The Art of Mech: TvZ

This guide will cover most aspects in going mech for TvZ. Mech is one of the most powerful compositions anyone can ever go and if left untouched a 200/200 fully upgraded mech (with Vikings) army WILL destroy the Zerg, no doubt. The difficulty in going mech is that there are a lot of timings in which the Zerg can exploit in the mid game before you can get the deadly 200/200 army.

Mech is most effective in large maps where the rush distance is far and where it’s easy to take your 3rd base. Examples include Antiga Shipyard and Daybreak.

Pure mech

For starters I’ll show you the Pros and Cons of going mech;
Pros:
- One of the deadliest compositions when maxed, most other compositions cannot fight it head on due to its sheer DPS.
- Takes relatively less APM/micro compared to Marine/Tank or MMM.
- Cost efficient, once you get enough tanks in the early mid game it is very hard for Zerg to break you especially if you tailor your sim city to block off attack paths.
- Hellions are very good for harassing, especially so after you research blue flame.

Cons:
- Vulnerable to early pressure and can kill you if you are not prepared.
- Requires good decision making, one wrong move (e.g. move out before having enough tanks, not harassing enough etc.) can cause a gg from you.
- Relatively slower than MMM / Marine Tank, this slow mobility gives Zerg more time if you do go decide to attack.
-Very gas-heavy thus requiring you to take more bases earlier than you are used to.

Before we start be warned that going mech means going macro. Meaning there are not really a ‘timing’ in which you can aim to kill the Zerg. Mech is designed to kill at around 180-200 food so be patient and be prepared to play a long game.

Key Units:
- Hellion - used for harassment and counter attacks since it is the only unit that has a high mobility in this composition.
- Siege Tank - the real damage dealer, but with its relatively low health make sure to use your hellions / Thor to tank the damage in the frontlines.
- Thor - used for anti-air and is very effective for tanking damage from banelings.
-Vikings - needed only when you know Broodlords are coming and is a very robust anti-air.

I recommend going for the Cloaked Banshee / Hellion after Expand as an opening since this build has been proven time and time again to be very effective. It was also used a number of times during IEM that happened very recently. Remember that this is not the only build you can do before transitioning into mech.

Basic BO:

-10 depot
-12 barracks
-15 orbital
-When 1st Marine out, build CC in-base / natural
-After your orbital is complete, 1 scv, double gas
[email protected] gas, factory
[email protected] gas, reactor on barracks, swap over to factory
-Build two hellions and then supply depot. This is important as hellions take 2 supply and you’re going double each time
-When factory is done build starport. Use barracks to build a tech lab for starport
-When starport is done move tech lab; research cloak first, then banshee
-When you have the money (around 8 minutes), build a third CC
-Double gas at natural
-Around 8:30 build two Factories and an Armory. Build tech labs on both and then produce 2 thors, since a fast muta transition can really catch you off guard

2 Thors just before Mutas pop out

Now of course you can change this BO as you wish, depending on what you scout (e.g. if he’s going very aggressive etc.). This is just to give a general sense in how you should carry out the hellion / banshee build.

Early Pressure from the Zerg

As I said early pressure can kill you if you are not prepared so here is a quick list of the types of pressure Zergs can apply to you. Scouting is key here. Do not skimp on your first scouting SCV and do scout around the 5-6 minute to make sure you know his build. Key scouting include his drone count, how many gas he has mined and whether he has a lot of units early game (>4-6 lings).

The 7RR
- Early roaches after expand from the Zerg. This can be hard to hold but with your early hellions you should scout this. Build a bunker and start producing marines and tanks, hold off banshee production after the first banshee. This should be enough to hold off the aggression especially if you have your 2nd CC in-base.

Baneling Bust
- Your build counters this. Stall as much as possible with your hellions, build a bunker and you will hold it off easily as long as you don’t lose your first hellions.

Roach/Ling/Bling
- This is the most dangerous aggression in my opinion. Get siege tanks immediately (before banshee) as soon as you know this is coming. Build a bunker and have supply depots in front of it so that lings will not be able to reach it. Lift up your 2nd CC if need be. Also don’t be afraid to pull SCVs.

Simcity

- Walling off your main is essential (with supply depots and/or your first Barracks) to prevent ling runbys since this can be frustrating to deal with, especially late game.
- Create a supply depot wall in your ‘frontline’ i.e just in front of where your army is camped near your bases.
- Your production facilities should be laid out carefully, I could not count how many times I’ve lost due to the simple fact that I mistakenly blocked off paths out of my base and thus having 5+ tanks stuck in my base.
- When expanding after your 2nd base start creating Planetaries, even additional ones in locations where a Zerg may counterattack is a good idea when the game is approaching late game (e.g. in Metalopolis you should create Planetaries to cover the 2 attack paths near the Xel’Naga Towers).

The proper way to wall off

The Mid Game

This is where mech starts to shine. Positioning is important here. So siege your tanks in key places and do not siege them all in the same place. For example in Antiga Shipyard you should place a few on the very edge of your base which overlooks the path towards your natural and third base. Have your Thors in the frontline to tanks damage when you are aggressive.

Positioning

Harassing in this stage is also very important. The only way to keep Zerg in check without them expanding like crazy is to harass with your hellions. 3 hellions can roast drones in one shot and that is before the Blue Flame upgrade. Having packs of 4 hellions harassing the Zerg constantly will surely scare them into making defensive Roaches and and keep them at bay. Do not be afraid of losing them, it is better to sack your 4 hellions and take a chance to kill drones since they are cheap and easily replaceable with Reactor’d Factories. Also you can produce a few Medivacs to transport hellions to their bases faster.

Build turret rings on the side of ALL your bases and build Sensor towers in key locations so that Zerg will not surprise you with Mutalisk harass and Nydus plays.

Turret rings

You should tailor your composition to the Zerg’s response to mech. A mutalisk based Zerg can be a serious threat if not dealt with carefully (use Sensor towers!). A Zerg rushing to the ultimate Zerg army (Infestor / Brood Lord / Corruptor) can also be a threat, be sure to keep scouting and prepare anti-air (more Vikings / Thors) as you see fit.

The Late Game

Once you reach this stage resources (especially gas) will become much more important since they are scarcer. Cut back on harassment and always focus on building your mech army (including Vikings) with less hellions and more anti air (Thors).

Build Command Centers. A LOT of them. Since mech is gas intensive you will always have excessive minerals. Sack SCVs but save some for your army (for repair). Scan will also become more important for scouting hidden bases, tech switches etc. without sacrificing a few units since scans are ‘free’.

Brood Lords are a serious threat. It may be easy to over produce Tanks. I’ve done this myself, barraging to the Zerg’s natural only to be decimated with a Brood Lord switch that I have dismissed. Always have a Raven and a few Vikings in your composition even if you do not scout any air from them since Zerg can always tech switch very easily.

As the game goes longer you may decide to transition to Sky Terran. This composition is not explored extensively yet and this is why you should be very careful transitioning and not get caught off guard. Remember the longer the game goes on the more valuable units with energy are (Ravens and Battlecruisers).

Quick tips and suggestions

- Have several SCVs in your main army to repair your mech and to keep them at top health.
- Do not be afraid to lost hellions, they are expendable.
- Have Planetaries when you take additional bases after your natural.
- Build Planetaries in key locations where Zerg may counterattack.
- Scout extensively. As shown above Zerg can do a variety of aggressive play and you need to be aware of which one he's going for. 

As always thanks for reading,
GL HF!