This article is meant to cover the issue of critical upgrades analysis as it is at the moment.
In the summary:
Critical Upgrades will be marked blue, and outlined, what exactly is affected.
Mandatory upgrades will be marked green, as the profits are so huge that it might change
Uncritical upgrades are in red to make easy to differ.
Current underlying Patch Data is 1.3.
Could this have gone differently?
A critical upgrade is damage or armor upgrade in the game that changes the amount of hits the units
takes to get killed by another unit.
First and foremost, I will, which common sense should cover, only research into typical matchups on
the battlefield, and concentrate on low upgrades.
Second, for Zerg, we calculate with the exact amount of hit points.
Second, for Zerg, we calculate with the exact amount of hit points + 1 for all units but Zerglings and
Banelings, due to the fact that the others in the most engagements have enough time to regenerate
1 hit points, as hit point regeneration is 1 per 3 seconds. This has its flaws, as Zerg Units regenerate
Hit points over time, but for this article it shall be stated that the unit receives the damage in such a
portion that regeneration does not come into play except the mentioned, and of course note that all
Zerg Units are Bionic, and Broodlings gain on upgrades.
Third, for Terran, Hellions always have Blue Flame Upgrade, and regarding Marines, we count them
with 45 Hit points all the time.
This covers unstimmed unshielded marines as well as stimmed shielded marines, which might be the
most common cases.
Fourth, Protoss Shield Armor is based 0, and +1 per upgrade for every unit, and no shield
regeneration will come into play, although I listed critical upgrade for the very specific use of +1
Shield Armor on Blink Stalkers with presumption that the Shields are supposed to take all damage
period. VoidRay will be counted uncharged, because that would become too much of a challenge and
doesn’t make much sense to analyze elsewise. On addition, I will only look at Armor and not Shield
Upgrade as it is too expensive to rush for. Also, Guardian Shield changes many setups obviously.
I General Analysis
First of all, all upgrades bonus are linear. But, there are cases where damage upgrades add more
than 1 damage per upgrade, in which they out scale their opponent’s armor upgrades. This case
occurred concentrated on Terran Mech, why consecutive upgrades here are crucial, as well as for
Protoss Robotics-based play.
Another thing to note, is that units with high firing rate like marines, Zerglings obviously profit most
from additional damage and suffer from additional armor, so in these play-styles, upgrades are very
crucial as well (GSL Side note: MarineKing is very strong on upgrading).
The next thing I wanted to note is upgrades on harassment:
I would group Banshees, Hellions, Zealots (in drops), Dark Templars and Mutalisks as main
harassment units with which you be lusting to decrease the amount of hits on a worker.
But as far as upgrades are concerned, only Mutalisks, and only in ZvZ and ZvP, change the amount of
hits per worker, from 5 to 4.
All the other units already kill the probes quite sharp, so they don’t profit from upgrades anymore
apart from higher overkill.
Banelings though kill probes and drones with 1 hit regardless of upgrades once they have +2
Upgrades, SCVs with +3.
II Matchup Analysis
In this matchup, the main units in the battle are Zerglings, Roaches, Hydras, Mutas and Corrupters
against Zealots, Sentries, Stalker, Immortals and Colossi.
So… we analyze the different setups with normal setup, damage or armor advantage and
Zerglings against Zealots, Sentry, Stalker, Immortal and Colossi changes from normally taking 3, 6, 4,
2 and 2 hits and needing 35, 18, 36, 70 and 80 hits to kill. With Upgrade advantages, these numbers
change to 3, 7, 4, 2, 2 taking and 29, 14, 29, 47 and 65 needing, and with Upgrade disadvantage, the
numbers are 2, 5, 4, 2 and 2 hits to die, and they need 9 more hits against Zealots, 7 against Stalkers,
4 against sentries and 17 against Immortals. (On a side note, on +2 against +1, Colossi need 1 shot to
kill Zerglings, and on +3, Armor gets irrelevant).
The same math for Roaches gives us 11, 29, 12, 3, 6 hits to take and 10, 6, 11, 24 and 22 hits needed.
On Upgrade advantage, the numbers become 13, 37, 13, 4, 6 hits to take, and 9, 5, 10, 22, 21 hits
needed, and on upgrade disadvantage, they become 10, 25, 11, 3, 5 hits taken and 11, 6, 11, 25 and
For Hydras, the math is the following: Taking 6, 13, 9, 5 and 3 shots, and needing 14, 7, 15, 28 and 31
on original setup. With Upgrade advantage, the Hydra takes 6, 16, 9, 5 and 3 respectively and needs
12, 7, 13, 27, 29 shots, and with Upgrade disadvantage, the numbers become taking 5, 12, 8, 4, 3
shots, and needing 15, 8, 15, 30 and 33 shots to kill.
So bottom line for Ground Upgrades on Zerg is, Attack Upgrades change almost every engagement,
and if going very range heavy, Carapace has huge impact as well.
For the Protoss, against Ling Heavy armies, Attack Upgrade might be nice in case you are Zealot
Sentry Heavy, against Roach heavy, Armor is really important while attack doesn’t change much
significantly, apart from Colossi killing Roaches faster.
Against Hydra heavy armies, armor doesn't change much, but attack upgrades change kill counts for
all Warpgate units.
Now, let’s take a glimpse on air. We will only look at Muta vs. Stalker, Sentries, and Corrupters
against Colossi and from Stalkers.
So for Mutas, its needing 19 hits for a Stalker and 10 hits for a sentry, with upgrade advantage, its 17
for Stalkers and 9 for sentries, with disadvantage its 21 and 11 for a sentry. To kill the Mutas, it takes
13 shots from stalkers and 21 hits from sentries. If carapace was researched, it takes 1 shots more for
a stalker and 4 more for sentries. With damage upgrades for Protoss, 11 shots for a stalker and 18
shots for sentries.
The Corrupter math says 19 shots for a colossus and 17 to be taken down by Stalker. On upgrade
advantage this is 17 shots to kill and 19 to be taken down, on Upgrade disadvantage it is still 19 shots
to kill and 16 taking.
So Mutas and Corrupters gain strongly from attack upgrade, as well as both upgrades for Protoss
I dodged on doing Corruption math though.
For this matchup, we concentrate on the typical Bio-Ball vs. Protoss-Ball scenario, on a side note I will
investigate a bit late-game Tanks, as this is the common way this matchup is evolving at this point in
The Infantry Armor shall be researched first: Marines get killed by Zealots, Stalkers, Sentries,
Immortals and Colossi in 3, 5, 8, 3 and 2 shots, after a Armor Upgrade, this changes to 4, 5, 9, 3 and 2,
which basically means, the upgrades mainly affects Zealots and Sentries. For the Marauder, an Armor
Upgrade changes their durability from 9, 10, 25, 3, 5 to 11, 11, 32, 3, and 5. For the thesis for Marines
can be extended to Gateway Units in General.
In the Attack Department, math gets a bit rough because of Protoss Shields and different Armors.
Marines take 26 Hits to kill a Zealot in general, 22 if he has Damage Upgrade advantage. It takes 34
hits to kill a Stalker before upgraded, 25 after. This general theme carries on for the Marine. For
Marauders, 16 for a Zealot, 9 for a Stalker and 19 hits for a colossus change to 15, 8 and 17.
So the Attack Upgrades turns out quite crucial.
Last but not least, a forecast on Mech Play:
Attack Upgrade on Tanks changes the amount of hits on Stalkers from 4 to 3, on Colossi from 8 to 7,
and the shots on Zealots from 5 to 4.
On the Protoss side, let’s first take a view on damage upgrades.
Zealots take 1 less shot on Marauders, their hits on Marines remain. For Stalkers, the Marine hits stay
same, while they need one less hit on Marauders, and as well on tanks.
For Immortals, the Upgrades don't change anything, Colossi take down Marauders in one less hit.
So bottom line, when facing massive Marauders, upgrades can make a difference.
On a glimpse to Air, we can see how Void Rays perform against Marines and Phoenixes against Tanks:
8 Shots for a Void on a Marine before Upgrades, 7 afterwards, so a +1 might be helpful. Phoenix
Shots on Tanks drop from 20 to 16.
To remain is how armor research changes the game. Marauder Damage does get affected only
slightly, Stalker endurance does not change, while Zealots die in 1 less shot, Colossi don’t take more
Against Marines, Zealots hold of 5 more shots, Stalkers 4, Colossi 10.
Ship plating shall be viewed on as well, 5 shots more can be taken from a Marine.
The typical matchups in this matchup that might occur from the Zerg point of view are Zerglings,
Banelings, Roaches or Mutalisks against Marines, Marauders, Hellions, or Thors.
If Zerg is facing a Bio heavy play with Ling+Bling, the +1 Armor increase the amount of hits Zerglings
and Banelings take to kill by a Marine by 1, so we here found our first critical upgrade. This also holds
for Roaches, as the Marauder hits increase from 8 to 9, and Marine hits raise drastically from 29 to
The damage upgrade depends, as Melee changes Zerglings against Marines, though banelings don't
get affected. Roach hits don't change on Marines and Marauders at all.
Mutalisk hits on Marines don't change, but the Marines need 4 more hits on Mutas in case carapace
For the Terran, the Damage upgrades lets Marines take less hits on Zerglings and Roaches, hits on
Banelings don’t change. Marauders hits don't change on Zerglings and Banelings, but the Roaches fall
On Mutalisks, you need 18 compared to 21 shots, quite a drastic difference.
Armor also changes much if you encounter Zerglings, as marines remain unaffected when they
counter banelings or roaches, though Zerglings take slightly more hits (9 to 11) to kill them.
Marauder math doesn’t change against Roaches or Banelings, Zerglings need 42 instead of 32 hits.
The whole math of course changes, if the Terran goes Mech.
For Zerg, this means Armor Upgrade is crucial if you go Zerglings, as then the Zerglins survive a
(sieged) Tank shot. Banelings though die anyways, but Roaches survive one (sieged) Tank shot more
as well. As well to note, against hellions, the upgrade doesn't change anything, regardless of blue
Zerglings of course profit from damage upgrades because of their attack speed as the Hellion hits
decrease, and tanks take less hits, but even more Roaches as hits decrease from 11 to 10 on tanks.
The Mutalisk damage might be the most important, as Zerg typically ends up high on Mutalisks, and
the upgrade changes hits on tanks, and, more important, on Thors from 50 to 45. On as side note, as
common sense might suggest, rushing for Flyer Armor doesn’t make sense as it does not even
change the hits on the Mutas for Thors, but very well does +2 carapace lower the hits taken if Terran
has no additional Upgrades.
For a meching Terran, upgrades always make sense because of the superlinear damage increase
compared to armor upgrades.
On 'critical' side, a damage upgrade doesn’t have critical effects on ground or air.
But the Armor upgrade changes things quite a lot. Thors take 5 more hits from Mutalisks, 2 more hits
from roaches, stunning 34 more from Zerglings.
Tanks sustain one more shot from roaches, 13 more against Zerglings, 3 more against Mutalisks. Even
Hellions take longer to kill Zerglings.
A deep Analysis on Upgrades in PvP at the current state of the game doesn't seem to make much of a
sense, as PvP is the shortest matchup in average game time and most of the time ends on 1 base.
Warpgate builds at the moment are designed to kill the opponent before the game gets deep, and
early Forges are built for cannon rushes.
So the only cases currently that might end up in the opportunity to get upgrades seem to be Robo vs.
Robo builds and getting air, so I will investigate those two cases.
The first case is most likely Zealot Stalker Immortal Colossi vice versa, so we will look into that, but
not looking to every matching specifically. The most interesting part might be, if one player can let
his Zealots live longer, Stalkers kill faster, and both for Immortals and Colossi.
So let’s look into these issues: Zealots take 12 hits from Zealots, 17 hits from Stalkers, 8 from
Immortals and 6 hits from colossi. Once Armor upgrades are out, it takes 12 from Zealots, 18 from
Stalkers, 8 from Immortals and 6 from Colossi, so no effect at all.
Stalkers on Upgrades kill Zealots now in 15 hits instead of 17, Immortals need 1 less shot, Colossi
need 27 shots before upgrade and 25 afterwards.
'Naked' Immortal and Colossi analysis against Zealot, Stalker, Immortal and Colossi provides 8, 4, 15
and 8 respectively 6, 6, 13 and 13 shots to kill and 21, 25, 15 and 13 respectively 24, 27, 8, 13 to get
With upgrades, to kill the amount of shots they need are 8, 3, 14 and 7 respectively 5, 5, 12 and 11,
to get killed, the numbers change to 23, 27, 15 and 13 respectively 27, 28, 8 and 13.
So we see the Stalkers, but even more the Robo Units profit from an Attack Upgrade. On Armor Side,
it slightly benefits the durability of Robo units against Gateway Units.
The second notable duel were upgrades are possible (at least for the air unit) might be VoidRay
versus Stalker, so let’s at last take a look at that.
Voids need 17 shots before and 16 after a +1 upgrade, which means 4 Voids can take down a stalker
in 4 volleys. It takes 25 shots from a Stalker to kill the Void Ray, after Armor Upgrade this gets 27.
So after all, Air Weapons might change things in this engagement.
The three scenarios I will address are Bio vs. Bio, Bio vs. Mech, and Mech vs. Mech.
So… let's see what a Damage Upgrade in Bio battles can change: unupgraded Marines need 8 hits for
another Marine and 25 hits for a Marauder, with upgrade the hits per Marine drop to 7, and the hits
per Marauder drop to 21. For Marauders, 5 hits per Marine remain untouched, and Marauder 7 hits
drops to 6.
If you research armor, the hits Marines need for other Marines increase by 1, the shots for
Marauders on Marine remain untouched. For Marauders, it means Marines take 32 hits to take them
down; other Marauders will not be influenced.
If it happens that a Mech army battles a Bio army, things start to differ.
Siege Tanks take down Marines and Marauders with huge overkill, same goes for Hellions, so Armor
Upgrades don’t change much here. But to thin out the lines, Attack Upgrades are crucial for the Bio
player. Marauders take 1 less hit to kill Tanks, Marine shots drop from 32 to 24. So, contrary to visual
impression, the Bio army should prefer attack upgrades.
For the Mech army, the following occurs: Tanks and Hellions remain untouched by damage upgrades
when it comes to critical upgrades, but Thors get to kill Marauders in 2 hits instead of 3 when having
a damage upgrade.
The Armor Upgrade on Mech changes mainly Marine hits. Marauders still take 9 Hits to take out a
tank, Thors die in 23 instead of 22 shots, the Marines hits obviously get drastically affected as 8 more
hits for Tanks, 20 more hits for Thors and 3 more hits for Hellions are required.
In Mech Battles, the most interesting Parts are Tanks vs. Tanks and Thors, and Viking Battles for
As Tanks kill other tanks on Siege with huge overkill (4x (50-1) - 160 = 36), Armor upgrades do not
affect this setup at all. Same math applies on Thors.
But when damage upgrade is conceded, things get interested. Due to huge scaling of Siege Tank
Damage, we will dig deeper into this. After one attack upgrade, Tanks kill Tanks in 3 shots instead of
4. And, as a matter of fact, once your Tanks have +2, Tanks kill Tanks in 3 shots regardless of the
opponent’s upgrades. On a side note, the Thor overkill is too huge to make any reasonable
The Viking against Vikings math presents the following:
Vikings kill Vikings on 5 Shots, regardless of upgrade advantage or disadvantage.
And, as a bonus lolly, Cattlebruiser against Viking math as upcoming Late-game opportunity: It takes
a Viking 25 shots to take down an unplated Battlecruiser, 28 shots on Level 1 plating. So it highly
depends on the situation if the +1 is worth is, the effect of course raises drastically and if you can
afford massive upgrades on Battlecruisers, Marines and Thors do 4x2 respectively 2 damage per shot,
so Vikings are the only opportunity at all left.
The last matchup to be reviewed is Zerg Mirror. In this matchup, the common confrontations are
Zerglings, Banelings and Roaches against each other, and Muta Battles. I won't investigate on Hydra
against Muta unless popular demand, as mostly there is Fungal around once this happens and the
critical upgrades get pointless.
First, analysis on Zerglings. Against Zerglings and Roaches they need 7 and 37 hits before upgrades,
and die to 7 and 3 shots, and one Baneling burst.
On superior upgrades, you need 6 hits to kill Zerglings and 29 to kill Roaches, and need 9 and 3 shots
to die, but survive one Baneling burst.
If Roaches have armor, you need 50 (read: forever) hits.
As you shouldn’t run banelings into Roaches, I won't touch this, so let’s see how Roaches perform:
You need 3 shots to kill a Zergling and 10 to kill a Roach before upgrades, with upgrade its 2 shots for
a Zergling and 9 for a Roach. Once armor is out, Roaches need 11 shots on Roaches.
So upgrades seem viable in every circumstance so far.
Muta against Muta raises the following:
14 shots non-upgraded, 13 when upgraded on damage and 16 when upgraded on carapace show
how fragile this can turn out, but of course corrupters mess with this a bit.
+1 Melee Upgrade: 15% less hits for Zerglings in every setup.
+1 Range Upgrade: Hydras kill Zealots in 2 and Colossi in 1 less hit. Roaches need fewer hits
for every unit.
+1 Carapace Upgrade: Roaches and Hydras take more hits to kill, especially Roaches surviving
another immortal shot (4 instead of 3).
+1 Flyer Damage: Mutalisks need 2 less shots on Stalkers, 1 less on Sentries, and Corrupters 2
less shots on Colossi.
+1 Flyer Carapace: Mutalisks sustain 2 more shots from Stalkers and 4 from Sentries,
Corrupters 2 more shots from Stalkers
+1 Ground Attack Upgrade:
o Vs. Zerglings: Hits for Zealots against Zerglings drop from 3 to 2 (side note +2 vs. +1
and +3 on Colossi make Zerglings one-shot)
o Vs. Roaches: 1 less hit for Zealots, 4 less for Sentries, 1 less for Stalkers.
o Vs. Hydras: Hydras die in 1 less hit against Gateway units.
o Vs. Mutas: 1 less hit for Stalkers, 2 for Sentries.
+1 Ground Armor Upgrade:
o Vs. Zerglings: Zealots take 9 more hits, Stalkers 7, Immortals even 17.
o Vs. Roaches: Zealots take one more hit.
o Vs. Hydra: Zealots take one more hit.
o Vs. Mutas: 2 more shots for Stalkers, 1 more for Sentries.
+1 Shields Armor Upgrade:
o Vs. Zerglings: Stalkers take 4 more hits on their Shields.
o Vs. Roaches: Roaches need 6 instead of 5 hits to clear Shields from Stalkers.
o Vs. Mutalisks: Stalkers take 1 more hit from Mutalisks on their Shields.
+1 Bio Armor: Marines and Marauders take more hits from Gateway Units.
+1 Bio Attack: Marines kill Zealots in 4 and Stalkers in 9 less shots, Marauders kill Zealots in 1,
Stalker in 1 and Colossi in 2 less shots.
+1 Mech Attack: Tanks take 1 less shot on Zealots, Stalkers and Colossi, Hellions kill Zealots in
6 shots instead of 7, and Stalkers in 20 instead of 22 Shots. Thors kill VoidRays in 9 instead of
11 Shots (Side note: +3 Hellions makes kill Zealots in 6 shots, +3 Thors always kill Phoenixes
in 3 Shots instead of 4, +3 Thors kill Colossi in 5 shots instead of 6, all regardless of upgrades.
+1 Mech Armor: Thors take more shots from every unit then Immortals. Hellions take 1 more
hit from Zealots.
+1 Air Weapons: Vikings kill Colossi in 13 instead of 14 shots.