I generally agree with both the OP and Gauntlet's post above.

Especially this.

And especially this. One nuance to consider: Perhaps in order to retreat, the defending fleet would need to have moves left... in such a case, the attacker could attack again, provided they have sufficient moves to do so, and the defending fleet could again retreat, assuming they had remaining moves. Apart from some mechanism like this, the other option I see is that attacking must use up all remaining moves--which I'm not sure I like... or something far more clever or simpler than I can come up with at the moment.

I guess what I'm trying to say is, while I like the idea of retreat, it does potentially require other changes to the mechanics that I'm not sure about (or that I'd like).

How do other similar games handle this? Or do they not?

The above ideas are fantastic. I am however ignorant to how difficult these would be to implement. I would like to add two things. 

First I would hope if Stardock does enhance the combat they leave an auto resolve option for when you know you’ve won you just have to play the remaining 150 turns to “win”.

Second the prospect of carriers scares the living daylights out of me. They are so damning I don’t use them unless the AI rushes me 2 turns after meeting me at turn 50. I just find them completely overpowered. Put a carrier in a fleet and the only thing that can challenge it is another carrier. I think adding carrier supplies such as a carrier modular that allows you to store 10 fighters that you have to build and deploy three of them per modular in battle. So a huge haul could store 30 fighters and deploy 9 of them in a single battle. If fighters are destroyed they do not regenerate automatically but can be refilled by new fighters. The free generation of the most update fighters is what makes them OP if you increase the logistical support needed for these monstrosities it would improve their fairness. Again I am ignorant to have difficult this would be to code or if the AI could pull this off  successfully. 

Thank you for reading this looking forward to buying the expansion once it drops. Even though you guys removed the tech specializations.

Can't flee combat in civ series. Still great games despite that. I think your complaints are a bit on the petty side. But everyone is entitled to their own opinions.

Getting back on topic... and thinking of do-able and easier to implement changes to the combat system (not thinking a big complete redux with tons of features here)...

Bear in mind my goals: diversity of ship design and the potential for multiple valid design choices:

1) Scanners should impact tactical battles, I would have them impact the accuracy and the RANGE of a ship's weapons. Note, this is a per-ship result... a big sensor boat in the back will not help the fleet in tactical combat.

In-game justification? Jamming and false communications are too likely. Ship's rely on their own sensors when engaging... (sure why not?)

Out-game justification? Opens new combos of possibilities and creates more complication for optimizing ships and their payloads. You could be well behind in weaponry compared to your enemy, but far ahead in scanners giving you a distinct advantage in range.

2) Unused hull capacity/space = either additional ship HP or a slight increase in tactical speed, IE evasion. Lighter ships = easier to move. Not really a big deal, but I just like the idea that the 2-7 slots i couldn't fill helped somehow lol.

3) Carrier fighters that die, regenerate after three turns. Create a new hull category for Fighters that has less space and less health than tiny. Not by much mind you, but a bit. This should nerf carriers in any sort of protracted war of attrition.

4) Reduce roles to three "stances". Aggressive (moves at full speed towards the enemy), Neutral (Moves at 2/3rd's speed towards the enemy) and Defensive (Remains stationary). All targeting is simply on a "whose closest" basis... 

So essentially all ships are "Capital" or "Support" with an additional "Fast" option.

5) Nerf Commanders/Admirals. They are kinda broken. In particular their speed bonuses (which with Hypergates we should need less anyhow).

6) Remove Leaders option to increase fleet HP. This is insanely broken. I can put 10 leaders on HP for an important battle, than instantly shift them back to other priorities. If there must be a fleet Leader use, have it affect strategic repair rates and reduce upgrade costs. Which you know... makes SOME SENSE.

7) Drastically reduce the size of Thrusters and make them one-per-ship.

8) Consider adding a penalty to evasion for each main drive engine you add to a ship. 

That is a pretty good list, and for the most part, could be implemented via modding, so it shouldn't be drastically consuming for the developers. If I thought this was going to be a major focus for an expansion, I'd definitely come up with something more creative regarding the roles, and ideally I'd also radically change the engines into "strategic" "tactical" and "thrusters", and have various advantages and disadvantages to hull sizes in combat both in and out of orbits... so huge hulls SUCK at attacking a nest of 20 tiny hulls in orbit... but can annihilate them in open space.

Etc. etc. Lots could be done... but even a modicum of attention would make the current system more enjoyable.

That's a good point. I'm kind of surprised the default designs are kinda poor, and updating those would help a little. Though the designs are mostly poor because of their engine choices. 

In a perfect world id give the AI a "fleet" blueprint for assembling fleets. If it had that and could somehow flexibly choose to launch ad hoc fleets when desperate and assemble larger thought out fleets when it felt confident...

Well I think that would be great. 

Oh indeed... couple years.

As far as I can tell Frogboy's least favorite aspect of GC is combat... (okay... maybe the economic wheel of days past lol) to the point where I often detect a hint of scorn over any suggestion of deeper combat mechanics (manually controlled tactical combat). I get the impression that somehow the tactical combat of Fallen Enchantress (elemental) series must have caused a great deal of pain and misery for him or others, so now he's just burdened with game dev/CEO PTSD lol.

He's always been pretty clear that he prefers the civilization with the greater overall strategic advantage win on the battlefield. So weapon selection, tech choices, planet choices, industrial capacity... etc.

Which is fine. No one should seriously be trying to make GC into a tactical micro-managers haven... play StarCraft or Sins of a Solar Empire for that... but we should have at least a decent "sanity pass" on combat since the tech tree is getting completely overhauled.

True--to a point. I was in the process of writing a lengthy post (longer than what follows) about how hard it would be to program "basic strategies" that are anything more than arbitrary.

Whenever I see a dev journal or some indication from Stardock about a new feature in the game, one of my first thoughts is, will the AI be able to use it as well as the human players. Making it possible for people to do things--giving them more options--that is easy. Making the computer use those options well... not so easy. Think about how mercenaries are barely used (and if used, not used well) by the AI. Think about the AI using government ships to explore when they should be buffing planets. It's easy for us to look at the ship and say, "Yeah, I'll station that here." The AI is like, "What the heck is this for? I guess I'll send it out exploring."

I'm not going to profess to know a ton about AI programming--I do know enough to know that doing it right (e.g., making the AI respond to the current circumstances of the game in a meaningful way, using resources like ships most effectively, etc.) isn't easy.

I don't doubt Brad and the dev team's ability to make it work given sufficient time. But I do not expect that this is a priority and that they have the will to make it happen. Maybe I'm wrong (about the will--not the ability), and I hope so.

All that said--and back to topic, I would love to see the dev team invest the time to provide us more options for strategic ship design and make the AI able to take full advantage of such changes. And to your point, Gauntlet:

I agree. This is a good time to do it. With a revamp of the tech tree, different options could be given to make ship design more meaningful and diverse.

Four out of the eight suggestions you give above, Gauntlet, are moddable (which you acknowledge)--but again, not sure how the AI would deal with components having both pluses and minuses. And the more important changes, in my opinion, are your points #4, #5, and #6.

If the dev team does nothing else, I hope they make ship roles more meaningful and fix the OP citizen-related tactics that human players can exploit but that the AI doesn't.

Certainly the AI stuff is beyond me. You guys get the gist of what I'm getting at and seem to agree. Woot.

In regards to modability though... and forgetting the AI... it's been a while, but I think nearly all of my ideas are moddable. True... there may be unintended consequences... but I think they can be done.

The big one I remember having trouble with playing with it in the past was ship roles? Or am I mistaken?

Oh and I bet Carriers can't be done...

as for the AI, I'm by no means qualified to talk of it... but I sorta suspect a system of ship design "styles" could be built, and then you could assign a style to each race. Sort of like Sins of a Solar Empire where you could assign personalities to the AI.

So for example perhaps we assign "Aggressive Fleets" to the Drengin. Aggressive fleet designs are using a set of blueprints that favor kinetic weapons, thrusters, and repair, and generally eschew defenses.

etc. 

It would obviously be a big downgrade in the AIs ability to respond and adapt to their enemies, but it might be easier to program them to develop coherent fleets and strategies. Sure... 1v1 you'll know exactly how to counter the Drengin... but if there are say ... 5 styles, and you have 10 opponents, you'll be hardpressed to customize your navy 10 times to perfectly counter every opponent. Perhaps then also add a degree of randomness to it all... such as "choose random fleet style" for each race at the beginning of the game.

Again... much less adaptable, not really an AI so much as a sort of scripted set... but in aggregate it might actually be more interesting to play against. Dunno. Just thinking aloud.

"but we should have at least a decent "sanity pass" on combat since the tech tree is getting completely overhauled."...Hear. hear! That would be a start, researching technology that actually makes a difference in a battle, outside of the bigger\more is better.