Guide detailing Zerg upgrades vs Terran

By a 6 year SC1 Veteran

Hi there, it's me again. As promised, here is my write-up about Zerg ground upgrades vs Terran.

If you haven't actually read the ZvP upgrades, I strongly suggest you to do so now.  Just look through the Guides section.  Just like last time, I am going to leave out the heavy number crunching, as it really isn't the important "take home" message I am trying to convey. As usual, I've highlighted the numbers, but I do suggest you read through the entire article.

I've noticed in some of the games I've watched, the Zerg sometimes gets Level 1 missile attack before Level 1 Carapace against the Terran.  In this write-up, I will try and explain the details of upgrading, and hopefully by the end I will have convinced you of the best method to go about upgrading.

Let's look at Level 1 melee attack first:

vs.

A marine takes 6 shots to kill a Zergling.  With +1 armor, the Zergling would be able to take 8 shots before dying.  This is a big deal, considering how quickly zerglings attack, and how many are produced.  Reapers (4 dmg x2, +5 against light) can take out lings with 2 hits.  The +1 armor allows the Zergling to take an additional hit before dying.  With that being said, the rest of the Terran army (Marauders, which kill a ling in 4 hits, Hellions, which kill a ling in 3, etc) would still kill a ling in the same number of hits despite the +1 armor upgrade.  Banelings, being quite similar to zerglings (5 HP less than lings), show similar benefits in the +1 armor: Being able to take an extra hit from a marine before dying (normally it takes 6 shots to kill a Baneling).  But that's the only benefit! The +1 armor only gives Zerglings an edge of marines and reapers, and Banelings only get an edge over marines.

So is it better to value the +1 melee attack upgrade?  A Zergling kills a Marine in 9 hits.  This is only improved to 8 hits with the +1 attack.  Roughly speaking, the benefit of being able to take 2 extra hits, is better than not having to deal one extra attack.  On the rest of the field, however, the +1 attack might look beneficial: Zerglings normally need a whopping 32 hits to kill a Marauder, but this is improved to 25 with the +1 attack.  A hellion can take 23 hits from zerglings before it dies, but only 18 from a +1 attack zergling.  Against the rest of the Terran army (tanks, reapers, ghosts, thors) there also seems to be significant gain.  But generally zerglings melt quickly to these units, so I rarely take these into consideration.

What about Banelings then? 2 banelings can kill a marine.  There is no difference with the +1 attack upgrade.  In fact, the only real benefit comes from Banelings vs. Marauders (normally takes 7 hits): being able to kill them with 6 hits.  So yet again, similar to BW, it seems the +1 carapace upgrade is largely favored over the +1 attack upgrade, seeing as only one unit (the zergling) would show any benefit from it.

But what about Level 1 Missile Attack?

Back in BW, a Zerg would upgrade +1 carapace, and then +1 melee. Lurkers didn't generally need a lot of extra attack power, and the +1 melee would help lings and eventually help the Ultralisks in late game.  But we're not worried about Ultralisks (I'll discuss Ultras at the end).  Since we no longer have lurks to contain the terran, or to defend our expansions, we need to worry about the mid game terran, and how our ling/roach/hydra army will be able to hold.  This is why I believe in SC2, missile attack is worth more than melee attack.

Let's look at Roaches first: A Roach can kill a marine in 3 hits and a hellion in 6 hits, with no change against both, despite +1 missile attack.  Against Marauders (9 shots to kill), Reapers (4 shots to kill), and Ghosts (7 shots to kill), the Roach can kill with one less hit for each.  Note: it takes a Roach 4 shots to kill the +10 HP shield Marine, no change with +1 attack.  So clearly, +1 missile attack has a few more benefits for the Roach then +1 melee does for the Zergling. 

Now let's not forget about the Hydralisk.  The Zerg's mid game army will generally consist of Roach/Hydra.  Hydralisks kill marines in 4 shots, which like the Roach, doesn't change with its +1 attack upgrade.  Against Marauders (12 shots to kill), Reapers (5 shots to kill), Ghosts and Hellions (both 9 shots to kill), the Hydralisk can kill with one less hit for each.  I've left Tanks and Thors out of both these equations, since they can take so much hits that any benefit (there still is a small benefit though) would be negligible in a real battle.  Against air (which really is the important part), Vikings and Banshees (which normally take 11 hits) can be silenced in 10.  Against Battlecruisers (62 hits, no joke!), a Hydralisk with +1 missile attack can kill it in 55 hits.

But if we're talking about the first upgrade of the game, our army wouldn't normally be dealing with too much air.  It's really the Terran ground army running around destroying expansions that we should worry about.  So we know +1 missile should come before +1 melee, but what's the priority of +1 carapace?

Level 1 Carapace

Let's look at the Roach again.  Marauders kill a Roach in 9 hits.  This does not change with the +1 armor.  However, against Marines (takes 37 hits), a Roach can take up to a whopping 49 hits!  Against Hellions (takes 25 hits), a +1 armor Roach can take 5 extra hits.  There is no change against Tanks (7 hits unsieged, 3 hits sieged) and Thors (2 hits).  Of course, there are benefits (huge benefits actually) against Reapers, Ghosts, Vikings and Banshees, but Roaches rarely deal with them.

How about the Hydralisk?  Its only against Reapers (6 hits), Ghosts (5 hits), Hellions (7 hits), and Tanks (7 unsieged, 2 sieged) that there is no benefit to the +1 armor.  But against the standard Terran bulk of Marines (16 hits) and Marauders (10 hits), the Hydralisk improves to 19 hits and 11 hits respectively with its +1 armor.

Though the +1 missile attack shows benefits in a wide range of areas for Roaches/Hydralisks, against a standard Terran Marine/Marauder army, the +1 armor allows the Zerg to defend its expansions with fewer units.  I think most Zergs overproduce their units in order to keep their expansions, which is why they would frequently be low on gas, unable to use other tech options (such as Nydus Networks or Infestors).  Therefore I truly believe that in a standard ZvT, when the Zerg is trying to defend its expansions, the +1 carapace (remember, there are benefits for lings too) takes priority over +1 missile attack. 

I think +1 missile attack is really for a timing attack done with a large mass of units, and in those cases after many battles, the Zerg frequently does not have enough units to defend its expansions against the replenished Terran army.  In those scenarios, if they are getting the +1 missile attack, why are they expanding so much? (I am referring to a specific game, ret vs Nazgul, see uploaded Replays, it's actually a great replay to watch) I think it is crucial for a Zerg to understand this point.

Of course, there are also other times when you would want to use +1 missile over +1 carapace, but that's only when you know your opponent is not going standard Marine/Marauder.  But honestly, against a Tank/Thor, or mass air units army, hypothetically you should be able to out produce them, or do an early rush that takes advantage of his early lack of barracks.

As promised, here are some stats on the smexy new Ultralisks: Marine needs to attack 121 times to kill, upgraded to 151 shots with +1 armor.  Marauders need 32 hits, upgraded to 34 with +1 armor.  Hellions need 86 hits, upgraded to 101 hits.  Tanks in sieged mode can kill in 11 hits, regardless of armor, and normal Tanks kill in 26 shots, only needing one additional shot after the +1 armor upgrade. Thors kill in 7 shots, regardless.  Ultras kill marines/reapers in 3 attacks, regardless.  Marauders die in 8 hits, improved only to 7 hits with +1 melee.  Tanks fall in 9 hits (8 with +1), and Thors fall in 24 hits (22 with +1).  Honestly, the +1 melee upgrade does not seem to help the Ultralisk too much; by that time the Ultras are probably already doing a shitload.

Now, I'm not discussing Level 2 and higher upgrades, because you will most likely never come across a decent Terran that has 0 upgrades the entire time.  Remember, any benefit you gain from Level 1 upgrades, are balanced when the Terran also gets Level 1.  The benefit is brought back, however, when you get Level 2 before they do.  Always be ahead in upgrades! Your research facility only costs 75 minerals!  I hope I don't need to say this, but try balancing your upgrades.  Don't rush to +3 armor just to get the benefits.

ZvZ Guide soon to come :)