Before we start, let's us all UNLEARN everything we know about 4X It does not have to be muliplayer, it does not have to be symmetric, it does not need to be balanced, it does not even need to have other entities than the player (like player vs environment). Basically free yourself from all/most of traditional restrictions Also feel free to assume any settings, game rules, mood, etc.

The question is how to make warfare goals in space 4X? Typically there is only one goal, use fleets to conquer or defend own planets. So, basically everything revolves around planets. It results in the "take over all planets" goal, which is kind of unfun in many cases

So, I was thinking on other approaches to space warfare goals. Maybe something like "you need to defeat enemy fleet to show them who is the boss and therefore get a tribute from them", or maybe like "there is a pirates threat and you pursue to destroy their bases (without taking their planets) to assure safety of own trade routes/planets", something along those lines. Or maybe something completely different.

How is travel achieved in your setting?  Is there FTL, or 'jump gates', or just traditional (but presumably very fast) travel?

A goal might be to control/block/open whatever constitutes means of travel -- holding gates, or blocking choke points, creating choke points by blocking open space, etc.  Maybe to secure your own ability to travel, or perhaps to restrict the travel of others (pirates, your own subjects, whatever).

Similarly, perhaps the goal is to control or defend non-planetary resources.  Perhaps asteroid belts, nebulae, etc. are valuable because they're easier to exploit than the materials found on planets.  Perhaps pirates or rogue groups try to gain access to these resources and undermine your rule, or segments of your own citizenry can't be trusted.  Maybe you need to balance this with more traditional goals - is it more valuable to keep the asteroids being used to build a new fleet, or to keep hold of a planet that's under attack?

Whatever goals are added should provide interesting choices for the player.

12 minutes ago, jbadams said:

How is travel achieved in your setting?  Is there FTL, or 'jump gates', or just traditional (but presumably very fast) travel?

A goal might be to control/block/open whatever constitutes means of travel -- holding gates, or blocking choke points, creating choke points by blocking open space, etc.  Maybe to secure your own ability to travel, or perhaps to restrict the travel of others (pirates, your own subjects, whatever).

Whichever you prefer. It's just a discussion and I wanted to try to find new ways to implement it rather to include it in my game right away Personally I prefer starlanes mechanic since it provides natural chokepoints. Anyway, assume whichever you like.

BTW, it was interestingly done in Chapter Master. Technically you owned all/most planets you see on the map, but most of them were infested by various aliens so you were jumping around trying to subdue infestation on your planets. The nice thing was that you controled the same number of planets in the late game as in the early game. But it had no "borders" since those alien infestations were almost everywhere.

I imagine there would be similar strategic goals to regular warfare.

For an attacker at the most basic level there are three options:  Annihilation so they're completely defeated, attrition so they lose enough things they get worn down enough to do what they wanted, and exhaustion like blockades until they eventually submit.  A defender has an additional option of survival by attrition, keep on not losing until eventually the other side is sufficiently worn out and stops spending resources on the war.

Games usually focus on direct annihilation or large battles in the hope of attrition.  Some strategy games may use that for a while, although I think it is mostly a tool to hold one player back while the opponent amasses an army sufficient for annihilation.

As for specific objectives, I think they lead to basically the same premise.

* Capture and return, with resources, information, prototypes, key people, and whatever else. Could be accomplished through secrecy and espionage, or a full-on attack team.  The "capture" could instead be leaving something behind, or stealing/growing/harvesting resources and bringing them back.  Get in, do something, get out.

* Capture and hold, often with key infrastructure.  Again you could fight your way in, or slip in unnoticed. Get in, stay in until others arrive.

* Search and destroy, often with key resources, infrastructure, and key people.  Similarly as above, can be covert.  Get in, sufficiently break stuff.

* Blockade, prevent infiltration. 

I don't think anything fundamentally changes with a "revolves around planets" game style.

In real life, interplanetary and interstellar warfare probably won't be about what happens on the ground.  The biggest thing is getting stuff from one planet to another planet, or intercepting things before they arrive.  If you've got enough power for rapid interstellar travel then you've got enough power to destroy a planet.  "Nuke it from orbit" is a viable strategy as far as we can see, and throwing a bunch of big space rocks could be enough.  A few small space rocks -- maybe the size of a house -- could level a small city.  Somewhat larger space rocks, maybe a few hundred feet around, could decimate a wide metro area.  An even larger space rock could be an event like a dinosaur-killing meteor that would transform the planet so much the warfare stops being significant.  An attacker could throw space rocks from any direction at any distance.  

At their simplest, an attacker can just fly an interstellar ship at the planet and not hit the brakes.  As long as it hits the planet fast enough, the planet gets destroyed.  Even if the defender breaks up the ship, if the debris hits hard enough the planet still gets sufficiently destroyed.