I've not heard of the AI building multiple ships per turn but I have heard of the AI being able to rush buy multiple buildings per turn and there's no real difference between being able to purchase buildings and being able to purchase ships.

This is a very old "bug" but it's just as easily considered a "documented feature". This should only be able to happen when you've done a save/reload during the same turn. You can avoid this effect by not saving and reloading so often however every time you do a reload you are allowing this possibility to occur.

IIRC what happens is that when you load a game the AI basically takes a production turn during which the AI could purchase buildings or ships or do anything else that doesn't involve ship movement. As long as the game is not then saved and reloaded prior to pressing end turn then everything operates normally. However if another save and reload occurs then previously purchased items become available and the AI gets another opportunity to purchase more items potentially from or on the same planets that have already "produced" an item this turn.

The bottom line is that this was decided to be not all that big of a deal and only really noticeable during the very early stages of the game where and AI could be able to produce both a factory as well as their manufacturing cap. Notethat the AI doesn't receive any extra turns worth of income and so while they may get the benefit of having a ship or building a turn or two earlier than you could, they can only accomplish this by dissipating their savings. The AI gets no similar advantage if using conventional production. It is possible for them to rush buy *and* produce a ship or building by conventional means they certainly can't produce more than one ship or one building per planet per turn with ordinary production.

Also AFAIK the AI never buys items on time and so, unlike the human player, the AI always pays top dollar for anything it rush buys which is some amount of compensation for being able to buy more than one thing at a time.

Income production is essentially global in that income produced anywhere is available to you to spend on any planet. So if you consider your planet that can produce an excess 2000 bc's of income that planet could support the building of a ship in it's own shipyard and also the building of a ship in another planets shipyard that might not have the excess income to otherwise do so.

However if you're talking about actual military production of a planet being 2000 MP's per turn (as opposed to 2000 BC's per turn of income) then that's another story. In that case if you were to build a 200 MP scout then you would have totally wasted 1800 MP's of production but not only that you still would have had to pay the 2000 BC's that those 2000 MP's of planetary production actually cost (minus half of whatever portion of that production was bonus production but that's just a detail).

There has long been a desire to have the ability to be able to either use the excess military production as described above by being able to build more than one ship at a time (after all it is the shipyard of an entire planet, it should be able to work on more than just a single scout at a time) or at the very least not charge someone the entire 2000 BC cost of using 2000 MP's of production to produce a ship that requires only 200 MP's of production.

I want to make sure that I've made the distinction between rush buying a ship or a building versus the cost of producing that same ship or building.

Basically the terms are used fairly interchangeably and so it's not always obvious what someone means. Even in the Ship Yard if you create a ship consisting of just a cargo hull then it lists the ship cost as 55 BC. Technically a cargo hull does not cost 55 BC, it really costs 55 MP's of military production however in normal operation it costs 55 BC's to use 55 MP's of military production so on that basis they are interchangeable. However in order to be able to actually produce such a ship in a single turn a planet must first have at least 55 MP's worth of factories on the planet.

Rush buying is different. It doesn't use any of the factory capacity of the planet instead it simply "throws money at the problem" to get the ship/building produced in single turn regardless of how little the planet could produce on it's own. To do this obviously should cost more than the cost of normal production.

The cargo hull example I used requires 55MP's of production which costs 55 BC's but if instead you rush buy the ship it actually costs 492 BC's instead of 55 BC's but requires no factories to do so. Hopefully this makes the distinction clear.

I forget the exact Rush Buy formula which I'm sure Sole Soul or Iztok could easily supply if either happens to stumble on this post.

The point is that even though what you're seeing may be a different issue than what I initially described it is in all likelihood some combination of Rush Buying along with normal production that is allowing the AI to "produce" more than one ship per planet per turn. It's highly doubtful that the AI is actually able to do this using only "normal" production. And although you can't do exactly the same thing you could do the equivalent by producing a ship at one planet in the normal method and "producing" a ship at another planet, perhaps one without much industry, by Rush Buying the ship.

The point is that Rush Buying involves extra inefficiencies over and above those of normal production and it's extremely doubtful that the AI could produce two ships on one planet in one turn without incurring those same inefficiencies that the human player would have to incur to do something similar.

If you were going after things like this I would be far more interested in getting rid of the global research/social/military production slider stuff along with focus. This results in far more inefficiency than just being able to build only one ship per planet. I mean why have these kinds of global levers at all? Why not have each planet produce everything that it's able to produce? If a planet has all research buildings and no factories why not simply allow it to "produce" the amount of research implied by the number of research buildings it has? What does some gigantic galaxy wide lever have to do with the capabilities of such a planet?

In the end it's merely a game mechanism and it really needs no basis whatsoever in realism. The bottom line is, is the overall system "workable" enough to be able to make a decent playing game? There is some balance needed between gross global control and direct individual control of each and every planet. Too much of either way is bad, however I suggest that what we have now is too global a mechanism with not enough individual control.

However, despite all its warts I believe GC2 to be one of the best TBS type games ever created. I would hope that in lieu of GC3 that things like this do in fact get addressed sooner or later.

The basic rush buy cost is trunc(cost^1.1)*6-I don't recall ever looking for the formulas for the other 3 rush buy options, but I believe the wiki has all 4, or rough approximations thereof.

I'm not sure that two ships can be produced per planet per turn, even with rush buying-I can't recall ever having tried it.

Actually, it was my understanding that at some point the game was patched so the AI no longer took an "extra turn", so to speak, but I can't remember when that was.

In short, I have no idea what might have caused that.  Nor have I personally witnessed it.

I have the latest versions and patches, and its really only as of late that I've noticed the multiple ships per turn phenomenomenomoly.

This is starting to generate some suggestions that might be useful for the next expansion.  Since there won't be a Galciv3 at this point, I'm creating a new post titled: "What would you like to see in the next expansion?" (After Twilight).