
Protoss
The Protoss are a sapient humanoid race native to Aiur. Their advanced technology complements and enhances their psionic mastery. The Protoss are known as a race of warriors, despite the fact they were not always at war. They trained incessantly for combat, however, and prior to the Great War, warred with the kalathi and "other types" of protoss.
Probe


Zealots are the most powerful of the basic starting units and are more expensive than the others. Being modestly outnumbered by marines or zerglings is not a major cause for concern given the quality of the zealot. Their high hit points and excellent base ground attack with normal-type damage ensure that they are useful until late in the game, and they are arguably the best breakthrough unit due to their low cost and lack of need for micromanagement compared to the unwieldy archons.
Zealots are one of the few small units that can withstand punishment from terran bunker-and-siege tank defenses, due to their high hit points and high movement speed.
Dragoon


High Templar are Protoss warriors that use powerful psionic powers to support other protoss forces.
High templar are support units with powerful abilities. They are not particularly durable and do not have an attack, not to mention their slow movement. Although high templar hover, they still activate spider mines. They are vulnerable to many units such as siege tanks and other powerful units. When two High Templar are merged, they create an Archon.
Archon

Dark Templar


The dark archon is a spellcaster with no regular attack, unlike the archon. Like the archon, it is well protected by shields but has few hit points underneath; it is vulnerable to the science vessel's EMP shockwave. It is neither biological nor mechanical, and is immune to many abilities, such as Lockdown and Spawn Broodling. It is also a hovering unit and does not trigger spider mines. Dark archons are created by merging two dark templar. Dark archons can use powerful spells such as Feedback, which can kill most small units immediately, Mind Control, which gives the player control over enemy units, and Maelstrom, which prevents all units in a 4 by 4 radius to atack.
Reaver
The reaver is a powerful beetle-like robot which has one of the most powerful units in the game. Reavers attack by firing scarabs, each costing 15 minerals each. Reavers have a decent sight range, and their attack can take out most units in one shot. Howver, their cooldown time is long and if they run out of scarabs during a battle, they are mostly helpless and will be destroyed very easily. Reavers are great for taking out clusters of small units and are a key unit in sieging an enemy's base.
Arbiter
The Arbiter is a high cost support unit. It relies on fairly high shield and hit point strength to survive, rather than its low powered direct attack. It has a passive cloaking field that cloaks all nearby friendly units, but not itself. Arbiters are great help in executing aerial attacks, due to their ability to cloak all friendly units around it. A popular strategy is to attach an Arbiter to a group of carriers and take the enemy by surprise.

The shuttle is a unit used to transport units over long distance or rough terrain. Shuttles are commonly used to transport reavers given the reavers' slow speed. One notable strategy is the "Reaver Drop", whereas a group of reavers and dragoons are transported by shuttle and attempt to land near an opponent's mineral and gas harvesting operation. The reavers quickly destroy workers while dragoons provide cover. Compared to the terran dropship and zerg overlord, the shuttle has superior acceleration and top speed once upgraded, but is not as durable. Its carrying capacity is also constricted by the large size of protoss combat units.

The scout is optimized for the anti-air role, being durable and having one of the most powerful air atack in the game. However, they cannot cloak and groups of small ground units can take the scout out fairly easily. Scouts aren't used in alarge groups very often because of the high cost that would be better used for other means.
Corsair

Carrier

Interceptor

Thats it for Protoss units. Coming up next: Zerg!