StarCraft/Protoss strategies

Hallucinating units
Hallucination (hotkey L) creates two duplicates of the target unit which do no damage.

Operational details & properties:
 * Hallucination works on both allied and enemy units; in either case, the hallucinations are marked as the caster's allies.
 * Hallucinations are instantly destroyed by any spell except Hallucination.
 * Some enemy spells, such as Ensnare, can vaporize multiple hallucinations in one cast.
 * Hallucinations lose HP/Shields twice as fast as normal units and have neither weaponry nor armor.
 * Hallucination forces an enemy to divert focused fire either upon fake units or spreading out the firepower.
 * Fresh duplicates can be created from other hallucinations.
 * Hallucinations do not produce any damage and do not cast spells, which make hallucinated Reavers, Carriers, and spellcasters very poor and easily identifiable imitations.
 * New ones appear out of nowhere, and players may be able to keep track of them.

Hallucinations serve two purposes: To deceive enemy players and to deceive the AI:
 * Enemies may waste costly spells on Hallucinations.
 * Hallucinations appear to attack and thus attract enemy units.
 * Hallucinations also serve as decoys, drawing the enemy's attention either to a distant place on the map or forcing the enemy to make poor decisions.
 * The superior numbers that this skill may grant can intimidate an opponent.
 * Hallucinations also serve well as scouts and cannon fodder, in which case their effects may be doubled by separating the two dittoes.

Special hints:
 * Hallucinated Arbiters are particularly cost-effective if grouped with a real one.
 * Hallucinated Arbiters can be defeated with a well-placed Stasis Field.
 * Beware accidentally using this spell on an Interceptor instead of the Carrier.

Zealot Rush
The zealot rush is one of the earliest attacks performed by the Protoss. It is also performed by the computer in skirmish matches, either by sending three zealots, or by constructing the full army of 12.

DTR
The Dark Templar rush is a mid-to-late game tactic involving an army dark templars. While they can inflict damage, they are vulnerable if your opponent has any form of detection units or aircraft. As such, they will need to be paired with anti-aircraft (such as corsairs). This only applies to the Brood War expansion, where the unit is introduced, and requires constructing the Citadel of Adun, followed by the Templar Archives.

When used alone, they are good for taking out distracted players, since economic units are killed in one hit by Dark Templars and do not announce that the forces are under attack. However, detector units that can uncloak Dark Templars will cause them to be less effective than a Zealot rush.

Reaver dropping
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.

It is very important that the command to load into the shuttle be issued to the Reaver and NOT the shuttle. Given the "Gravitic Drive" (Increased Speed) upgrade, the Shuttle becomes the fastest transport in the game. However, the speed boost the Shuttle gains builds up. For a few seconds after moving, the shuttle will not move at a very high speed, but will eventually build up to a very good speed. By having the reaver load itself into the shuttle, and not vice-versa, you can pick it up without stopping your shuttle, allowing it to retain its movement speed chances and reducing the chance that your opponents will catch your shuttle, costing you 400 minerals and 200 gas.

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.

Reaver Drop
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". This technique effectively prevented many ground-attack units from engaging the reaver, since it could drop, shoot and load back into the shuttle before they could counter-attack. The developers of Starcraft, in a later patch, responded to this by introducing a short delay to prevent the reaver from opening fire as soon as it hit the ground.

Harassment and Distraction
After an attack, once your reaver (or shuttle) begins to sustain significant damage, the best option is usually to retreat to a shield battery, have it restore both the reaver and shuttle's shields, and return to a different base and continue reaver-dropping. Hotkeying some of your unit-producing building can allow you to continue building up your main force while they're stuck trying to defend against the harassment -- In other words, you can mass an attack force in the seconds between reaver drops. That way, you can build an army while keeping them distracted.

This can also be done in reverse -- Instead of distracting with a reaver and massing an army, you can distract their forces with a few dragoons and then drop in reavers for the kill. This provides you with a better window in which to attack the enemy's key buildings and workers -- In PvP, a couple of reavers can take down pylons in a few seconds.

A great strategy when in PvT with the reaver drop is to pair a couple of dark templar's with the reaver, and drop them in front of a couple of bunkers -- unless the enemy has ghosts already in the bunker, it will outrange the marines in the bunkers and flush them out. Then you can snatch the reaver away with a shuttle, and the dark templars will take care of them, and force the enemy to rebuild their defenses. Unfortunately, this only works if you have reavers and dt's before they have ghosts -- which can be difficult.

Reaver Recall
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.

The Reaver Recall is much less practical than the drop. After building a cybernetics core, the Executor has three choices- Templar, Air units, and Robotics. The drop requires one tree, while the recall needs all of them. (robotics for the reaver, air for the arbiter, and templar because it is required for the arbiter tribunal.

Build Orders
Source: This build order archive was created by TwoTimer at www.blizzforums.com

Build orders are designed to best thrust you into your midgame pump. They create a good mining economy, give you credible rushing chances, and prepare you to expand. Any map with patches normal distance away from the Nexus/CC/Hatchery can adapt these build orders as printed.


 * Pay attention to any special commands or building placement, both are also a part of a successful execution of a build order.
 * Any specific matchups the build can be used against are also included.
 * Any special map conditions will be noted (such as long distance between mains, air map, hybrid map). The default condition is ground map.
 * Please assume workers are being produced between any gaps in number in the build order (unless it specifically says not to make any workers).
 * Any special mining situations will be expressed (such as more than 9-patch mains).

These are a generic set of builds that might alter slightly per map. They are not all specifically designed to be used on Lost Temple. If you practice the build, make sure you do it on multiple maps so you can see the differences. Note that the supply numbers are approximate, they might vary slightly per map, especially the deeper you get into the build.

A note on vocabulary for newbies: "Expo" is short for "Expansion", i.e. a building near a resource pool outside your main base.

NOTE: The following builds were specifically made for maps apart from the fastest money maps.

Protoss 9/10 Gate Zeal Rush
Matchups: Pvz, Pvp, Short distance locations.

Theory: This is the fastest way to rush zerg with zealots, while maintaining a decent economy. The build is all about cutting corners to get those zeals out as fast as possible. Against builds where zerg elected to make a hatchery before a pool, the zealots will arrive at latest by time the hatch finishes. This build is the strongest against the fast-expo, given the travel distance is not too great for the zeals. Scouting and harassing is important here, and probes at the attack site are just as valuable as the zealots.

Build:
 * 8/9 – Pylon (near choke)
 * 9/17 – Gateway (scout, leave probe near enemy base)
 * 10/17 – Gateway
 * 11/17 – Zealot (hotkey, then rally gate to enemy choke, no probes)
 * 13/17 – Pylon, Zealot (hotkey, then rally other gate to enemy choke, no probes)
 * 15/25 – Zealot1, send 2nd probe to enemy choke

For pvz, make sure the scout probe stayed alive, it is needed to assist the zealots in killing the lings. Also make sure that if it is a fast expo situation, harass the drone(s) that comes out so it cannot place what will be a sunken. With the probe attacking with the zeals, lings die in 2 hits instead of 3. Setting hotkeys for the gates is important so you can focus on necessary micro at the enemy choke, instead of going back to the gates to queue more units. After the second pair of zealots, you can gas up and tech as normal (stargate or temp archive), or you can continue the pressure with zealots, looking to force more ling production and delaying economy and tech for the zerg.

In pvp, 9/10 will own a 1 gate-goon tech, even if he sticks a zealot in while the cyber core is warping. However, all you will have gained is an inferior economy if the enemy toss went double gate zealots as well.

1If you are brave, you can make the 2nd pylon in the enemy choke so you can build a battery to reinforce the rush. If the battery finishes warping and there are zeals left to heal (not always the case), it should spell the end for zerg.

²If you want, you can rally the nexus to the choke as well so other probes can get in on the action in case the original pair died. You have enough economy mining to execute this rush, however, once zerg solidifies his position, these probes should be sent back to mine.

Protoss 10/12 Gate Zeal Build
Matchups: Pvz, Pvp, Multiplayer

Theory: This is the most popular and simple zeal build for protoss, because it sacrifices no economy besides the standard scout probe. While not as fast as the 9/10 rush, it is serviceable for a variety of situations, including multiplayer games. Room to solidify your position and tech hard is also granted (done easily by halting zeal production), and it still can yield a fairly decent rush against an unwary enemy.

Build:
 * 8/9 – Pylon (scout if enemy went random)
 * 10/17 – Gateway (scout if you have not already)
 * 12/17 – Gateway (11/17 if you scouted late)
 * 13/17 – Zealot, Pylon (in that order, hotkey and rally gate to choke)
 * 17/25 – 2 Zealots, Pylon1 (in that order, hotkey and rally other gate to choke)

Here is where the build ends, because it depends on the situation what to do next (good scouting helps). If zerg got a decently fast pool, the three zeals can wall the ramp, and you can either tech hard by throwing up the assimilator and cyber core, or continue pumping zeals and rushing with a decent number of them (not to exceed around six, unless he is not teching either). The options from here are up to you, and it depends on how he opened.

1This pylon can be substituted with an assimilator for faster tech, however it will delay the rush somewhat if an opening appears to do so.

Protoss 10/12 Gate-Assim Build
Matchups: Pvp, Pvz, Multiplayer

Theory: This close cousin of the normal 10/12 gate is designed to allow gas collection while building up a force of zeals. An assim is substituted for the initial zealot in this case, and the drawback is that the rush will contain one less zealot. The economy that will be diverted into the assim is not needed to mine as you will have enough eco to support your mineral-based activities. The main advantage here is that you will have a substantial gas pileup by time your cyber core finishes, something that is helpful for the midgame. In Pvp you will have enough gas to get legs and robo tech, and in Pvz you will have plenty of gas for temp archive units. This is also a solid multiplayer build as well because of its flexibility and ability to switch to hard tech and then produce mid-tech units once those buildings complete.

Build:
 * 8/9 – Pylon (scout if random)
 * 10/17 – Gateway (scout if you have not already)
 * 12/17 – Gateway (11/17 if you scouted late)
 * 13/17 – Assimilator, Pylon (in that order, hotkey and rally gate to choke)
 * 17/25 – 2 Zealots, Pylon (in that order, hotkey and rally gate to choke)

Here gas collection has already begun, and now with good scouting an opportunity to rush may arrive. You can continue zealot production, or you can build a cyber core instead of a 2nd pair of zeals and tech as normal. You will find you will have at least 300 gas (usually a lot more) by time that core finishes, which really broadens your options compared to your normal gas amount when your cyber core warps in (200 at most).

Protoss Proxy-Gate Zeal Rush
Matchups: Pvz

Theory: This build is a do or die option, based on making medium distance trips much shorter by making the gateways halfway toward the base. This build works well when there is a large middle from which paths emerge going to each starting position (e.g. Lost Temple), as well as on two-player maps (e.g. Bifrost). Gates in both cases would be made in the middle of the map cutting the walking distance for zealots in half. However, if the zerg defends it, those gates are nearly impossible to hold with the threat of the lings running by it and into the undefended economy.

Build:
 * 6/9 – Send probe to middle of map or near enemy base
 * 8/9 – Pylon near midmap
 * 9/17 – Gateway
 * 10/17 – Gateway (scout)
 * 11/17 – Zealot (hotkey and rally gate to enemy choke, no probes)
 * 13/17 – 2 Zealots (hotkey and rally other gate to enemy choke, no probes)
 * 17/17 – Pylon near nexus, send 2nd probe to enemy choke.
 * 17/25 – 2 Zealots

If zerg went fast expo, that expo is as good as dead since this build is basically 9/10 gate on steroids. Make sure that you take some probes with the scout and zealot and harass plenty. If zerg went 9-pool, then this build dies. If things get hairy hold position at his ramp until reinforcements arrive. This is an all-out rush, and if it fails the game is just about lost for you.

Protoss Tech Build 1
Matchups: Pvp, Pvt, Pvz (no fast pool), Long distance between mains.

Theory: This build introduces fast tech on ground maps (assuming there is a ramp). It includes a fast zealot while the cyber core warps for rush defense (hold position with a couple probes on ramp). It is an introductory build that will allow you to go up any tree. It can be done in any matchup, however you will have trouble with fast pool zergs.

Build:
 * 8/9 - Pylon (Scout, preferably at choke in case of random zerg)
 * 10/17 - Gateway
 * 12/17 - Assimilator
 * 14/17 - Cyber Core
 * 15/17 - Pylon, Zealot1 (hold probe production momentarily so you can get a pylon in there first)
 * 17/25 - Dragoon, Gateway

1Necessary to hold quick lings in Pvz and 2 gate zeals in Pvp.

From here you can add a gate and begin amassing goons, or you can add citadel tech (then gate), or you may elect to go robo or stargate right away. This is a very flexible starting build, and if the zealot lacks a purpose after a while (assuming he did not rush) then it will make an excellent scout.

Protoss Tech Build 2
Matchups: Air, Hybrid, Pvp, Pvt

Theory: This build introduces fast tech on air and hybrid maps. It can also be done in Pvp and Pvt ground games. It is an introductory build that will allow you to go up any tree.

Build:
 * 8/9 - Pylon (Scout, preferably at choke in case of random zerg)
 * 10/17 - Gateway
 * 12/17 - Assimilator
 * 14/17 - Cyber Core
 * 15/17 - Pylon
 * 17/25 - Dragoon1 (ground maps)

From here you can add a gate and start massing goons (for ground maps), or you can continue up the robo or stargate trees on air/hybrid games. On non-ground, robo is preferred and is good for random. Stargate is exclusive for zerg.

1Against zerg a second zealot is better. If you are going to do a furnace (pvt strategy for fast back door drops) start a robo right away.

Protoss Tech Build 3
Matchups: Air, Hybrid

Theory: This build introduces fast tech on air and hybrid maps. It varies from tech builds 1 and 2 since here the assimilator is made first and then the gateway after. It has features that will allow for more aggressive teching once the slightly slower cyber core finishes.

Build:
 * 8/9 - Pylon
 * 9/9 - Assimilator
 * 11/17 - Gateway
 * 13/17 - Cyber Core
 * 15/17 - Pylon

In this build when the core finishes, you have the added choices among the normal plans to go double robotics (Pvp, Pvt) and double stargates (Pvz). The extra gas will also allow a fast +1 air that will finish long before goon range is needed.

Protoss Fast Expo Build
Matchups: Pvp, Pvt, Pvz (no fast pool), FFA, Average/long distance between mains

Theory: This build allows for a fast second nexus at your expansion. Depending on what the enemy is doing the build will differ after the nexus has begun warping in. However it does supply protoss with a tremendous economy after five minutes, however watch out for hard tech by the enemy.

Build:
 * 7/9 – Send probe to expansion
 * 8/9 – Pylon in choke (make sure not to block where the nexus will go)
 * 12/17 – Nexus (scout)

The build now diverges.

Pvt (mech build):
 * 13/17 – Gateway, Assimilator1
 * 14/17 – Pylon in main
 * 15/17 – Cyber Core
 * 18/25 – Robo Facility, Dragoon

Continuously scout the terran. You might need a forge to stop a vulture sneak. This build is risky when you have a cliff above the natural, since even though you will get your shuttle out early enough, he will have too many harass or push options. When your nexus finishes, do not Maynard too many probes (six at the most) so in case that expo comes under fire your economy does not suffer. You can always send extra later on when it becomes secure. Make sure you get warp pylons earlier than in other builds since you will have two nexuses pumping probes.

1If an SCV gets in the base before the gateway is laid down, run to your geyser and warp an assimilator before he can build a refinery on it.

Pvp:
 * 13/17 – Gateway, Gateway²
 * 14/17 – Pylon
 * 15/17 – Zealot, Assimilator (if not built already)

Watch out once again for fast robo and either reaver drop or a turbonewbie if there is a cliff over your natural. You should have fast archive covered nicely since you have the pylon to make cannons down there. Make sure you get warp pylons earlier than in other builds since you will have two nexuses pumping probes.

²If the enemy toss went straight for goons, then make that second gateway an assimilator and rush up to goons as well. If he went zeal rush, then throw up a battery as soon as the first gateway finish next to your choke pylon, and gather some probes ready to defend with the zealot.

Pvz:
 * 13/17 – Forge
 * 14/17 – Cannon, Gateway³
 * 15/17 – Assimilator4, Pylon [b](in main)
 * 16/25 – Zealot
 * 17/25 – Cyber Core, Assimilator (in natural)
 * 21/25 – Stargate, Pylon (near main nexus)

You will need the stargate for the muta. Two stargates may be needed even. You will have the gas to get +1 air if you want. You will also ave the gas to go double robo or fast to archive, slapping down another 3 gates before the archives finishes. Make sure you get legs before starting the archive. You can do anything you want really (zeal-sair-reav or zeal-temp or dragoon-reav) just scout well to make cannons as necessary. Make sure you get warp pylons earlier than in other builds since you will have two nexuses pumping probes.

³Make a 2nd cannon if you scouted a mass ling attempt, you will need it. Make sure to space out both cannons and place them behind buildings so the lings do not have easy access to them. Hold your ramp so the lings do not try to sneak by and run into the main.

4Gateway goes here followed by assimilator and pylon if you made a 2nd cannon.

Photon Cannons
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
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.

Reavers
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.

Carriers
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 susceptible to the Zerg Defiler's Plague spell, which leaves them with nearly no hitpoints. Carriers are also vulnerable against ghosts due to being locked down and rendered useless, and to a lesser degree with an Arbiter's Stasis field.

Teching
The Protoss's tech is based on one structure- the cybernetics core. The cybernetics core allows for the production of all the three advanced tech trees. Of course, the first building is a pylon, followed by a gateway, more pylons, more gateways, etc. The forge is optional, but highly recommended, because it is needed for the photon cannon. The forge is often built early, unlike an engineering bay for terran, required for the ground-to-air missile turret.

After a cybernetics core, the executor has a choice of three trees- templar, air, or robotics. The choice, of course depends on the strategy your opponent is using. If you don't know the strategy, build a robotics facility, followed by observatory and sight range.

The templar tree has two uses- templar and speedlots. However, if this is early game, you can only choose one. (The leg enhancement upgrade is 150 gas and the archives is 200) The templar would be used to counter zerglings (dts, archons, and storm), hydralisks (storm), or mutalisk (storm or archons) for zerg. Evidently, storm is a must have against zerg. Against terran, this tree would be used to rush templar if they have no detection, but aside for anti- m&m, no other use. For protoss, there is not much use, unless going for a templar drop.

The robotics tree has three units for three uses, shuttle, observer, and reaver. Shuttles are used for drops, such as the reaver drop. Reavers are used in drops, or for bypassing defenses. Observes are for cloak detection and spying. VS zerg, shuttles are used for drops, but reavers are excellent sunken colony killers with the damage upgrade. They kill hydralisk in one scarab, and kill even masses of zerglings. Vs Terran, shuttles are used to counter tanks. Zealot bombs and reaver bombs are used to great effectiveness against tanks. Observers can make wraiths almost useless, and they can spot ghosts trying to spot for nukes. Vs protoss, reavers can be very effective in terms of stopping charges and blowing through shields and photon cannons. In general, use this tree for taking an island expo.e.g the shuttle.

The stargate tree is for air units, like corsairs and carriers. The stargate tree is, obviously, for getting combat air units. Against zerg, unless going overlord hunting, there really isn't much use. Against terran, however, it is important. Both the initial craft, scout and corsair, can be very effective against siege tank drops. Corsairs cast disruption web, while the scout destroys the tanks. Keep in mind that a smart tank commander would build missile turrets or bring marines/goliaths, so use the web and dragoons.