New Discovery? Costless Units!

klesh · March 8, 2002, 22:40

Greetings again all,

Whilst fiddling with some values of units today, I made what could be a very interesting discovery. I do not know if this has been seen before, but it resembles the odd unit movement value phenomenon being discussed here. Perhaps William Keenan or someone has already figured this out. Perhaps not...

What I did was to mistakingly set the cost of a unit to 148. I just forgot to delete the 8 when changing the cost to 14. Well, to my surprise it resulted in the wierdest thing happening... the unit in question had a NONE listed as the cost! There was no shield box to be filled in, and of course any city or specific Civ can produce any unit at no cost to them! It would just require a dedicated ultra-expensive unit slot.

This will be good for scenarios where you want a very good unit, or lots of units, to be built from a worthless city or a city that shouldn't be of value when captured. No need to make city improvements extra cheap so the player wont sell them off etc. Many unique uses for this I believe. I havent really tested it much, I don't know if 148 is the magic number or what, but here are 2 screenies to show you what I am talking about. Try it out!

And if this is a new discovery, then it has my ™ on it!

-FMK.

klesh · March 8, 2002, 22:41

And here is a shot of Berlin making the cheapest Konigstigers known to man!

techumseh · March 8, 2002, 23:30

I'm impressed. Good work.

ravagon · March 8, 2002, 23:35

Bah. I would have replied first but the bleeping server cut me off.

Does it actually work in practice (do you get a unit each turn? - even if a city is producing no shields) or is it just a graphical thing?

Also - What's the bribe price for a zero cost unit?

Very interesting indeed

DarthVeda · March 9, 2002, 01:14

Makes me wonder what the other fields do with ludicrously high values?

The unit type slot...
The defense slot... (nuclear?)
The attack slot... (nuclear?)
The hitpoint slot...
The firepower slot...

Am I missing any?

DarthVeda · March 9, 2002, 01:17

Although, couldn't you just set the production to 0 and achieve the same effect?

ravagon · March 9, 2002, 01:31

Quote:

Originally posted by DarthVeda
Makes me wonder what the other fields do with ludicrously high values?

The unit type slot...
The defense slot... (nuclear?)
The attack slot... (nuclear?)
The hitpoint slot...
The firepower slot...

Am I missing any?

I just started thinking the same thing after reading that quote from WK in FMK's other thread.

Move slot
Transport slot
Domain (?) slot - I've tried values up to about 9 or so and all of them crashed but I never thought to try anything that much higher...

I'm off to have a play, er, conduct a rigorous scientific investigation.

MagyarCrusader · March 9, 2002, 01:33

I could have had uses for that back in my scen creation days... Damn you FMK for waiting so long to tell me!

j/k Good work!

klesh · March 9, 2002, 02:18

Hey everybody,

Girlfriend Shanghaied me tonite soon after making this thread. Needless to say I haven't had any time to work on this (and I am quite drunk at the moment to boot).

Quote:

Does it actually work in practice (do you get a unit each turn? - even if a city is producing no shields) or is it just a graphical thing?

Take a closer look to that screenie of Berlin. The city is still producing 41 shields, its just that the unit costs zero.

Quote:

Also - What's the bribe price for a zero cost unit?

Again, I'll need to play around a bit to see if there is anything strange about the units built this way.

Quote:

Although, couldn't you just set the production to 0 and achieve the same effect?

Yeah, I suppose you could.

I was just startled by this and didn't even think of it. I'll try that too. Perhaps entering zero for a cost might just default to 10?

Quote:

Damn you FMK for waiting so long to tell me!

Damn me for taking so long to stumble upon this!

I dont know, maybe this is useless. I'll have to fiddle more with this to see whats up. Maybe the AI still sees the cost as 148 and will refuse to buy such rediculous units...

-FMK.

klesh · March 9, 2002, 02:26

Ran a quick check here, and making a unit 0 cost in fact does default it's cost to 10.

-FMK.

Henrik · March 9, 2002, 04:13

Quote:

Originally posted by Field Marshal Klesh
Ran a quick check here, and making a unit 0 cost in fact does default it's cost to 10.

No it doesnt check again

The shield row gets a little bigger but the cost is still 0!
Atleast thats how it is for improvements.

Xin Yu · March 9, 2002, 05:14

I suspected a while ago that setting too big a shield box would give a negative cost (you rush buy a unit and gain money from it). Perhaps you can test it as well.

Paul Hanson · March 9, 2002, 06:56

IIRC, this sort of thing happens on the USA 2010 scenario that comes with FW. Under the right circumstances, rushbuilding a Cyborg unit results in you receiving money.

our_man · March 9, 2002, 07:22

Paul, Xin, this does indeed happen once a unit costs over 180 shields in FW. I think Microprose mentioned this in the manual, but they managed to fix the bug under MGE.

A classic example of this is playing as the Spanish in Jay Bee's War of Cuba. The weird thing about this is that there appears to be no discernable pattern to when you can buy a unit for a negative amount of money. For example, one turn a unit could cost you 220 shields and to buy it would give you money - the next turn it might have gone down to 215 shields and it'll cost you an absolute fortune to rush-buy. It's weird.

Paul Hanson · March 9, 2002, 12:55

You're absolutely right. My friend who owned FW could get several thousand gold a turn by simply rushbuilding Cyborgs on USA 2010, whilst MGE-owning me couldn't get it to work.

And yes, the FW manual warns against setting build costs higher than 180 shields.

DarthVeda · March 9, 2002, 14:34

So what's the max shield cost in MGE/ToT?

250?

klesh · March 9, 2002, 14:51

I am gonna have to have some time to play around and get some findings. Beautiful day here, and the gf wont stand for me sitting in front of the pc. I will kepp testing though...

Henrik, yes it does... for units anyway. Entering 0 for a cost and looking at the shieldbox for the unit, it was a standard depth 10 shield unit.

All of this is being done with MGE as that is all I have. You guys will have to test the ToT and FW ones...

I'll also check on if you get money or something from building these units. More to come....

-FMK.

klesh · March 9, 2002, 15:37

Well I snuck some time for another quick test. The results are promising indeed.

When set to build these costless units any city really can build them. It isnt some graphic screw up where the units really cost 10 shields. A city that made 2 shields per turn could pump out these units.

Also, even rioting cities, which should have zero production anyway, can still pump out these units.

The units are supported as usual from the home city. Which makes me think that in the fanatic slot under a fundy gov., this technique could be deadly making free support/free build units from small little 'base' cities off out in nowhere or somesuch.

Now here is something strange indeed, when using the edit city function in cheat mode to reset cities's shield accumulation to zero, I found that cities which had just made one of these units had accumulation in the negative(-521 shields)! So I let those cities continue. They built another unit the next turn no problem. As I look now after the next turn... all the cities' progress is back to zero... no negative values anymore. Obviously, more in depth testing is needed. I would also like to see if the AI will choose these units to build. I will make their other stats (at/def) very appealing so they will want the unit. I would like to see if they are turned off to building it at all or something.

I also want to see how this effects the AI's use of cruise missile units, as it is commonly know they use a cost anaylsis to judge whether to send out a missle to strike.

Many things to test, and no time to do it right now. Argh!

-FMK.

hardjoy · March 9, 2002, 23:17

Very interesting discoveries, FMK! Keep up the good work!

I will be following the test results closely

...perhaps even do my own bits of testing! intriguing to say the least..

ravagon · March 9, 2002, 23:48

I did some playing too and got some rather odd results.
Firstly I was NOT able to reproduce the screen with the NONE unit cost. Still don't know about this one. Costs were always negative.

Unit costs of zero default to 10 shields (although it doesn't do this for improvements strangely enough where 0=0) and follows the usual pattern up to 127 (1270 shields)
At 128 (2^7) it flips to -1280 which rounds up to give the zero cost unit and thereafter continues increasing. ie: 129 --> -1270 etc, up to 200 which seems to be the max and has a shield cost of -560 (IIRC). Hence all unit costs above 127 are 0.

[This flip happens in the terrain resources too btw at the same point. 127 = 127 shields. 128 = -1280 (rounds up to 0 production)]

It works this way for the AI too, even though AI cities seem to produce a full shield box every turn (Graphical anomaly?)

An AI oddity that showed up however was a strong tendency to NOT attack with zero-cost units. I was at war with them and cheated in a horde of spies to keep an eye on their city production from turn to turn and my spies/other units were never attacked/expelled. This went on until I made peace. The AI then began expelling spies like crazy before sneak attacking with its zero-cost units on both my spies and other units but only for this turn.
The next turn business as usual. ie: His units just moving around not attacking spies or others in open terrain right next to his cities.
[Incidentally I was using the Jihad scenario and the fundamentalist and horseman slots to test all this]

One interesting thing that came to light was the ability to rush-build these zero-cost units. Cost was 0 gold and it produced the negative 1280 (using the production cost = 128) shields required to build the unit (although this didn't show up in the production box).
If you the changed the production queue to something else it showed a much much higher number of turns to build the new something due to the negative shield deficit that had to be "worked off" before applying shields to actually build it.

This might be ideal if somebody were designing a scenario and wished for cities to be unable to build anything for a number of turns before having their production resume at full strength.
It is still very cumbersome though as the minimum shield deficit seems to be 560 (from rush building a unit with a cost of 200) which is quite sizable.
All of this is completely irrelevant however if civtweak can set a cities shield production to a negative value (which I forgot to check

)

[Edit: Actually, rereading FMK's post, he covered most of this anyway

]

DarthVeda · March 10, 2002, 00:25

Oooh.... that will be useful...

Goingonit · March 10, 2002, 09:39

Neat.

IMO, the AI douesn't take cost into account when building units.

Boco · March 10, 2002, 22:52

To make a 'slow road' terrain, I had set the movecost to 205 (Road bonus =25, set to >10 to take advantage of WK's fractional movement math). Civ2 behaves oddly but reproducibly with these settings. Regular roads (and rivers) cost 1/10 mf; the new 'slow road' costs 2/10mf.

Here's the kicker: the Civ2 terrain editor squawks when it encounters an out-of-range variable. I was tweaking the 'slow road' terrain image via the Editor menu in Civ2, when it spotted the movecost was set out of range. It did me the 'favor' of resetting the movecost to 0 in the rules.txt. I wouldn't be surprised if this were not an isolated incident.

DarthVeda · March 11, 2002, 02:01

Watch out for the civ2 editors period. They are far too buggy to be trusted by any serious scenario creator.

I recall several incidents where it changes the name of your civ to that of a resource and vice versa.

Heresson · March 11, 2002, 09:57

Nice discovery, I'm sure it'll be usefull in making some computer-played civ properly dangerous for You. I don't see any use for it
in human-played civ though; most of scns are enough easy already.

Boco · September 6, 2002, 16:34

*Bump*

Has anyone used costless units in a scenario?

William Keenan · September 6, 2002, 17:54

Greetings all. Its been awhile.

I think I can help shed some light on this topic. Most Civ unit values are stored as signed byte integers (-128 to 127). This conserves computer memory but produces odd results when larger than expected values are inserted.

More in a moment .....

Goingonit · September 6, 2002, 19:48

That gives me a new idea...

Ravagon was suggesting in the engineer/city-production thread that a Xin Yu or similar strategist could disband a city by selling its city walls and causing it to be destroyed by combat. Well, that would be a lot more balanced strategically if the city walls had negative cost! (and thus cost money to sell!) I'll test this, but it sounds practical and useful.

William Keenan · September 6, 2002, 19:50

..... back.

Computers do math using a base 16 system (hexidecimal), not the base 10 system (Decimal) we use.

One byte is 2 hexidecimal digits: 00 to FF

Decimal values: 0 to 255.

When a byte is signed decimal values are different
00 to 7F hex is 0 to 127 decimal and 80 to FF hex is -128 to -1 decimal. See Ravagons explaination above.

Civ2 uses signed bytes in unit values. It follows that a unit cost of 255 in the rules.txt is converted to a hex value of FF which to the computer is -1. Therefore the unit build cost would be (-1*10)=-10.

A city producing only one shield per turn will produce this unit evey turn because the total accumulated shield production of 1 is equal to or greater than the unit cost of -10.

Theoretically, a city with a -9 shield production would also produce the unit every turn. But a city with a -11 production would never produce the unit.

Quote:

Originally posted by DarthVeda
So what's the max shield cost in MGE/ToT?

250?

The highest possible positive number should be 1270.

Goingonit · September 6, 2002, 20:02

Darn, it turns out that this doesn't work. Improvements, at least, have positive and accurate costs to 255, and them positive but inaccurate costs thereafter (the cost is equal to the set cost mod 256, which leads me to think that the cost is stored as an unsigned byte.)