Observation
AoE units in SC2 are generally terrible in low numbers but grow exponentially more powerful in large numbers as opposed to their BW counterparts.
The Why
This is pretty clear to everybody that has followed both BW and SC2, AoE units in general have traded individual force for strength in number.
The question is obviously why? The answer is obvious, the simplification of unit controls from the refined AI and UI of SC2: no more 12 unit selection limit, smart fire added to most units, better pathfinding, smart cast etc.
Modernization, at a price
While many of these changes have rafined Sc2 and brought it into the 21st century, it also came with some unforeseen consequences. The first consequence was that macro became easier for all races, the second was that unit control became easier as units became smarter and more efficient.
Blizzard however did realize that macro would become easier due to the game changes and thus they refined and advanced RTS design by introducing the macro mechanics to add back skill to macro and differentiate between good players and awesome players. The macro mechanics themselves had their own unforeseen consequences upon the game, but in principle the idea was solid, since the idea had UI had been simplified then add back some mechanics to increase the skill of macroing and add ways for the better players to differentiate themselves.
However what Blizzard did properly anticipate was how the intelligence of the new units would create a divide between how AoE units scale and how non-AoE units scale.
How AoE units scale
AoE units benefit a lot more from these UI improvements, they become easier to control and they become much more efficient at killing units, up to the point where in clumps their firepower grows exponentially. Thus we can conclude that AoE units efficiency scales on numbers.
Non AoE units firepower scales linearly not exponentially with numbers, however their resilience does not scale in numbers, but rather with micro, since you need to spread them out to counter the effects of AoE, but also to take advantage of terrain.
This leads to a discrepancy in skill between AoE units and non AoE units. AoE units now require hardly any maintenance to be efficient at killing, especially once critical mass is reached, however non AoE units require constant micro and control, from splitting and stutter stepping to focus fire and focus kiting just to squeeze them maximum efficiency out of them. This difference in scaling, AoE units with numbers and non AoE with micro, makes AoE units feel obnoxious, punishing and at times downright unfair to play against.
The Implications
This extreme power growth of AoE units lead to several nerfs on all of them, from siege tanks and storms to colossus and ultralisk. However this had another and more tragic consequence, it made units much worst individually, meaning that units that were originally intended for zone control and to function in slow unit counts, became far worst at their job of controlling space, the biggest victim here being the siege tank.
This has major implications for overall strategy and map making.
Firstly, it generally favors strong and mobile unit compositions in the early game. The strong army can be used to both secure one's own bases as well as deny and pressure the bases of the other player.
On Strategy
If a player decides to tech and get his strong AoE units, then he is forced to turtle and expand slowly, thus giving up map control. In general loss of map control results in the loss of a game, making the game unfair for the teching player.
However depending on the architecture of the map, if the turtling player is allowed to get a easy to moderately hard to defend 3rd, then he can possibly reach his critical mass of AoE units. At the point his army reaches critical mass, which for mech is around 180 supply to maxed, the army basically becomes an unstoppable deathball. The response to a deathball is another deathball, and if one race is incapable of reaching a appropriate deathball to counter the other race's deathball then that other race will generally die. Thus AoE units become unfair and even punishing in the late game.
This in turn restricts map making and leads to some uninteresting dynamics. Maps always need to strike a certain balance between difficulty to hold and attack a 3rd base. Too hard and slower strategic styles are eliminated completely, too easy to hold and turtle deathball styles cannot be slowed down and then stopped later game. And to a certain extent, maps always need to be unfairly imbalanced in favor of the mobile style. From a viewer point of view its more exciting to watch mobile styles and also to see them clash and chip away at a building deathball, but also because the economy is such that past 3 bases the mobile style doesn't get any benefit from his map control and potential extra economy afforded by it.
AoE units and their counters
Also, because AoE units are so strong in large numbers, they need very strong counters, as in hard counters, just too keep them in check. The problem is, unless the hard counter to AoE units is another AoE unit they will general scale quite differently depending on the stage of the game.
If you design hard counters to AoE units to be able to fight AoE units in the late game at their peak power point, then these hard counters become disproportionately strong early game to the units they are supposed to counter.
This dynamic is again perfectly exemplified in the WoL and HotS by the dynamic of siege tanks in TvP. Lets be frank, siege tanks in TvP flat out suck, due to how strong they can be late game, their counters in Immortals, Zealots and Archons beat them late game, but they also murder them early game, making any sort of mech opening a joke on most maps.
The Legacy factor
In Legacy however, this problem will only grow bigger as the proposed resource model puts a clock on how long you can stay on a small number of bases before you can expand, and it opens the door for a whole slew of expansion denial related timings to emerge that are meant to kill these kinds of styles just as they begin.
Even if we were to adopt the alternate resource model proposed by Team Liquid, it is still abundantly clear that certain units will require a rework of sorts because the dynamics and the balance of the matchups will be different.
Deathballs were never really killed
Nope, the problem was mostly swept under the rug instead of being addressed directly. Instead of touching how AoE units work and changing the way they scale, we instead got units like Swarm Host, designed to fight the ultra efficiency of mass AoE units via the ultra efficiency of free units, which ultimately resulted in a very boring and stale game type.
It has also resulted in big restriction on map making now and until the forseeable future. Because of how strong mech and late game protoss is. Map making from the SH patch till either Legacy release or the next major redesign of AoE units, will be forced into the following design.
Third and 4th bases will have to purposefully be made hard to hold by slow styles like mech because once they get going they become unstoppable by zergs. At the same time maps still need to be balanced in TvP and in Bio vs Zerg.
Its the same dynamic as back in WoL, where toss and terran were on a clock to do game ending damage to a zerg until BL/Infestor came online, and we all know how much we loved that.
The Potential Fixes
Now that I've fully explained the problem of AoE unit design in SC2 and their implication upon strategy and map making I shall go to the heart of the issues.
AoE units, every single one of them, needs to be redesigned so that they are better individually, but worst in medium to large clumps.
I propose the following changes.
1st AoE units, no longer have smart fire.
Example, if one zergling is in range of 20 siege tanks, or 20 colossus, etc, then all of them will fire and waste shots on it. This adds back the critical dynamic that is missing from AoE units. They start scaling with micro again and their positioning becomes more important.
Take BW tanks for example, how to properly place them was an intricate art. If you clumped them too much they lost both firepower and survivability. Firepower from the fact that you could bait them all to fire on just one or two targets before rushing them. And survivability, because you could use their AI against them to drop individual units on top of them and make the tanks destroy themselves.
However if you split up tanks too much they lost their ability to control space against much larger armies and their ability to protect each other.
If you struck the balance just right your tanks could reach maximum efficiency, but of course there was counter play, it too more time and attention to setup such a tank line meaning there were more windows of opportunity where you could directly assault it and break it. And even if you did get the positioning right you were still expected to focus fire your tanks on certain targets to get the most out of them.
2nd The big AoE spellcasters lose smartcast
AoE spellcasters have lost a lot of their luster. In BW, just a few well placed spells could turn a entire fight, in SC2 their efficiency resulted in a direct nerf which made spell casters feel less impactful, less satisfying and overall less rewarding. But it also had the unintended side effect of making mass spell casters overpowered in certain situations. The worst offenders were early WoL sentries, Khaydarin Amulet high templars and WoL infestors. I concede that certain spell casters, like the sentry, would probably be underpowered and unusable without smart cast. I won't go into the dynamics of forcefield, that merits its own discussion, but I'm just conceding that not all spellcasters need to have smart cast removed. However the casters with the big and impactful aoe spells, the spells that can literally turn entire late game fights on their heads, should have smart cast removed. At the moment that means, Ghosts, High Templar and Infestors and Ravens. I am unsure about Vipers because they don't deal damage, however their spells are still strong enough that they can turn fights so they probably should be lumped in there.
Removing smart cast on these units adds two benefits. Spells can be buffed to become more satisfying and impactful. More importantly though, there will be one more incentive to not mass spell casters. The first incentive to not mass spell casters was that some point their supply count would eat into the supply you had available to build a buffer to keep them safe. However as was the case with certain units like WoL infestors and HotS Ravens, there came a point where the potency of the spell caster far outweighed their need for a buffer.
The removal of smart cast makes it so you have to dedicate more actions to controlling them properly, making them not only more skillful but putting a soft cap on how many you can efficiently control before you start neglecting the rest of your army.
Technically, isn't the removal of smart fire and smart cast a archaic dumbing down of the game?
This is probably the first question that is going through your mid as you read my proposals. The answer isn't a clear yes or no however.
Yes, technically, removing smart fire and smart cast is dumbing down the aoe units, but, is it really archaic? The units are actually still responsive, they still move exactly the way you tell them, they still automatically fire when enemies get too close. However now they require more control to get the most out of them.
Smart fire right now feels like units with bonus damage to armored automatically targeting armored targets first. Now thing how such a proposed change impacts the game. There is now less need for fancy micro and targeting, there are less ways for players to differentiate themselves in skill. Worst still the efficiency of the units now has to be accounted for in balancing which further reduces how impactful micro is allowed to be on them.
Will these changes alone to AoE units be enough?
No, obviously not, this change will lead to the necessity to change the stats on every single aoe unit and spell and also completely change their units. In principle it should hopefully lead to less hard counters and give more skill to the players.
Even after all redesign of the units in the game has taken place it is hard to say for certain if the changes are alone enough. SC2 is a incredibly big and complex game. It might be that further changes would be needed, something along the lines of a aura on certain aoe units or casters that makes the same unit of that kind around it deal less damage, just as an example. I am hoping however that we need not resort to such designs as those actively punish you for massing AoE units, instead of rewarding you for using them properly and discouraging you too make too many.
Conclusion
The moral of the story is. Good unit design doesn't imply that units have to be smart, good unit design is implies that units are responsive and their power level directly correlated to the skill of their user.
Making the AoE units too smart and efficient in SC2 in the first place has actually taken skill and potential out of the hands of the players and has had a ripple effect on the entirety of the game, from the way units and hard counters work to the way maps are designed.
If we want Legacy to be a truly great game to stand the test of time, then not only does the economy need to be changed, but the units themselves.
If you are a fan of strategic choice, if you want both bio and mech to be viable and if you don't want mech, or protoss late game to ever be just a unfair turtle to max deathball style, then I hope you can understand the necessity of this change.
Leave comments and feedback, propose and debate the merit of alternate change, perhaps you can come up with better ideas to re balance AoE units, after all I am just human. However lets keep the discussions civil and focused on the point, which ultimately is to make this game better. SC2 fighting!
SC2 fighting!