Mech Build against Zerg

A great build for Terran against the Zerg race is a mechanized build.  Siege Tanks, and especially Thors are powerful against the Zerg.  Hellions also do a great job of harassment since Zerg players have a harder time of walling off the entrance points to their bases.  In this section a standard build order against the Zerg will be explained in detail.  At the end of the detailed breakdown, there will be a “quick reference list” for you to follow along quickly during your first few games using this build.  It is important to always remember that everything in Starcraft 2 has a hard counter, so always stay on top of scouting and ensure your opponent will not be throwing you any surprises.  If you see your opponent specifically countering what you are doing, be ready to diversify your army and transition into another build.

Getting Started:  Standard opening up to your first Barracks and Facotry.

When the game starts, the first thing you should do is start building an SCV out of your Command Center, and then immediately move all of your SCVs to mine minerals.  If you are fast enough, try splitting your SCVs and sending 3 to one mineral node, and 3 to another.  By doing that they will split faster between six different mineral nodes than if you had of commanded all 6 to go to one and let them automatically split up from there.

Now hotkey your Command Center to a number you feel comfortable with (hold down Control and press a number).  Build another SCV as soon as you are able.  Keep building SCVs for the next couple moments.  Watch your supply count at the top right corner of the screen.  When you are at 9, get ready to make another action.  The second your supply counter hits 10, grab that SCV that just spawned from your Command Center (this is technically your 9^th SCV as your 10^th is currently being made), move it to the ramp of your base and build a supply depot as soon as you are able.  The timing should work out perfectly that you can throw that supply depot down right away.  Note that walling off your base is important against a Zerg player to prevent Zerglings from running in and surrounding your marines early on, and to prevent the Zerglings from reaching your mineral line and destroying your precious SCVs.

Queue up another SCV while your Supply Depot is being built.  Once your 11^th SCV is made, you will not be able to make more until the Supply Depot finishes, so you do not need to worry about queuing up any more after your 11^th.  The second your Supply Depot finishes, using the same SCV that made it, build a Barracks right beside it.  The idea is to wall your ramp off using a Supply Depot (sometimes two are necessary) and the Barracks.  Be sure there is sufficient space to the right of your Barracks for an add-on to be made.  Not leaving enough space for an add-on will mean it will have to lift-off and move, and you will waste precious time.

While your Barracks is being built, queue up one SCV.  Then, once you have enough minerals, use one of your mining SCVs to build a Refinery.  Once the Refinery starts being built, just keep queuing SCVs with all your remaining minerals.  Your Refinery will complete before your Barracks.  Once it is complete, move two more SCVs from your mineral line to mine gas from the Refinery.  Keep queuing SCVs until your Barracks finishes.  Try to leave 50-150 minerals for when your Barracks completes.  The instant your Barracks is complete, produce one Marine from it.  Now send the SCV that made your Barracks out to scout your opponent.  Hotkey it so you can snap your view to it instantly once it arrives in your opponent’s base.  Set a rally point for your Barracks behind your wall but close enough to the ramp that it will be able to shoot any zerglings that attempt to attack or scout your base.

Note that a Drone scout might slip in before your wall gets up, and it might try to be a nuisance and attack the SCV making your Barracks.  If this happens, move an SCV off of your mineral line to attack the Drone.  This will prevent the Drone from killing your SCV on your Barracks.  If you have to, temporarily halt construction on your Barracks to move the injured SCV away and replace it with another undamaged one.  Try not to delay your Barracks if possible!

Now that your Barracks is complete and your scout is on it’s way, use an SCV from the mineral line to build another supply depot.  If your ramp will be walled once the Barrack’s add-on is made, build the supply depot somewhere around the perimeter of your base, so eventually you are viewing your entire base at all times.  If the add-on from the Barracks will not make a tight wall, then place your second supply depot at the ramp.  Also, keep queuing SCVs while your Marine and second supply depot are being built.

Once your marine is produced, throw down a Reactor Core add-on for your Barracks.  Since you started mining gas before the Barracks was even complete, you should easily be able to afford the 50 gas necessary to do this.  Stop queuing SCVs now and once you have 150 minerals upgrade your Command Center to an Orbital Command.  This is important to do early on because each Mule will bring in approximately 300 extra minerals.  Note that the reason you get your Marine before the add-on is for a couple reasons: 1) it gives you at least one unit to thwart away early Zergling pushes of 6 Zerglings at your ramp.  And 2) can be used to shoot at and hunt any Overlords that are scouting your base.

Now your scouting SCV should be in your opponent’s base.  What have you discovered?  Are they Fast Expanding?  Are they going to rush you?  Are they teching into a Lair for Hydras/Mutalisks or are they building a Roach Warren or Baneling Nest?  If they are preparing for a really early Zergling rush, or getting early Banelings to attempt to break down your wall, it may be beneficial to build a Bunker near your wall/ramp for extra defence.  Remember to repair it with SCVs if the Zerg player does attack unusually early.  If they never end up attacking, you can always salvage your Bunker later on and get your 100 minerals back.  If the Zerg player is Fast Expanding (most common), or teching up to Roaches/Hydras/Mutalisks, you can continue this build as normal.

After your Reactor Core finishes, once you have 100 gas, throw down your Factory right away (make sure you also have the 150 minerals required as well).  Once you throw down your Factory, build your second Refinery immediately.  Once that finishes, be sure to put 2 SCVs into it right away.  In the meantime use your Orbital Command to make Mules.  Never scan with your first 50 energy.  If your scout somehow fails at aquiring any information, send another one instead.  Always remember to keep building SCVs as it takes approximately 2-3 SCVs per mineral node for full saturation.  Even if you are fully saturating all mineral nodes, once you expand you can send your excess SCVs to your expansion to start mining right away.  Use any extra minerals while your factory is building to produce Marines and any needed Supply Depots.  Be careful not to Supply Block yourself.  Do not spend any gas while your factory is being built.  You are saving it up for a Siege Tank.

Once your Factory completes, build a Tech Lab add-on right away.  At this point you should have both of your refineries up and running with three SCVs mining from each, and a decent amount of SCVs mining minerals as well.  You should also have at least 3 Marines.

Once the Tech Lab has completed immediately start building your first Siege Tank.  Don’t forget to set a rally point for your Factory, preferably near your ramp.  Right after your Seige Tank begins production, research Siege Mode Upgrade from the Tech Lab as soon as you can.  Spend any extra minerals on Marines.  You should have extra minerals since you gain minerals much faster than gas.  Also, don’t forget to keep building SCVs and Supply Depots!

Once your first Siege Tank is complete, build a second one.  You should be able to queue your second Siege Tank right before your first one finishes, so that production begins immediately.  Keep spending excess minerals on Marines.

Timing Attack:

The instant your second Siege Tank is completed, now is the time to attack the Zerg player!  If timed right, your Siege Mode Upgrade should also be complete, or be complete by the time your army arrives at the Zerg Player’s base.  Usually at this stage, if they Fast Expanded they will only have a few Zerglings, maybe one or two Spine Crawlers.  Perhaps they will have a very small amount of Roaches.  If they teched to Hydralisks or Mutalisks they should have none, or very few out.  If they went for Banelings, keep your Siege Tanks in front of your marines as they can take a hammering of Banelings.

Group your Siege Tanks to a number you feel comfortable with, and group your Marines to a separate number.  Lower your Supply Depot(s) blocking your ramp and move your army out towards the Zerg Player’s base.  Always remember to raise your lowered Supply Depot back up so no Zerg units can sneak into your base!  While moving out across the map keep an eye on your army to make sure they are not being engaged.  Try to keep the Marines in front of the Tanks, unless your opponent went for Banelings, then keep the Siege Tanks in front.

Once you arrive at your opponent’s base (or perhaps their natural expansion), Siege Mode your Tanks before engaging the Zerg player’s army.  If possible, Siege them within range of the Hatchery, or any other building (such as Spine Crawlers).  Your tanks can outrange the Spine Crawlers, so if there are any, make sure you have Sieged up your tanks in range to attack them, but out of range of their attacks.  Keep your Marines really close to your Tanks to prevent Zerglings from getting a surround on your tanks.

Don’t forget to keep building at your base.  Once you start moving out, save up for a Command Center and start building that, inside your base if you like, where it will remain protected, and can then lift off after completion and fly to your natural expansion area.  Once the Command Center starts being build, spend all extra minerals and gas on more Tanks and Marines.  You will need these units in case your attack fails and the Zerg player chooses to counter attack, or in case your attack is somewhat succeeding and requires the reinforcements.

While attacking the Zerg player, if you do not think you have enough forces to destroy their Hatchery, target the workers instead.  Assuming you have disposed of their army (and they are now panicking and building tons of Zerglings/Roaches out of their larvae).  If they have an army, target it first.  Protect your Seige Tanks as best you can since they are the key factor in this early attack.  If all of your marines go down, prepare to unseige your tanks in case Zerglings try to run up for a surround.  If the attack is going poorly, you can always retreat back to your base.  It is always better to fall back if you are unsure, and save your units for a future attack/defence than to waste them and accomplish little!

After your Natural Expansion is up and running:

Once your Command Center has completed being built, if it is safe to do so, fly it to your Natural Expansion location and transfer some of your SCVs from your main base to mine minerals at your expansion.  Move your marines up to the Command Center since this is now where you will have to start defending from.  You may or may not have to move your siege tanks up depending on the map.  They may be better positioned on the high ground in your main base behind your ramp’s wall in Siege Mode.  Upgrade your Command Center into an Orbital Command so now you will have two Orbital Commands for twice the amount of Mules, or even Scans as necessary for occasional scouting.  It is a good idea to keep an SCV or Marine at any watchtowers throughout the map so you maintain a good field of vision of the map at all times.  It is also a good idea to occasional scout the gold high yield mineral locations if there are any, to ensure the Zerg player is not expanding further.

Once your expansion is up and running, build two more Factorys and an Armoury.  This will allow you to start making Thors.  Keep producing Marines, Supply Depots, and SCVs with your remaining minerals.  Also, be sure to build two more Refinerys at your expansion as soon as you are safely able to do so.

Since this point in the game can be considered mid-late stage, it is hard to continue giving exact build order instructions since many variable situations could have or currently be occurring, such as harassment, constant attacks against you, weird tech choices by the Zerg player, etc.  So here is an idea of some things you can build towards and always be sure to constantly scout the Zerg player to see when they are going to attack, when they are expanding again, and what units they are mainly building.

Thors are extremely effective against Mutalisks and fairly good against Hydralisks.  So you can safely produce a lot of Thors out of 3-5 Factories and mix in a few Marines to help with Zerglings and Roaches.  You can also always have a few Siege Tanks mixed in with your Thors, but mainly focusing on Thors at this point in the game is important.  Be sure to get their upgrade since it will allow you to quickly shoot down large units (like the ultralisk), or destroy Hatcheries and other buildings extremely quickly.  Also remember to upgrade weapons and armour at your Armoury!  Upgrades in Starcraft 2 are very important and you can win or lose fights sometimes just because of upgrades!

If the Zerg player is massing a lot of Infestors to counter your Thors (by mind controlling them in combat), try to focus fire them down.  Do not attack your own units unless absolutely necessary.  Killing the Infestor frees your unit.  You can also bring SCVs to your fights to repair the Thors during battle.  If your opponent goes for a heavy Roach build, they are fairly effective against Thors, so be sure to mix some marines in with your army to melt away those Roaches faster.

You can also get a Starport once you feel comfortable and get Vikings for Overlord hunting and try to Supply Cap your Zerg opponent.  Or you can get Ravens, upgrade the Hunter Seeker Missile ability which is incredibly effective against mass Hydralisks and mass Mutalisks.

When you need to expand again, it can be a good idea to go for the high yield gold mineral resources.  It is also a good idea to build a Planetary Fortress with your Command Center since two Orbital Command centers is sufficient for Mule/Scan production and the Planetary Fortress is very effective against Zerg ground units.  Try not to get out expanded by the Zerg.  If they are trying to constantly expand, either equally expand, or pressure them constantly with attacks.  If your Planetary Fortress is under attack, use all SCVs in the area to repair it at once, this will make it very difficult for ground units to destroy.  Also be sure to place turrets around your mineral line at all expansions since Planetary Fortresses cannot attack air, and Mutalisk harassment is fairly common.

If the Zerg player starts getting Broodlords try to focus them down with your Thors, rather than attacking the Broodlings.  Also, build Vikings as a very effective counter to the Broodlord.

Build Order Quick Reference:

• Build your first Supply Depot at 10 Supply Count, and wall off your ramp.
• Build your Barracks immediately after your first Supply Depot, also contributing towards walling off your ramp.
• Build a Refinery while your Barracks is being built.  Put two SCVs into it once it is complete for maximum gas mining.
• Build a Marine and another Supply Depot once your Barracks finishes.  Scout your opponent!
• Upgrade your Command Center to an Orbital Command
• Build a Reactor Core add-on for your Barracks once the first Marine is complete
• Build a Factory as soon as you have the gas
• Build your second Refinery, be sure to put two SCVs into it upon completion for maximum gas mining
• Keep building SCVs, Marines, and Supply Depots with excess minerals
• Build a Tech Lab add-on to your Factory once it is complete
• Build a Siege Tank as soon as your Tech Lab completes
• Research Siege Mode upgrade once your first Siege Tank is being built
• Queue a second Siege Tank up before your first one completes
• Push out once you have two Siege Tanks and a few Marines and the Siege Mode upgrade.  This is also a good time to start your first Expansion.
• Build two more Factorys and an Armoury to transition into Thors
• Upgrade vehicle weapons at your Armoury
• Attack with mass Thors and Marines, perhaps mix a couple Siege Tanks in as well
• Get a Starport and Vikings or Ravens (with Hunter Seeker Missile)
• Expand again once you feel comfortable.  Keep scouting your opponent and keep constant pressure.  Build a Planetary Fortress at your second expansion and beyond.

Good luck and have fun!