EPTThe advantage of spell-based macro is in the following:
1. The time intensity of macro (much player need to pay attention to base) can be tweaked by the amount of max energy/cooldown of the castors. To more max energy, the less the player need to pay attention to the castors before they overfill.
2. The level of influence of macro can be controlled by the power of the spells themselves.
3. The effect of macro is far more interesting if the spell casters have a wide pool of spells.
4. Spell effects can be made easily visible to an observer, more so than gateway utilization percentage.
5. The mechanism already exists in the game and does not require completely new concepts and engine changes.
6. Macro requirement can be made into a choice so players can use strategy that avoid using non-combat castors if they dislike macro.
7. As far as I know, there is no widespread call to remove spell casting and proposals from all levels of gamers ask for more abilities.
Now, Concrete examples
I. Zerg
The Zerg Queen unit, being the manager of the hive clustor, is the unit that has non-combat spells. However, currently the spells don't really scale much and need to be modified a bit.
1. Give Hatchery Energy which acts like "shield battery for Queens" where it recharges Queen energy. Give the hatch a low max energy of something like 50 max energy.
2. Queen will have abilities like morphalisk, swarm clutch, creep tumor, Transfusion, swarm infestation, deep tunnel. All will cost more energy (even if it didn't), adjusted for the now greater mana pool.
3. Allow extra Queens to be build upon hive tech, one queen per lair/hive building.
What this means is that Queens will have to constantly travel between hatchery to hatchery (tending the cluster) to get the most out of the energy from the hatchery. Since the spells varies in use, the use of the hatchery/queen energy will differentiate different strategy. This fits both the lore of the queen and gives adds strategy in both energy management, base layout and queen movement routes.
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II. Terran
Terran have highly independent buildings so the Zerg model does not work. However, the Terran already have the Nomad, which is a non-combat caster and one simply need to make it accessible and vital to make macro an important part of the game.
1. Nomad no long require tech lab. However, detection is an upgrade at tech lab and will take energy. (like wraith cloak)
2. Auto-Turret will now take energy. Auto-Turret resource cost dropped.
3. Spider mine expire after 120 seconds. Spider mine activation range 6, hp 30 light.
4. Nomad max energy is 50. Gets upgraded to 150 after a long upgrade. (~210 seconds)
What this means is that nomad will have to be constantly casting new defenses (every 50 seconds or less) to be fully efficient, as it can no longer accmulate a ton of energy. Now by making the nomad defenses strong, it would make the nomad an vital part of the slow push and base defense which fits the terran style while giving it an unique niche. The limitation on detection makes energy management more important and prevents swarms of Nomad nullifying cloaking.
Of course, Nomad is just one unit and within the terran arsonal there are other units that'd fit the role. In this case we call for the reaper which was considered lackluster previously.
1. Upgrade at armory of command detonated charges for the reaper. It will have linked cooldown with existing D-8 charges. It is cloaked and burrowed, has 10hp, does 20+20 damage upon command to detonate. It will take 15 seconds to arm. It does not track and will only hit units directly above it in a medium splash radius, and it has 1 sight range.
This means the reaper will have the additional role of maintaining map control and setting traps left and right like the old vulture. This is a spell that would likely be constantly used (it is free after all) and act as an aggressive APM sink. Bad players that lacks the APM will waste some mines while the cooldown finish.
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III.Protoss
Protoss lacks non-combat casters as it stands how, and its focused and well defined army means there is no obvious use to put the abilities onto. However the protoss psi matrix does offer lore justification for all sorts of abilities within a protoss base. Here is my tentative suggestion:
1. Nexus gains energy, capped at 40.
It gains the following spells:
"WarpTime": Accelerate the time of the single target, which includes everything from movement, attack, energy regen rates or build times (for buildings) by 30% by 60 seconds for 40 energy
"Channel": Can be used to transfer energy to other Nexus or mothership. Unlimited range.
"Cloaking field": Target a pylon within range. The pylon will than project a cloaking field for 1 energy per second after a initial cost of 20 energy.
2. Pylon gains ability "Drain" which converts its own shield to the energy of the Nexus (closest Nexus while under pylon field range) at the rate of 50 shield to 1 energy. It drains at the rate of 25 shield per second.
The abilities are researched at Templar Archives (WarpTime), Dark Obliesk (Cloaking Field).
Since warptime is so powerful, managing the energy is critical and good usage allows the protoss player to "hurry" buildings and bluff "hero units" and will constantly force the protoss player to get back to base to use this spell on whatever the strategic gap of the time.
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All those ideas are just illustrations of how non-combat spells can be made into the game and generate different, interesting dynamics that requires real need to shift focus and control the units directly as opposed to something that is limited due to only hotkey count.
