This begins the first of three race breakdowns, starting with the protagonist of Wings of Liberty, Terran. Terran are the best defensive race, having a number of options available to prevent a loss; they also have a few early game harassment methods open to them as well. They are essentially a balanced raced in these terms but have their own little unique features, such as a Mule from the Orbital Command Center, they can build anywhere and their buildings can fly around. They are the most versatile race in these terms.
As the game starts, Terrans can only build four buildings, a Command Centre to produce more SCVs, a Refinery to extract gas, an Engineering Bay to provide upgrades as well as research into other components and a Supply Depot to increase supply. Upon building a Supply Depot, the Barracks will become available to produce Marines, Marauders and Reapers. It also allows further research into Bunkers to hold troops, Orbital Commands to produce Mules, Sweeper Scans and Supply Depot upgrades, Ghost Academies for Ghosts and the Factory for Mechanical based units. The Engineering Bay allows research into Planetary Fortresses, Sensor Towers and Missile Turrets.
After building a Factory, this allows the player to build a Starport for all your aerial needs and an Armory which will provide upgrades for your Factory and Starport, it also gives you the introduction of the Thor. Finally the last building to be produced is the Fusion Core; this allows the player to build a Battlecruiser out of the Starport. One thing I’ve disused to add are the add-ons for the unit producing buildings, deciding to choose between a tech lab or reactor. A tech lab allows the player to build some of the higher end units, like Marauders, Banshees and Siege Tanks. However the Reactor allows the player to build two units at once, like Marines, Hellions and Medivacs.
The interesting thing about Terran, their initial unit, the Marine, is very versatile, doing damage to both ground and air units. With upgrades of Stimpack and Combat Shield, an army of mass Marine is quite interesting to watch, however easily countered by anything that does splash damage. Marauders are good against ground armoured units and benefit from Stimpack, as well as their own upgrade of Concussive Shell, which slows movement of an attacker when hit. They are easily countered by anything that can surround them, unlike the Reaper, very rarely do you see these come into play, which is quite a shame as they make a great harassment unit with their speed and ability to jump cliffs. They benefit from a speed upgrade but are susceptible to ranged units. Ghost are great for taking out anything with energy that may cause a hindrance in the late game, such as Infestors and High Templar. Using their EMP to remove all energy from these units, making them useless; they also are good for harassment using their nuclear strikes. Again like Reapers, don’t seem to do well against ranged units, assuming stealth doesn’t come into play.
Onto more mechanical units now, the Hellion is brilliant for early game, both harassment and scouting, they are incredibly quick and annoying to deal with but as before, are easily countered by ranged units. Siege Tanks don’t have a weakness per say, they deal high splash damage when in siege mode, but a well timed attack when moving into this state is advised, as well as use of air units. Thors are good against basic units, such as marines as well as clumped up air units, their upgrade is a deadly attack that deals mass damage over time. However with them being big heavy units with poor movement, are countered easily by Zerglings, also they’re armoured and countered by Immortals and Marauders.
Onto the final units, air units always seem to be an interesting development, perhaps stating intentions early with a banshee rush or just wanting to claim map control. Vikings are the first fighter unit you can create, these are good against air units, great against Void Rays, Corrupters and Battlecrusiers but lack the ground damage and seem to be ineffective against Marines and Stalkers. Medivacs are the linchpin of Terran play, healing biological units and also providing the option to drop units anywhere on the map. Drop harassment is annoying but if scouted early can be easily to counter. Ravens are great against stealth units, making them useless but are weak against most things that can shoot up as they have very little to counter. The Banshee with the upgrade of stealth is deadly for harassment, being able to shoot down rather than up, they make a good unit if undetected. Finally the Battlecruiser, brilliant against most things, they shoot both air and ground units and have an interesting upgrade, much like the Thor but dealing heavy damage to one unit.
Overall, Terran is the most balanced race in terms of producing units, but their macro is what excels the most. They have many brilliant openings to choose from, some long game mechanics as well as easy options to scout or harass. They make a great race to play when new to the game, this is due to the mass single player action you get with them. It is also why recently most tournaments have had a Terran being successful.