How does the Roach work?

[Nicol Bolas]

Incoming wall of text. Scroll to the bottom to see the tl;dr version.

I've been thinking about this for a while now. And I haven't found an answer to this question yet: what exactly are these things for?

In refuting arguments that the Zerg are broken based on various videos, I find that I'm always citing the lack of use of various facets of Tier 2. They didn't go for Infestors. Or they didn't use their Overseer's abilities. Or no Nydus or Overlord drop play. Or whatever.

At no time have I seen a situation where I thought, "You know what this Zerg player needs right now? Some Roaches."

What would that situation look like? Does that situation even exist? I've been hypothesizing, and I can't come up with a legitimate eventuality where Roaches would actually save someone.

The common thought for Roaches is as tanks for Hydralisks (since Hydras out-range Roaches). However, for the cost of a single Roach, I can get 4 Zerglings (or more Hydralisks, but we'll focus on the Zerglings for now). Together, they can absorb 140 damage, which is almost the Roach's Hp. However, since many units will over-spend to kill Zerglings (hitting a Zergling with a 20-point blast when it is on 5 Hp), this can be raised to ~155-160, depending on what's shooting at them.

Roach regen, at this point (Tier 2: 3 buildings in), is sufficiently slow that you can only expect them to regenerate maybe 10-15 Hp before they die or you are forced to burrow them. That's 185 Hp vs. 140, worst case. A 25% reduction is certainly significant, but far from earth-shaking.

It should be noted that Zerglings do a metric assload more damage than Roaches. The only downside other than the 25% expected health reduction is that Zerglings are melee-only: thus, there's a fairly low limit to the number that can attack something. Even so, substituting one Roach for just 2 Zerglings is still more damage.

So where are Roaches an overall win? AoE. Zerglings die quick, bloody, and en masse to most AoE. Roaches do not. But even here there is a problem. And I think this illuminates the Roach's problem overall.

So your Roaches survive that Psi Storm. But they won't survive it because of their high Hp or regen. They will survive it because no Protoss player will aim at them. The Psi Storms will be aiming at the Hydralisks behind the Roaches. This is similar to how a Protoss will react to Thor+Marines.

However, there is a difference between Thor+Marines and Roach+Hydralisks. And that difference is this: Roaches are not dangerous. At all. Against anything.

Thors, by themselves, cannot be ignored. They do far too much damage far too quickly to ignore them. Oh, you shouldn't fling Psi Storms at them, but they're a perfectly legitimate target for Phase Out. There are entire units specialized for dealing with Thors (Immortals and Void Rays, for example).

Roaches... not so much. And that's the problem.

In an MMO, a tank class can force an enemy to attack them. They do this by using abilities that manipulate Aggro, the AI system that determines who the monster attacks next. In an RTS however, there's nothing to make someone attack a unit. People will naturally attack the unit they find to be the most dangerous.

You can't ignore a Thor. Nor can you ignore an Ultralisk. Or an Immortal. Or an Archon. All of these units will kill people and break things; they will do so quickly and savagely. You have to attack them, sooner or later.

Roaches... not so much. They do pitiful damage, and their rate of fire is maybe as good as a Hydralisk. But Hydralisks get to attack air and ground, as well as have a bonus to the kind of unit that tends to have high Hp (armored). Roaches don't. Hydralisks have range. Roaches don't.

The only threat posed by a Roach currently is that it's semi-hard to kill. This is mostly due to its Hp, not its regen. And there's the problem: Roaches may be the first to the fight, but if it is at all possible to get around them, then the enemy will. They're not damage dealers, so there's no reason to attack them right now. Better to take out what they're protecting now and deal with them a bit later.

In order to do what a Roach is supposed to, it must actually be a threat. A team of 7-10 Roaches had better pose a threat to something. And this gets into a possible Tier 2 weakness: taking out armored units.

Banelings have AoE covered reasonably well. Hydralisks are good at just about everything. Zerglings are, well, Zerglings. In SC2, there are a lot more high-Hp targets at lower Tiers than in SC1. Thors, Marauders, etc.

Hydralisks are generalists: they can handle everything approximately equally well. But because they have no weaknesses, they have no strengths. A unit designed specifically to take out light units will have a field day with them.

Roaches can cover this. Give them an attack of perhaps 10 + 15 vs. Armored. That will make them a certifiable threat against Thors, Siege Tanks, Stalkers, Immortals (once the shields are down), Marauders, and so on.

tl;dr: Roaches aren't good tankers because they aren't dangerous to anything. Give them a large bonus vs. armored units to make them dangerous.

[flabortast]

I'd agree but wouldn't giving a relatively massable unit a strong attack be dangerous?

[PsiWarp]

True, the Roach (as of current) does seem to focus on tier 1 rather than higher tech, so the Hydralisk would remain uncontested in its go-to nature due to Anti-armor + Anti-air capabilities.


-Psi

[Caliban113]

How about giving the Roach an attack similar to the Devourer's acid spore attack in BW? - an attack which is weak on it's own, (like the Roach's current one) but creates a temporary effect (on certain unit types - armored?) that increases the amount of damage made by other units. (or in some way lowers the effectiveness of the target)

[PsiWarp]

I think it'd be cool if the Roach has a passive ability which prevented HP or Energy regeneration of any type, spell (Medivac Heal, SCV Repair) or natural (Zerg Regen, Shield Regen), for perhaps a second or more.


-Psi

[Gifted]

Before I even give an opinion, to help form my own opinion and any other opinions from this point forward I think it's good to bring the current statistics to the table that I have access too. There are also ways to judge the statistical advantages of DPS, range coordination, time charts and whatnot. I'm merely judging by basic elements for this conversation. Information provided may be flexible based on balance and should not be treated as law.

Unit Statitistical Comparisons

Damage

Roach: 11 damage (+3 light)
Hydralisk: 8 damage (+4 armored, same rate as roach)
Zergling: 5 damage (No bonus, faster rate of attack)

Armor

Roach: Armored (Biological)
Hydralisk: Light (Biological)
Zergling: Light (Biological)

Hit Point

Roach: 160 (1 armor)
Hydralisk: 80 (0 armor)
Zergling: 35 (0 armor)

Cost

Roach: 100
Hydralisk: 75 / 25
Zergling: 25 (Per unit as they spawn as 2)

Build Time

Roach: 27
Hydralisk: 27
Zergling: 24

Efficiency Ratios

Roach

Damage Cost: 9.09~ per damage ( 7.1428~ against light)
Hit Point Cost: 0.625 per hit point (Not counting armor and regeneration) *

Hydralisk

Damage Cost: 12.5 / 3.125 per damage ( 8.33~ / 2.083~ against Armored)
Hit Point Cost: 0.9375 / 0.3125 per hit point

Zergling

Damage Cost: 5 per damage (Faster rate of attack not included) **
Hit Point Cost: 0.7142~ per hit point

* This value can be reduced by a fraction of one over the damage value of the attacker.
A unit that does 5 damage reduces cost per hit point of the roach by 1/5th (.625 -> .5) for example. This still does not
include increased regeneration to the equation.

** This value is inaccurate due to the lack of a global equal value to judge by. If we
could determine damage per second then we could change these values to be fully
correct. All we know is that the attack speed for the Zergling is faster than the Hydralisk
and Roach. The Hydralisk and Roach have the same attack speed.

Basic jist of opinion:

I can see too narrow of a niche for this unit and agree with your point slightly. Another unit that could stand to be in the same boat is the Immortal as it's most efficient niche is also a likewise narrow situation.

I suspect that our conversation will lead more so into the angle of how to balance it further on paper which won't lead well into real scenarios. That's fine and dandy though as we're examining the unit in terms of counter analysis and not in terms of actual performance.

There are some parts of your information which I disagree with but I think with proper statistics we can reach a same page.

Regarding the roaches' damage output:

I find that statistically the roach has a similar damage output to the hydralisk. When you place it against light units, however, it's efficiency shows to be about par as well in it's current form.

• In ZvZ the roach becomes a sufficiently more efficient unit in terms of damage compared to hydralisks and could replace them in certain counter compositions leading up to mid-game.
• In ZvT, I feel they'll be more efficient against a Terran infantry army that has a low maurader count... the issue is that terrans can swiftly fix that unless there is a focus on the maurader killing. They could also work as planned base defenders against raider guerilla attacks in a pinch with proper scouting.
• In ZvT and ZvZ, 3 Roaches can one shot a worker, allowing them to be the most efficient harrassment drop to an enemy base, especially with burrow being natural to them.

If you still feel the damage of Roaches being light.. feel free to state so. But in light of the statistics I am looking at right now I believe it to be adequate.

To all reading my post:

I hope these statistics help the discussion out to alleviate questions/concerns/misconceptions about what's more powerful or not. These statistics can help you bring your own conclusion to light

[flabortast]

Those stats are wrong. Are you using SC2armory? SC wikia has more up to date stats.

[MattII]

I don't know how true it is, but the wikia states that the Roach's attack is 11 +3 vs. light (everything else is the same though), which, if true, would make it slightly worse vs. bio units, but better vs. everything else, and still more than a match for the Hydralisk vs. light units (and almost a match vs. armoured, less the range).

[RamiZ]

Yup Gifted, as already mentioned those stats are wrong, SC wiki got stats from November 2009.

Roach does now 11+3 vs light -.- Which sucks in my opinion.

I don't know how true it is, but the wikia states that the Roach's attack is 11 +3 vs. light (everything else is the same though), which, if true, would make it slightly worse vs. bio units, but better vs. everything else, and still more than a match for the Hydralisk vs. light units (and almost a match vs. armoured, less the range).

True, but we already have Hydras that are doing bonus to armored, why don't we get Roach bonus to biological or Light? And I pretty much agree on anything Nicol said, except 10+15 would be too powerful, and Hydras already do 8+4 vs Armored. So I would say, give them something like 10+10 vs Bio units, or light units. But I think they will buffed it, or do something about them.

[Gifted]

Thanks for the clarity, updating it.