I think its just maintenance

although this is a good question

I remember this discussion. Even though Blair already answered (he's a fast one, that), it basically boils down to the number of planets you have.

it's a good and realistic system, but Blair's wrong about one thing though. it's ALWAYS good to have a massive fleet

that is where you are wrong though....if its making you lose a alot of money just to keep the fleet in exhistance through just maintenance...then its not cost effective to keep such a large fleet unless you are actually making progress with that fleet. militarily...large fleets are loved....but economically.....they just arent warranted unless the end outcome is for the better in the near or immediate future.

yes, fighters hvae to be launced form a cap ship, but there is a limit to how many fighter 1 cap ship can carry

Maybe orbital buildings do have a maintainance cost. That way you coudln't spam labs.

I'd love to see a way to mothball a ship like in the real world.

You basically seal hatches, remove ammo and other supplies from the ship and give it a maintenance crew or even have one crew that takes care of 10 ships.

The US Navy has many ships mothballed, it's cheaper to refit a mothballed ship then it is to build a new one.

That would make having large fleets really cool, just mothball them in between wars. That way you don't have to recycle an old ship, this would really come in handy for capital ships.

That way you can have a cheaper maintenance cost when you don't need vast fleets.

Maybe there could be a ship storage orbit or something...It would be a good idea. However, restarting them should be time instensive and a decent cost, to prevent using them defensively.

That would make having large fleets really cool, just mothball them in between wars.

It's an RTS wargame, not an empire building game.
There is no "in between wars"

though the storage idea might sound strange, unfitting and unbalancing, it has been done before in RTS. I believe it was Empire Earth (correct me if i'm wrong) that you could build a Fortress to store units in. It could take 50 troops or 25 horsemen, which would not count towards your population cap while inside. They can't be removed from the fortress if that would exceed popcap. Also, it took some time to ungarrison them.

It's not such a bad idea, especially when using HUGE fleets, it pays to have a reserve, but then again, you risk slowing down the game.

There would have to be some kind of penatly for having more active than you can support. Maybe units firepower and health is degraded, or reasearch slows, or some combination of things to prevent that.

its a realized economic soft cap

aka, if you go over you start to lose money.

well... aside from losing your whole treasury and being completely incapable of repelling any sort of invasion, the excess ships might glow up.

I prefer the pop limit to be when malloc()/new() return NULL.