Ok, this is a semi-complicated question, so I will explain it 2 ways...is it possible to have expanded upgrade paths?...like unit A upgrades to unit B...Unit B can be upgraded to unit C, which can be reverse upgraded to unit B or A(not both, but either one)

in practice, I want to make Horse lines have options...unit A being a unbarded, free running horse...unit B being a lightly saddled trained horse, and Unit C being a heavily armored warlike horse...
the way I see it, that way you could upgrade the "fast" horse(extra movement for lower Off/Def) to a war horse(lower mv but elevated Att/Def) during war time, but "take the armor off" for a faster movement during peace time...

also to make archers be off or def...and having the option of changing which they are....

Just an idea, that Im not sure how to work into a test at the moment, but I wanna try this in my Narnia mod...can anyone run a test on this idea for me?(my comp wont run Civ 3 at the moment...long story)...

thanx in advance...

hh the question is: will all units be buildable or will no unit be buildable (cause they are all obsolete)....
Good question. Also how ist the upgradecost callculated if the new unit is cheaper than te old one? will the costs be 0 or can you even gain some money....

You can't have a loop in the unit-line. The editor forbids it.
A->B->C->A : Can't do.

And if you'd use a copy of A, A', it wouldn't work.

A->B->C->A' ; The game would upgrade A to A' directly. It doesn't stop at each upgrade.

speaking of unit ideas, i'm messing with a basic scenario, whre there is 3 civs, one is yours, one is "evil" and one is "good".
depending on which one you want to attack, you get a different unit upgrade. the way it works is have several resources, no prequiste, on every second city.

you start off with a base unit, and the upgrade path goes as follows:
if you attack the bad-guys:
base-good1-good2-good3-good4-etc..

if you attack the good guys it goes:
base-bad1-bad2-bad3-bad4-etc..

the way it works is by having all the advancements require resources.
so the good cities go like so:
no resource-bad1-no resource-bad2-no resource-bad3-etc..

and for bad it goes:
no resource-good1-no resource-good2-no resource-good3-etc..

this way, you can upgrade your base unit to be good of evil.
if anyone wants me to explain better, just ask.
and sorry for the slight thread jacking..

Supa...that helped a bit...but to be exact, is this possible?...A --> B <--> C

where B and C are available at the same time, and A is rendered obsolete...oh and to answer the first question...a would be cheaper, but B & C cost the same

Well, in Civ-3, you can only upgrades to 1 unit, not to have the choice between 2.

And if you mean A->B->C->B, it's the same problem as A-B-C-A, it makes a loop.

bummer...oh well...would have been nice..

Thanx for the info Supa...saved me much time...

Unit B can be upgraded to unit C, which can be reverse upgraded to unit B or A(not both, but either one)
Yes, LotM adopted this strategy at one point. It resulted in a nice little game-freezing infinite loop. :D