player known on Battle.net as Zileas, then an underclassman at MIT, whose quickness with coordinating the reavers and shuttles were described as "like a shuttle that fires scarabs".
 * A variant of the Reaver Drop is the Reaver Recall, in which an Arbiter's recall ability is used to immediately transport Reavers (and possibly other units) into the enemy's base much like Shuttles. This saves the trouble of building, loading, micromanaging, defending, and unloading Shuttles, but at the same time, drastically reduces the attacker's ability to retreat. This can be solved by using dual Arbiters. One Arbiter is used to recall Reavers to the enemy base and after they have unloaded their scarabs, an Arbiter back at the base is then used to safely recall this assault group back to the base. The Arbiter also provides cloaking to the Reavers. Of course, this strategy is both slow and expensive compared to the regular reaver drop. The best defense against this is to stop the Arbiter in the first place, but Zerg Lurkers with Overlords or Spore Colonies to detect the Reavers best exploit the tactic's poor withdrawal capability. Terran can accomplish something similar with Siege Tanks in siege mode and Missile Turrets or Science Vessels to provide detection.


 * Combined Carrier-Arbiter Attack &mdash; Although Carriers are relatively expensive and quite vulnerable on their own, combining them into a single group (not spread out) and adding the cloaking ability of the arbiter, they could easily be used to destroy entire defensive formations and bases of any of the 3 races with minimal loss of units. The key to this tactic is to never use Carriers on their own, but to always combine them with at least one “Arbiter”.  In order for this tactic to be successful it requires constant intervention from the player in order to maintain the very fragile formations in this method.  4-12 Carriers are grouped and then sent towards an enemy base (or large formation). As long as the Carriers are within the effective range of the Arbiter, they cannot be targeted effectively (as they destroy all detectors close enough to reveal them).
 * By far the best defence against this tactic would then be to try and destroy the Arbiter behind the line of Carriers, this can be done by flying/moving units (Corsairs, Scourge, etc.) around the offensive line and concentrating all fire on the lone Arbiter. This needs to be done quite quickly, as a group of carriers can quickly cause enormous amounts of damage.  Once the Arbiter is destroyed, the remaining force is vulnerable and can be picked off more easily.

Defense Strategies

 * Photon Cannon Placement &mdash; A common mistake among amateurs is to rely too heavily on Photon Cannons, placing too many of them close together in "cannon farms" or concentrating them in bottlenecks of anticipated attacks. The opponent can easily counter this by investing in air forces that can bypass the cannon farms, or by developing an antidote to the cannons such as Guardians. Either way, the heavy investment in stationary artillery is neutralized, and the enemy's superior investment in mobile units is likely to pay off. Also, as enemy units receive upgrades, the effectiveness of cannons degrade over time. Cannons should either be in tight clusters so that they can defend each other, or scattered to maximize their ability to detect cloaked units. Another common mistake is to power a group of many Photon Cannons with only one Pylon, which allows the enemy to simply destroy the Pylon powering the Photon Cannons before they have time to cause substantial damage to the attacking force. Even a simple cluster of a few Pylons or a number of overlapping Pylon fields is enough to solve this problem. Experienced players often use pylons or other buildings to prevent melee units from properly attacking their Photon Cannons.


 * High Templar On the Home Front &mdash; Keeping several High Templar near the base often proves to be an invaluable component of defense, particularly in combination with Photon Cannons and Dragoons. Having High Templar that can get just within range of a bottleneck the enemy is trying to pass through, in a tightly packed crowd, can have brutal effects on attackers. Keeping a few High Templar wandering around the core and back areas of the base can provide effective aerial defense. If an invasion continues when the High Templar have expended all of their energy, it is often worthwhile to merge them into Archons. By waiting for the Templar to regenerate enough energy for further Psionic Storms while an enemy is actively advancing, a player risks losing them and wasting their potential.


 * Defensive Reavers &mdash; A few Reavers buried deep behind the Zealots, Dragoons and Photon Cannons forming the front and secondary lines of your defenses can greatly augment their defensive power and can be very difficult for the enemy to effectively counter. Remember not to bury the Reavers too deep, since Scarabs have to circumvent every unit on the way to the target.


 * Defensive Carriers &mdash; Carriers are expensive units with both extreme strengths and weaknesses. Though their firepower is not overly impressive compared to their cost, they are able to fight efficiently in large packs. Seeing as most good counters to Carrier armadas are ground based, their aerial mobility makes them excellent for hit-and-run tactics. They also are invaluable in controlling isles - parts of the map separated by water or other terrain limited to air units - because it is difficult to muster large ground forces to defend such areas. Tightly packed Carriers are extremely suspectible to the Zerg Defiler's Plague spell, which leaves them with nearly no hitpoints.

Zerg Strategy
The Zerg excel at quick generation of armies, making them highly flexible. Each Hatchery produces a maximum of 3 larvae and a new one every 20 seconds, making it easy to grow new units, and every Hatchery can create any available Zerg unit, unlike the specialized factories of the other races.

Their return cost is building expenses. Each Hatchery/factory is extremely expensive (300 minerals and 120 seconds of build time, compared to for instance the 150-mineral 80-second Terran Barracks), and furthermore, each new structure must be grown from a Drone (50 minerals, 20 seconds). Defensive structures are even worse: the Drone must be hatched and then turned into a Creep Colony, and then the Creep Colony must be turned into a Sunken or Spore colony (for a total of 175 minerals and 80 seconds). A lost building is worse for Zerg than 10 lost units.

Because of slow building and Drone sacrifice, and moreover because of the need to build drones with the same limited early larva supply used to build attack units, Zerg have the weakest starting economy. They make that up with their Overlord, which can be immediately sent to scout, and the serendipitous discovery of an enemy base can lead to an early attack, something the Zerg excel at. An early-game strike at the enemy's mineral line will usually even the odds, if it doesn't hand the Zerg the advantage. Since Hatcheries allow the building of 3 units at once, if the Zerg survives to mid-game, they tend to catch up and even push ahead of the other economies. Their cheaper hatcheries relative to the other race's "town center" buildings also makes it easier for the Zerg to take multiple expansions.

Zerg are particularly weak against well-defended choke-point unless you use a trump strategy. Due to the cheap cost of units, Zerg fighting power cannot be concentrated onto one choke point efficiently. 24 Zerglings can be stopped on a cliff, blocked by 3 Zealots. It would be much wiser to attack from a different angle. In general, fighting in open space is best for Zerg.

Against Zerg
When Zerg face off against each other, the game gets fairly predictable. Zerg vs Zerg games usually involve only three types of attack units: Zerglings, Mutalisks, and Scourge. This is primarily because Hydralisks are not effective against combined Zergling/Mutalisk forces. Devourers are also sometimes used if the game lasts a long time. The Queen's Ensnare spell, though rarely seen, can also be very useful in Mutalisk air wars.

Another advanced tactic would be to "nydus" your enemy base using the Nydus Canal. Although, very hard to pull off and would give away your tactic (ie. ground units, zerg race), if achieved, could hinder your opponent to a significant degree. This tactic requires early scouting to first know that the opponent is indeed Zerg and would also require exposed creep in your opponents base that isn't defended so the Nydus Canal can spawn successfully. Of course, one may go to the extreme and construct more than one Nydus Canal, then try to make exits for each one.

Against Terrans
When the Swarm confronts Terran foes, it usually faces one of two main tactics. The primary strategy employed by Terrans, the dreaded tank push, is as effective against Zerg as any race. A prepared Cerebrate has several effective counters. Burrowed Zerglings are capable of lying in ambush for approaching tanks and emerging practically on top of them, too close to hit. When protected from Marine fire under the cover of a Defiler's Dark Swarm, Zerglings can quickly surround and destroy enemy tanks. Tanks can also be neutralized by a Queen's Spawn Broodling. This is especially effective if the enemy deploys tanks in small groups: a tank that is suddenly turned into Broodlings will attract the fire of other nearby tanks, distracting them, and damaging tanks or infantry close to the Broodlings. This can also be used in the middle of a group of Marines, or as a cheap way to damage Bunkers prior to a base assault.

In the Brood War expansion, Zerg face an additional threat: pure infantry armies of Marines and Medics, affectionately nicknamed M&Ms. These can deal significant damage to Zerg forces while sustaining frustratingly few losses. Fortunately, the Zerg now have Lurkers, which are especially good at countering large groups of infantry. Lurkers benefit especially from good unit control: a cunning Cerebrate will note the approach of infantry and continually order his Lurkers to hold their fire until the enemy troops are right on top of them. This will greatly increase splash damage, and, when combined with surface troops, makes it difficult for the Lurkers to be targeted, even after being detected.

In extremely long games, Terrans sometimes opt for a large fleet of Battlecruisers. These intimidate some Zerg players, as they have no equivalent capital unit, and large groups of Hydralisks will be quickly mown down. Queens and Defilers are the answer here, as Ensnare and Plague will cripple the enemy and render them unable to escape. In Brood War, Devourers and Mutalisks are a highly effective combination. Scourge also show their quality in this situation, as they can take down expensive Battlecruisers for much less cost. However, one must remember that, if unescorted and unaided, no amount of Scourge can score a hit on groups of six or more upgraded Battlecruisers. Their upgraded weaponry will take Scourge down in swarms.

Terrans have few special abilities that are trouble for the Zerg. Irradiate can be highly annoying, as a single use will destroy an Overlord or Lurker and can massacre a clump of Mutalisks. It is largely ineffective against other units, however, due to the extremely long time it takes to work. Burrowing the affected unit is the best defense when it is used on a pack of Hydralisks. Nuclear strikes should not be a problem as long as you keep Overlords in every base.

Finally, although Infested Terrans are entertaining to use, their effectiveness should not be overestimated, as they are rarely able to reach their targets without dying. Dark Swarm can be used to prolong their lives, but it does not effectively protect units from splash damage. In allied or team games with a Terran partner, however, Defensive Matrix can drastically alter that.

Against Protoss
Zerg players have a bit of an advantage against Protoss, due to the fact that Protoss have no reliable early scout (Probes die in two hits from Sunken Colony, Corsairs are a bit late, and Zealots have a hard time making it into a good Zerg's base). For this reason, Protoss players have to play a guessing game regarding the Zerg's strategy until they have reliable data. Generally, Zerg players pick a strategy at the start and later on change it to throw the Protoss off balance. Mutalisks, due to their small size, are fairly resistant to Dragoon fire, and of course are completely safe from Zealots. High Templar, however, will decimate them if they pause in mid-flight. Hydralisks, if micromanaged properly, can defeat Zealots without taking a single hit. Zerglings destroy Dragoons due to their small size and speed.

The Zerg will typically have massive numerical superiority against a much smaller army of far tougher units. The clever Cerebrate will turn this into an advantage by dividing his forces and attacking from multiple fronts. This has the added benefit of dispersing your troops, providing some protection from psionic storm -- vital in Zerg vs. Protoss matches. A well placed storm can destroy a dozen or more clustered Hydralisks in seconds. Individual High Templar can be destroyed with Spawn Broodling, but an intelligent Executor will trick you with hallucinations while hiding the real Templar in Shuttles. The best solution is simply to prevent large groups of units from piling up in the first place through constant harassment.

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 5 more drones (for a total of 9, the maximum supply availible (1 Overlord (8) + 1 Hatchery (1))) as soon as you can and order those to mine too.
 * Variation: Order one Drone to build an Extractor so that your supply goes down to 8. Hatch a drone, cancel the Extractor, and order the drone to mine again. This way, you have 10 drones with only 9 supply.

When you reach 200 minerals, order a drone to morph into a Spawning Pool. At 100 more, hatch an Overlord (it takes less time to build than a Spawning Pool and you won't need it until the Pool is done).
 * Variation: Do the Extractor trick again for another 10th Drone.
 * Another variation: Since Zerg buildings can be built on any creep (including that of another player), send a Drone to your opponent's base and order it to morph to a Creep Colony. Once this is done (probably after the Zerglings hatch), morph the Creep Colony into a Sunken Colony. Obviously, this only works if your opponent is also Zerg and pays no attention to his/her own base.

Once both (the Spawning Pool and Overlord) are 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 one/some marine(s) inside (repair it during the attack with an/some SCV(s), or just get plenty of Marines early. Since they have range, some marines can attack while others move backward. You can also put them behind buildings so that the Zerglings must run around the buildings, giving you extra time to fire.
 * Protoss - Build two gateways and try to have two zealots come out by the time the Zerglings arrive. 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). You can also get a Sunken Colony to protect your base, although some players do not recommend this as it is too defensive.

Lurker Rush
Lurkers are fun to use against Terran and Protoss because of their lack of mobile detectors in early mid-games and therefore can be used to secure vital locations early on. 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.

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 Missle 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.
 * Protoss - About two Photon Cannons placed near your resources or a choke point (if there is one) and/or Observers.
 * 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 and also high templars and an archon.
 * Zerg - You own Mutalisks, and Scourge.