StarCraft/Protoss mission 8: The Trial of Tassadar

Surviving the Early Game
You may have faced the Protoss multiple times throughout the singleplayer campaign (that is, if you've played the three campaigns in chronological order), but this mission really shows you their nasty side. The two enemy tribes are extremely aggressive, and will attack any and all of your bases with huge forces. Therefore, it's in your interest to build up defenses in your main base before you venture out. While you steadily increase the size of your Probe fleet (make around 2 per mineral patch as before; also, the distance from your Nexus to the Vespene Geyser is slightly farther than usual, so consider putting five Probes rather than four on gas), save enough resources to build Photon Cannons at each base entrance. In fact, you should try to have three Cannons on each side before you even build a Gateway (you start out with a Forge, so this basic building can wait for a bit). Also, take the Carrier that you start with and stock it with four Interceptors. You will eventually be able to build eight per Carrier, but not until you tech to the most advanced Protoss structure—the Fleet Beacon.

Placement of your defending troops should be intuitive by now. The Hyperion is of special note here—this souped-up Battlecruiser is pretty slow, but its powerful attacks can be effective in repelling the early attacks (do not hesitate to use the Yamato Cannon on incoming Reavers). Just make sure something else is taking damage, because you cannot repair any damage done to the Hyperion. Remember, Terran mechanical units don't have shields and only SCVs can repair them. 850 HP might sound like a lot, but enemy Protoss units can often kill Raynor before you know what's happening if you don't pay attention.

Once the money starts coming in, build two Gateways and start pumping equal numbers of Zealots and Dragoons. The map is rich in resource nodes that you will be conquering later (that is, unless you're following one of the alternate strategies), so you can tech relatively slowly. Keep building Photon Cannons: the nearby Furinax Tribe (purple) has a sizable number of Reavers, and you need a large network of Cannons to distract them while your units go in for the kill. Also, Ara Tribe (red) will periodically send large fleets of Carriers and Scouts to your main base. To defeat these, at least eight Cannons covering each other per entrance is necessary. Don't forget to build a few more in the area between your mineral patches and the geyser.

Pushing Past the Reavers
Unless you are going for a quick strike on the Stasis Cell, you will need two or three additional resource deposits. The Furinax Tribe base directly to the south is the closest, so make this your first target. As mentioned before, these guys have quite a few Reavers; you can obviously get past them with air units, but you don't want to wait that long to attack this base, or it will be mined out. The solution? Reavers of your own. Build a Robotics Facility and Support Bay, and then three or four Reavers. The enemy have more than this, but they won't be clumped together for focus firing like yours will be. Before you push, there are a few things you should do. First, prepare twelve Zealots and eight Dragoons (including Fenix). Also, have a Probe get out to the area outside the bottom corner of your base, and then build a Pylon plus four or so Photon Cannons (refer to screenshots for the location). This will not only help your defense later, but also deter attempts by the Furinax to strike while your force is assembling. Also, periodically take the Hyperion to the northern edge of their base, and make surgical strikes on their Reavers and Photon Cannons with the Yamato Cannon. This will weaken their forces while making your own Reavers that much more potent. Finally, make sure Scarab damage has been researched at the Robotics Support Bay.

When ready, take the aforementioned strike force plus the Carrier and head south (you can take Raynor if you want, but he tends to take undue damage). Lead with the Reavers and bomb their defenses. Enemy Reavers are your priority targets; remember, they have the same range as yours do, so it's a matter of whether you notice them fast enough to order two of your Reavers to shoot at it. The Carrier can also help protect your ground units from them, as Reavers tend to run away when fire upon by air units. The Zealots and Dragoons can move in either when the coast seems clear, or your Reavers fall in danger. Combat enemy Reavers with Zealots; Scarabs do Explosive damage, which means that the large Dragoons will take full damage but the smaller Zealots only take 50%. Still, three Scarabs and their splash damage will massacre groups of Zealots (it should normally be four, but enemy Reavers have the Scarab damage upgrade), so do try to take them out as quickly as possible. Once the lumbering behemoths are gone, the rest of the base should be easy pickings.