I ended up with multiple sides on the same battle mechanic :) Had to do it, no choice :)

So, now I wonder how to handle this monstrousity?

I mean especially visually. Originally, I planned to have two sides, on has ships on the left part of the screen, second on the right and they tidely shoot at each other :) But now... How I'm supposed to visualise like 5 sides in one battle (one of these being the player)?

Technical info:

- each side has several stacks (1-8 stacks typically) that represent one type of ship (but if you own two fleets in a battle you might end up with 2 stacks of Destroyers one for each fleet)

- there is an unspecified number of sides, but I think 5 sides per battle is the worst case scenario (still I would like it being able to at least handle, no matter in what unappealing/lame way, more sides)

You can use polygons to abstract the visualization:

3 sides: triangle

4 sides: quad

5 sides: pentagon

... hexagon... you got it

then put one fleet on each edge of the figure. It's pretty much the same abstraction of having 2 fleets one on the left and one on the right

Depending on how many ships are involved, I'm inclined to agree with Arka: arrange the various fleets equidistantly on the circumference of a circle (which produces the polygons that Arka describes).

Otherwise, how does combat play out? Is it automatic? Is the user required to click on ships, or manoeuvre them, or designate targets? Do all sides (potentially) attack all other sides, or is combat resolved in some particular order?

Hmm... Thinking about that last point, If combat is turn-based (whether automatic or not), then another idea might be this: Display the various fleets in a list to one side. When a fleet's turn comes up, that fleet is displayed at larger scale in the main section of the view, near one of the edges. A target fleet is selected (again, whether automatically or not), and that fleet appears on the opposite side of the main view. (The result is thus, essentially, your extant two-fleet arrangement, but with a list sitting on one side of the screen.) The turn then resolves as per usual. The next turn comes up, and the next fleet takes the place of the previous, another target fleet is selected, and so on.

Depending on how many ships are involved

Each side has several stacks (1-8 stacks typically).

Otherwise, how does combat play out? Is it automatic? Is the user required to click on ships, or manoeuvre them, or designate targets? Do all sides (potentially) attack all other sides, or is combat resolved in some particular order?

Hrm, writing about pie slices has made me hungry...

This is turn based, right?

If there will still be two sides even though there are 5 parties involved (which is more likely than coincidential warzone of other parties) , left-right style makes more sense imo.

If there will be polygonal visualization, I think you need to include strategy elements giving that choice a depth (like one edge of player vs 4 edges of enemy gives serious problem about flanking)

If there will still be two sides even though there are 5 parties involved (which is more likely than coincidential warzone of other parties) , left-right style makes more sense imo.

No, everyone hates everyone. Some aliens might hate other aliens more but overall in the end they want to be the last man/alien standing (to grab the planet they all were fighting for).

Sticking with the 'pie slice' model for a moment, it might be reasonable to only allow each fleet to attack adjoining slices. Once a fleet is eliminated, that pie slice is removed, and you can now attack the newly adjacent fleet instead.

If the battle is turn based and the display is abstract (stacks hurting other stacks) rather than spatial (ships aiming, shooting, moving into and out of range) you can display the stacks of the active faction in the middle and all enemy stacks around the borders of the view, with arrows or the like connecting attacking and attacked stacks. The enemies can be sorted conventionally (e.g. factions in alphabetical order by name clockwise from the upper left corner, stacks of each faction by size and age), the active stacks could be sorted according to graph layout heuristics (e.g. in a circle, about in front of the enemy they are attacking). You could then display nice animations of moving stacks between turns.

You might also go further with graph layout approaches, for example starting with all stacks around the border as above and pulling together two stacks when one attacks the other, resulting in stacks drifting close to their specific enemies over the course of multiple turns without large movements.