I'll be honest here: While I did enjoy GalCiv II and its expansions immensely, not being able to influence a battle at all would be a pretty big no-go for me. On the other hand, real-time combat, like in SotS, would IMHO bog the game down far too much and take the focus away from the strategic parts. Turn-based combat, i.e. somewhat similar to Elemental, would also have to be done extremely well and entertaining to fit in.
So I've been thinking about a possible solution and simple system that would give both sides participating in a battle various options; some general in nature, some more geared towards specific ship types or weapons. And not just a straight rock-paper-scissors system either, because those are boring and too simplified (Endless Space, I'm looking at YOU!). In the end, something like found in Birth of the Federation would seem to fit, that is, giving orders at the beginning of the battle and watching things play out afterwards (with a twist, though - in BotF you could give multiple orders of the course of a battle). This is what I wrote down yesterday, I just didn't bother posting it anymore because the forums were extremely slow for me (and I was starting to fall asleep):
Tactical Combat proposal for Galactic Civilizations III
Orders can only be issued once per each battle round. One round takes one turn on the strategic map. Should the combat not be resolved within one turn/round because both sides still have combat ready units remaining, combat may take more than one turn to end. In that case, new orders can be ordered at the beginning of each turn.
Orders are comprised of 3 components:
1. Engagement Range (i.e. long, medium, short range)
2. Stance / Formation (i.e. offensive, defensive, neutral)
3. Targeting Rules (i.e. focus fire, spread fire, target strongest, target weakest)
I. Engagement Range
This setting can grant bonuses or penalties to different weapon classes. For the sake of simplicity, let's split weapons into categories of energy, ballistic and self-propelled weapons that each have an optimum weapon range where they cause maximum damage. It could look like this (going from short to medium to long range):
### Weapon: Damage at [Short] - [Medium] - [Long] Range ###
Energy Weapons (i.e. Laser): [+20] - [+0] - [-20]
Ballistic Weapons: (i.e. Railgun): [-10] - [+10] - [-10]
Self-propelled Weapons (i.e. Missiles): [-20] - [+0] - [-20]
However, here's the twist: To determine the damage output of your AND your enemies' weapons, both sides' engagement ranges are taken into consideration. The above numbers are just the basic numbers you get from your own engagement range; after both commanders have issued their range orders, the results are like this (and it goes both ways, of course):
Short - Short [+50] / Short - Medium [+20] / Short - Long [+0]
Medium - Short [+20] / Medium - Medium [+0] / Medium - Long [-20]
Long - Short [+0] / Long - Medium [-20] / Long - Long [-50]
Short - Short [-25] / Short - Medium [+0] / Short - Long [+0]
Medium - Short [+0] / Medium - Medium [+25] / Medium - Long [+0]
Long - Short [+0] / Long - Medium [+0] / Long - Long [-25]
Short - Short [-50] / Short - Medium [-20] / Short - Long [+0]
Medium - Short [-20] / Medium - Medium [+0] / Medium - Long [+20]
Long - Short [+0] / Long - Medium [+20] / Long - Long [+50]
As you can see, some numbers deviate from the original values (+/-25 and 50). This is to reflect a perfect match - or the opposite - between the weapon's optimum and the actual combat range. Ballistic weapons in this example also offer less risk, but less potential rewards as well; they perform reasonably well at most ranges.
Keep in mind that the three weapon classes do not have to be limited to a specific ideal range; this was just to simplify this example. It could be possible to add long-ranged energy weapons, short-ranged rockets and other weapons straying from this pattern.
II. Stance / Formation
The stance or formation of a fleet can grant modifiers to offensive or defensive values. Different stances may be better for some situations than others. For example if you are fielding a large fleet against a slightly less powerful foe and plan on running an extended campaign behind enemy lines, cutting down on the damages your ships receive may prove to be more beneficial in the long run than trying to get just that last bit of firepower out of your guns.
Stances and formations can include, but should not be limited to:
Offensive: Grants a +15% bonus to firepower, but reduces defensive values by the same value.
Defensive: Grants a +15% bonus to defenses, but reduces firepower by the same value.
Neutral: Does not grant any bonuses or penalties.
Reckless Abandon: Grants a 30% bonus to firepower, but cuts defense efficiency in half.
All-round Defense: Grants a 30% bonus to defenses, but reduces damage output by half.
Broadside: Grants small offensive and defensive bonuses to larger ships while smaller ships suffer penalties to these values.
Flanking Maneuvers: Grants small offensive and defensive bonuses to medium-sized ships while larger and smaller ships suffer penalties.
Swarm Attack: Grants offensive and defensive bonuses to smaller craft while larger ships suffer penalties.
III. Targetting Rules
These rules are used to tell your ships on what to fire. Different settings can have various effects, with possible sub-settings for each one:
All ships focus on one target. This obviously makes it possible to kill single targets quickly, but also potentially leads to a lot of overkill, that is wasted shots on an already dead target.
Sub-settings: Random, Target Weakest, Target Strongest
Each ship opens fire on an enemy ship of its own size, if possible. If more enemies are present, the ships will try to destroy their targets before acquiring a new one.
Ships that are much larger or have much more firepower in relation to their target's hitpoints may fire on multiple targets simultanously.
Sub-settings: Overkill percentage, number of maximum targets per ship, number of minimum ships firing on the same target
This is pretty much an idea of how tactical space combat in GalCiv III *could* play out. The aim here is to give some ideas how some meaningful interaction could be implemented without bogging the game down with too much time spent in said combat; after issuing orders, it would all just play out similarly to GalCiv II.
Additionally, this would somewhat limit the amount of complexity SD would have to deal with in terms of combat AI. Sure, there is still a lot to consider, but still a good deal less than a hex or grid based turn-based combat system would involve. Some decisions for AI and auto-resolve (IF auto-resolve uses this underlying mechanic to simulat combat) can be calculated by fleet composition and equipment (defenses and weapons) in comparison to your enemy, etc.
And last, but not least, it wouldn't take too much out of the game or change too much of the overall game if a player chooses to disable this (optional!) setting altogether.
Disclaimer: The values are just a placeholder, they could easily be completely different (i.e. smaller).