Welcome to Zul d'Are, the protoss training planet.. You will be entering into the first phase of your quest for Warrior Status, and it will do you well to listen to my every word. Open your mind and senses, and let the word of the Ancients enlighten you as well as kill everything around.

Philosophies

The Protoss are a race that depends on the power of their units, rather then mass numbers. Units in the Protoss army has great strengths, and few weaknesses, but they require more management compared to the other races.

Unlike the Terrans (with great defense), or the Zerg (with great offense), the Protoss are good attackers. Zealots and Reavers give them their offensive power, and the new Cannons and Shield batteries make up their formidable defense. However, all these advantages come with a price, and that is a high costs of Minerals and Gas for most of the units.

In the early game, the Protoss have probably the worst recon abilities of all the races, and this actually be a very big problem for them. Because the Protoss units costs so much, it is much harder for them to change strategies on the fly, and with poor recon, this can lead to a quick death. The Cannon has given them a very versatile defense structure, but at the same time can make you fell too secure with them. The last thing you want do as Protoss is die.

Overall, the Protoss are very powerful, but they must overcome some disadvantages early in the
game before they can really flourish.

Resources

The Protoss need a lot of resources to support all their powerful units. Luckily, they have the best worker units in the game: The Probe.

The Probe doesn't have the problem of the SCV and Drone when constructing a building. They simply start the warp, and then are free to perform other actions. This allows the Protoss to gather Minerals and Gas at very fast rate, not spending anytime sitting idle. This fact almost negates their high unit costs. Just make sure you always have your Probes doing something.

In the early game, the Protoss usually need to have more Probes on Minerals then Gas. This is because of the high costs of their Zealots, Pylons, Forge, Cannons, and other early games units/structures. However, its also a good idea with Protoss to start getting gas very early, and let it start saving up so you will have a large load of it stored up when you get to the units that need lots of gas.

Expansions

The Protoss tend to rely heavily on expansions, mainly due to their high unit costs. You will need at least 2 full time expansion to be able to pump out the amount of units you need from the mid-game on, so securing an expansion as Protoss is very critical.

Protoss do not have to expand as early as the other races, because their Probes are bringing in resources faster then the other races. Usually expanding after you first major attack works OK, but you have to be careful. The 400 Minerals for a new Nexus can hurt you really badly if you build it at a bad time

Luckily, the Protoss can have very good expansion protection. Cannons and a Reaver or Templar is usually enough to hold any expansion early. Just make sure your Cannons cover a large area of your Minerals and expansion buildings. On island maps, the above is all you will need to hold expansions, but on land maps, you will need to reinforce your expansions once they are found.

Units

Probe
The workers of the Protoss race. They are relatively weak compared to Terran SCV's, but the same as a Zerg Drone. Their biggest advantage is being able to continue mining after starting a Warp Gate. (A warp gate is one of those big blue ball's that turn into buildings that was warped in from Auir)

Zealots

Usually the main part of any Protoss attack group. Dealing out 16 base damage, 160 total hit points, and relative low cost, the Zealot is the best early game unit. And with upgrades, it remains one of the best units in the game through out all stages. The only real weakness is that it is a only a melee unit, so ranged units can take off quite a bit of damage to them before they get in range.

Dragoon
These "back from the dead" tanks are one of the few ranged attack units in the Protoss early game. Unfortunately, their slow firing rate, explosive damage, and bad AI movement make this a fairly weak unit

Reaver
A gigantic worm-like robot, that causes mass destruction to anything that gets in its way. Reavers are simply the most damaging unit in the Protoss army, and when used in conjunction with shuttles (flying transports) make up one of the best land attack units around. They do require more management then most units and are very slow moving, but it is well worth it for the power they hold. They must be refreshed with new scarabs (their homing weapon) all the time.

Observer
These little spy cameras provide the best mean of recon for the Protoss. Being permanently cloaked, these boys can fly over the battle field with little worry of being attacked. Just have to look out for Missile Turrets and Cannons (who can see cloaked units). By mid game, you should have more of these then you know what to do with (if you are not low on resources at the time, of course).

Templar
The wizards of the Protoss army. They have one of the best attack spells in the game in Psionic Storm, one of the trickiest spells is Hallucinate (making a realistic copy of a unit but the copy can't do damage), plus the ability to morph into the powerful Archon. Basically one of the most important units in any Protoss army, however their slow speed, and low hit points make them easy targets for any unit.

Archon
These almost God-like units present a formidable force in most any situation. With 30 normal damage, splash damage, decent range, land and air attacks and 360 total hit points, this boyspack quite a punch. However, they have probably the worst AI in Starcraft, so they actually require more management then you would expect. (they make a great combo with Templar Hallucinations because
of their hot points and imposing image).

Scout
These most powerful air-to-air attack unit in the game. Little can stand up to a fleet of Scouts when used correctly. Their high rate of fire allows them to stand up to even the mighty Battle Cruisers and Carriers. However, their Ground attack is mush weaker, and makes them very vulnerable to land based attacks from units like Hydralisks and Goliath's.

Carrier
Basically these are "Flying barracks" or Carriers, that pump out "Flying Marines" or Interceptors. While they are not as powerful as they seem to be, they are still very useful to the Protoss Army. In fact, they are the only current means the Protoss have for taking out Turrets and Cannons with minimal losses. Their biggest weakness is that by killing the Carrier, you kill all its Interceptors, so most enemies just concentrate all their fire power on the Carrier and ignore the Interceptors so try to keep the carrier as far away as possible but still in attack range.

Arbiter
These flying mages can not only provide valuable support to your forces, they can break an enemy defense. Their ability to cloak any unit around them can offer just the edge you need in battles, you just have to protect them very carefully. Stasis allows you to quickly render a large force useless, and Recall will allow you to instantly bring a large force to where you need it most. While these guys seemed under used, they are actually very useful if you can afford to get them.