[G] TvP Mech in SC2 - An Introduction

With the popularity of bio play in these first few weeks of beta, people have been reluctant to use mech openings. There is good reason behind that reluctance.

-Bio is much stronger early, so you can be aggressive off the bat.
-Bio is very strong with almost no micro needed, and you can 1a2a3a (or just 1a cause unlimited selection =P) into a toss army and come out on top.
-Bio does not often require good scouting/preparation/defense as it is universally strong
-Bio is more mobile so you don't need to worry about being caught with your pants down
-Lastly, bio uses low tech units which can get early, so you get to do things with your army as soon as you want which is fun

These are all great qualities of bio play, but there are downsides as well:

-Bio deals lots of low damage with many units, so armor dramatically reduces its damage output
-Bio is very vulnerable to splash damage
-Bio does not deal splash damage, so it scales linearly with force sizes
-Bio clumps big time, so splash damage is impossible to avoid except in very open areas.

Now that we've examined the alternative, let us look at the point of this guide, mech. Lets start off with all the vulnerabilities of mech that bio does not have:

-Mech requires careful positioning and control
-Mech is weak early game with only a handful of units and is very micro/position dependent
-Mech is extremely gas heavy and takes longer to build up a sizable army

Now lets see what mech excels at:

-Mech units deal large amount of damage at once
-Mech units splash, and therefore scale exponentially with army size
-Mech units have siege capability (tanks/thors with particle)

Now that we've laid out the basis for bio vs mech, let us look at why mech is the best option. Bio play weakens as the game progresses. Some may say that you can simply transition into mech, but then all the money spent on bio upgrades/production/research is completely wasted. If you do not do substantial damage with bio in the early stages or gain some sort of advantage, you are putting yourself at a disadvantage as you enter midgame/lategame.

Going with a pure mech approach allows you to do 2 things. First, you can focus on 1 production building, the factory, which serves you all game, not just the first 10 minutes. Second, you can move into midgame with a stronger army that already has some upgrades.

The skeptic right now is thinking, "you're just going to die to an early push with mech, or get out expanded because mech is super weak early." However, I can assure you that proper mech play negates both of these concerns.

The early game:
The early build order for mech is pretty much the same for all variations. First, you get your depot, then a barracks, then your first gas. At this point, just like in starcraft 1, you have to make a decision. Is my goal to secure an early expansion, or to make more production buildings? For the former you only need 1 gas until after your factory has completed and your CC started. For the latter, you want to add that 2nd gas fairly soon, so you have enough money for units/research and more production buildings. As with most builds, build scvs constantly to get your economy going.

There are 3 builds I have been using earlygame. These are as follows:

1 Fact FE:
Pretty much an exact duplicate of the sc1 siege expand. Make 4 or so marines, a factory, then expand under cover of siege tanks. The difference is gas, since sc2 has a different gas system. I stay on 1 gas til I have my CC started then I'll add the 2nd gas in my main. Siege often comes a little later than the sc1 build, but that's ok, because there are no ranged goons anymore that cause you such pains earlygame.

Make sure to add an ebay and place turrets as to protect your main/ramp/nat. Turrets will keep collosi away, drops away, and help deal with dts. The best part is they kill observers, and a blind protoss is a scared protoss.

If you scout protoss doing something outrageously aggressive, it may be wise to either take a macro loss and upgrade to a planetary fortress as soon as you land your cc and/or make a bunker or two to protect your expansion. Bunkers are your first choice, PF second. It is unlikely toss will go allin and try to break your expansion, but if he does, make sure your tanks are back, preferably in siege, so that immortals can't hit them from below, and that you have a couple tanks in your natural behind your bunker so that if he wants to attack them the bunker will fire on his units. Bunker fire will wreck immortal shields so you should have no issues holding.

Fact/Port
This build is designed to get an early helion drop into the toss minline and do maximum economic damage, plus scare him into playing defensive/punish him if he plays aggressive. Helions are like vultures + firebats. They are super fast and deal line splash damage and have an upgrade for double damage to light. Helions are a probe's worst nightmare, and this build is designed to capitalize on that.

Build a couple marines as is needed to stave off early aggression. Make sure you have your 2nd gas early. As soon as your factory completes lay down a tech lab (unless you're facing some serious zealot pressure where marines are going to have an issue, then make a helion first). Add a starport immediately. When your tech lab completes make helions and research ignitors for +10 to light. As soon as your port completes make a medivac (isn't it great that you don't need an addon for dropships now?). You should have 3 helions when you load up. You can wait for a 4th helion if you desire, but keep in mind the longer you wait the greater chance the protoss player will scout your build or have enough units to negate it. Drop helions in the back of his base and proceed to rape probes at will.

To transition, start making siege tanks and expand very similarly to the 1 Fact FE; However, you are expanding later to do some aggression early. I've had a lot of success with this build and it really catches protoss players off guard. I especially like it when they click on a mineral patch in their natural to transfer so all the probes line up for me =D

2 Fact Aggression
This build is designed to do heavy damage to an expanding protoss. It is also the safest build vs any 1 base toss play, since you have the most units and only 1 base to defend. For this build get a 2nd gas as you would for Fact/Port. Instead of a port, lay down a second factory when you have the resources. Your first factory will have a tech lab and will be producing tanks. Your second factory will be producing helions with a reactor. I like to get about 8 marines with this build, since you want to have enough to burn immortal shields early and kill off air units, especially phase prisms.

Use your OC for scanning, not mules. You need to know exactly what the toss has, and when his expansion is coming up. You should have both siege and ignitors researched for your push, but if one is still researching that's ok, it will finish by the time you get to him. The push should be timed so his expansion is up and he has transferred probes, but he has not gained any additional income from it. I find leaving when the expansion is most of the way done is a good timing, but map distance is a major factor as well. When you begin your push, start making nothing but hellions.

The Midgame Push
So, either you’ve gotten your expansion up, or you’ve opted for a 2 factory push. How do you actually engage the enemy? Well pushing in sc2 is not that much different from sc1, with the major difference: no mines. Without mines you really have to SUPER careful about flanks and map position. The good news is that in direct confrontation your army is even stronger than in sc1, because your hellions do more damage to armored, and they do splash to everything. I like to keep in mind 3 important ideas when pushing:
-What is my push designed to do, why am I pushing?
-Where do I want my army to end up?
-What is the safest path from my base to where I want to be?

Once you have established these things, you can move out. The worst thing to do on a push is push without a plan. You will end up in a bad position not dealing pressure to your enemy and he’ll just crush you like a waffle cone. Don’t be waffly in your decision making.

So, you’ve managed to push across the map with minimal pressure, and you’re sitting right outside his natural choke, but you’re not quite in range of his base. What do you do? Siege up, lay down a couple turrets (always bring a couple scvs with your push). Keep your hellions between your tanks and his force. You can’t afford immortals and stalkers getting shots on the tanks, since they just do so much damage to them. Use your hellions and your front sieged tanks to inch forward. Continue making turrets and rotating your back tanks to the front. Eventually if he does not engage you, you’ll be taking free shots on his nexus/probes and he’ll be forced to engage. The entire point of rallying hellions is so by the time you are engaging you have a wall of hellions protecting your tanks. If you have any marines on this push, use them to snipe out immortal shields.

Now sometimes you may greatly outnumber his force right then and there if he’s being super greedy. If this is the case, just get your hellions in front and attack! Unsieged tanks still do great damage to stalkers, eat through immortal shields faster, and outrange protoss units. As long as you keep those tanks alive you should be able to steamroll the protoss on the spot.

What happens if the protoss has a really strong force and lots of immortals, perhaps supported by a colossus that really eats through that line of hellions? Usually you should be spotting the massing of immortals and lower gateway unit count. Naturally, the counter to high #’s of immortals is emp. If you are doing an early push you might not have the gas for emp, but if you are doing a later push you should have that ghost academy up and at least 1 ghost with your army. EMP the immortals and then he won’t be able to approach your tankline. Focus fire on colossi if you can, they drop really fast to tanks and are a huge investment (like reavers were) for the protoss.

Adjusting your build
Lastly, I will talk a bit about adjusting your build based upon what you scout and what your midgame plan is. Because mech is gas heavy, you do NOT need to spend all your OC energy on mules. It is much more important to have reliable scouting information. Scan frequently, use hellions to poke around the map, send scvs out. You do not have the luxury of an army which is universally strong so you MUST be aware of what he is doing. I will list some of the things I have seen so far and things I’ve done to deal with them. These are not necessarily the best counters and best adjustments, but they have had success. As I, and others, play more games, we will see with greater clarity how to adjust our strategies to account for varying style of protoss play.

-2+ Gate Zealot: This build is a joke vs mech. Terran can wall off, repair early, and either use a hellion drop or even straight up hellions to dismantle zealots without being hurt. On some maps like Lost Temple, it is very easy to wall off your natural as well. You can use this to your advantage to secure a safe expansion while keeping him from expanding until he gets enough to deal with your hellions.

-Early Stargate/Voidray: First, it should be easy enough to hold off single voidrays with a handful of marines. If he does some super cheesy fast voidray since he sees you teching, you should have no problem killing it off. Feel free to pump more marines. As the game progresses you really want a nice turret ring around your main and natural so he has to engage turrets to attack anything else. Turrets are very strong and repairable, and incredibly cost effective vs voids. As you move into midgame you have 2 strong options. Lay down an armory and make thors. You’d think thors are weak vs voidrays because they are massive single targets for voids to charge up on, but they have insane GtA range and do a ton of damage to multiple targets. A few of these puppies and voidrays won’t want to get close. Thors also are built from the factory, rape ground, and have particle cannon, so you can’t go wrong with them. The other option is Vikings. Vikings require a starport to make, but 1 starport with a reactor can produce quite a few Vikings. Vikings are very mobile, unlike the clunky thor, and are easily microable, and do a TON of damage to air units. Not only that, but if the enemy transitions into carriers or mothership, having Vikings around will punish his bad decision. Vikings also are excellent support for killing immortals and colossi, and hold their own vs zealots and stalkers. They are not the most cost effective choice vs ground, but they aren’t useless.

-Zealot/Immortal/Collosus: No stalkers means no AA. You really can’t push out vs a force like this, because it is the strongest GtG force protoss can put together, but you shouldn’t have to. Banshees will be able to do whatever they want, including pick off all his power units, which will open up a window for you to push. Vikings can run around and cause mayhem as well. However, both of these options require starports which take time and money to make. Ghosts are essential vs the high immortal count and they do good damage to zealots as well. Ultimately, this kind of protoss army loses power as army sizes grow, so you’re best off just camping and trying to squeak in a 3rd while harassing with starport units. Eventually the protoss will be forced to either make stalkers or fall behind because he can’t deal with your air control.

-Carriers: Carriers suck for terran. I can’t even begin to describe how annoying it is to have an army with maybe 1-2 thors vs 6+ carriers. The importance is to scout. If you see a really low gateway count and small gateway army, but you haven’t been dealing with voidrays, he’s hidden stargates somewhere! Scout for them and push asap! You need to do damage while you still can. If in fact you can’t really push, start pumping thors from all factories with tech labs and add starports en masse. Vikings are very strong vs carriers but you won’t likely have many to begin with, so you need to catch up to him very fast. Reactors on all starports and you should be able to produce enough Vikings in time to shut down his carriers. This is the #1 most annoying thing I’ve encountered. It is also a real problem in sc1 for TvP, so this isn’t news. It does not mean carriers “counter” mech. It just simply means you need to be aware that he is in fact going carriers so you can respond appropriately.

-Mothership: Make sure you have energy for scans, and hopefully you can take down his ground army before his mothership has enough energy for vortex. If you have ghosts, use that emp on the mothership. Making a raven or two at this point in the game is not a bad idea. I view the mothership, especially after the patch, as a ridiculously annoying arbiter. It however will go down quite fast to thors and Vikings. I haven’t played vs motherships very often, but I believe they are the best way to manage a mech army (just as arbiters were in sc1) for protoss. The important thing to do is not panic, because the mothership doesn’t do anything on its own, especially if you emp it.

-DTs: Pretty much are just annoying if handled correctly. Good turret placement and saving energy for scans will make them useless. However, they are much more difficult to see than in sc1 I feel, or at least for my untrained eye. They go down ridiculously fast to tanks, hellions, ghosts, and basically anything that’s not an scv or marine. They pack a punch, so don’t accidently overlook one beating on your force in a battle. It’s very easy to not notice them (it’s happened to me) and they will eat your force alive. Just make sure you are saving energy for scans and turret appropriately and they shouldn’t be a problem.

There are many things which I haven’t really discussed here, but the fact is that in the few weeks beta has been out there hasn’t actually been enough time to encounter all the possibilities. As more things arise and more games are played terran players will know better how to react to these things. If you feel something is left out here, by all means ask me to add it! I can’t play 50 games a day, so I’m not going to see everything out there.

Parting thoughts
Hopefully now you have a rudimentary understanding of how to execute mech play. There is only so much a guide can say without a very solid metagame to build on. As people in starcraft 2 learn more about what works and what doesn’t, guides can be much more detailed and specific. For now, a lot of play will fall back on the basics (macro, scouting, micro) and less on deep strategy. Improvisation is a huge part of starcraft in general, so don’t worry if you run into a situation this guide doesn’t cover, because it almost certainly will occur. Just improvise. If it works, great! If it fails, you now know how to not react and can share that experience with everyone else.

This guide does not talk about lategame play with mech builds. The primary reason for this is because I have played so few games that extend into lategame. Most games are still ending quite early. As longer games are played I can come back and add a section regarding lategame play to this guide, but more likely specific mech strategies will have emerged, and introductory guides like this one will no longer be heavily used.

I hope that this was a thoroughly educational read for you. Now go out there and kick some protoss ass!