An Improved Design? The Disruptor Catapult

Produced from the Robotics Facility:
Build Time: 20s
Minerals/Gas: 175/125
Supply Cost: 4

Ground
Shields/HP: 100/250
Base Armor: 1
Speed: 2.5

Abilities --
Build/Hold Disruptor:
Builds a charged Disruptor. Cannot be Chrono-boosted. Can house a single Disruptor and charge it. The Disruptor is destroyed if it is housed inside a Catapult when the Catapult is destroyed (similar to Interceptors inside a Carrier).

Launch Disruptor:
Launches the Disruptor, automatically causing it to use Discharge if it is charged. An uncharged Disruptor may not be launched (alternative: charging is in time or burst increments, and time in Discharge mode/number of Discharge bursts depend on how long the Disruptor has been charging; alternative 2: an uncharged Disruptor is simply unloaded like a unit in a Bunker).

Load/Recharge Disruptor:
Can load a single Disruptor and recharge it. Recharge time: 10 seconds. Recharge progress is reset if the Disruptor is launched before being fully charged (also, see alternatives for Launch Disruptor).

Built from the Catapult:
Build Time: 20s
Minerals/Gas: 75/75
Supply Cost: 2
Remains in Catapult until launched.

Ground
Shields/HP: 100/50
Base Armor: 1
Speed: 2.8

Ability: Discharge
Duration: 3.5 seconds.
Can only be cast by being launched from Catapult when charged. The Disruptor must be recharged inside a Catapult before it can use Discharge again.
Is invulnerable and can move through units during Discharge.
Deals 5 bursts of 30 damage over .75-second increments, beginning at 0.5 seconds: 0.5 seconds, 1.25 seconds, 2 seconds, 2.75 seconds, 3.5 seconds. Radius: 1.75
(See alternatives on Launch Disruptor from the Catapult)
Speed during Discharge: 3.4
The Disruptor constantly travels at this speed during Discharge. It cannot slow or stop during Discharge, but can be steered by using move and patrol commands.

Many people have been discussing splash from the Robo, often discussing Disruptor changes and the Reaver.

Each has its pros and cons. The Disruptor essentially must separate itself from the rest of the army to be effective. However, this makes a rather inflexible all-or-nothing design, where you usually deal a lot of damage, or lose the Disruptor after the attempt -- a hefty loss of 300 gas. There are some cases where some damage is dealt and the Disruptor escapes, but the whole invulnerability --> defenselessness aspect can be frustrating for both sides when combined with the single burst of damage.

If the gas cost was reduced to, say, 200 or 150, but the Disruptor only *almost* killed a group of units, you would want to bring 2 Disruptors which is a bit counter-intuitive. To avoid needing to commit a large amount of gas to deal some decent damage, you would need to reduce the cost and damage to a point where it was essentially like a big Protoss Baneling, and I don't think an altered version of another race's unique unit is the way to go.

High burst-splash damage is also punishing on casuals (more so with the Disruptor than with Banelings and Widow Mines which can be killed from a range in engagements even when they're being used) while often being inconsistent at the pro level. Consistent damage over the duration of Purification Nova would help, but then you have the issue of the "untouchable" Disruptor that deals *some* damage and then runs out of reach of retaliation.

The Reaver's Scarabs, if they act like units, can force the Protoss to split their army to allow the Scarabs through or risk the Reaver being in the front lines, creating some positional potential. However, the Reaver is slow, fragile, and expensive, meaning you still need to keep it with a large army to protect it (though, losing a Reaver would not be such a hefty loss as losing a Disruptor).

This also makes it harder to cover much in terms of defense without reliance on Warp Prisms, which adds to the cost and creates a weakness of anti-air similar to the Colossus, which contributes to the Colossus being a deathball unit as you need more units to protect it (but not entirely to the same extreme as Reavers can still somewhat function without Warp Prisms).

Scarabs also have the same high burst-splash damage that can greatly punish casuals while not being consistently effective enough at the pro level.

Honestly, I don't believe you can completely solve the deathball problem until the Gateway can produce a solid core composition against many armies (not just Bio). However, that does not mean we have to limit ourselves from having a well-designed damage-dealer from the Robo that does not contribute to the deathball problem.

I believe the idea of taking the best aspects of the Disruptor and Reaver and discarding the worst aspects of them is worth looking into.

The concept of a price for a missile is an interesting limiting factor, but a controllable and reusable missile is also interesting and fun. But an expensive, controllable, reusable missile seems to have unfavorable results.

As mentioned before, though, a Protoss Baneling is not wanted. You can't really reduce both the damage and expense by only a little -- or even half in the case of the Disruptor -- or you will simply have to use two of them to be worth it, countering the whole point of reducing the cost and damage in the first place.

However, if you can somehow split the cost of it into something else -- like a launcher -- you can have a cheaper missile with similar power that has another limiting factor (the launcher). There is still some investment in the missile, but not all of it is risked by getting up into the opponent's face with it. The Disruptor Catapult is based upon this concept. The Catapult can act as a powerful ranged unit by using a powerful melee unit and vice-versa, but the two must go together.

At the same time, you don't need to have all of the investment in the ranged unit, so it's not as imperative to keep a large army with it. The durable and moderately quick Catapult has some flexibility in positioning and doesn't entirely anchor the rest of the army to it, but it can still be caught out of position. As it relies on the Disruptor to deal any damage, there is more room for less reliance on the rest of the army to escape or be involved in skirmishes.

This, however, does not yet address the issues that come with high burst-splash damage combined rigid invulnerability/vulnerability and the fact that, while not necessarily a deathball unit, it can be easily used as one.

This is where Discharge comes into play. The more consistent damage allows the Protoss to choose to escape before all of the damage is dealt, and the reliance on the Catapult means that if the Protoss does escape, there is still a way to essentially nullify the Disruptor as the Catapult is never invulnerable. You could have 10 Disruptors which are useless if there are no Catapults, or if there are only 1 or 2 Catapults, the Disruptors can only be used at a slow rate with the recharge requirement.

The consistent damage combined with the "skillshot" aspect, as the Disruptor constantly moves at a high speed during Discharge, means you are punished (but not super severely) for having a lot of units in front of where the Catapult is aimed, while at the same time you are rewarded for using the Catapult at the front of the army or splitting up your units to allow the Disruptor through.

This has a similar effect that Scarabs from the Reaver would have while retaining the pass-through aspect of the Disruptor (which I believe is an interesting aspect and helps to make the consistent lesser bursts have potential to do damage if used well). In fact, the consistent damage adds more positioning potential than the Reaver as getting the Catapult closer to the opponent allows more opportunity to deal more bursts of damage.