Warlords: inconsistent tech costs

[Bushface]

At one stage, I was offered for research :-
Nationalism, costing 2898 flasks, taking 7 turns
Education, 2898, in 8 turns
Printing Press, 2576, in 7 turns
Astronomy, 3220, in 11 turns
Gunpowder, 1932, in 5 turns.

I had a small amount of carryover, which I reckoned to be about 144 flasks (by measurement on the Research bar).
I tried reloading and selecting each of these techs, and found that after one turn the amount of research had risen to 510 flasks for Education, Press and Gunpowder, to 595 for Nationalism, and only 425 for Astronomy. Apart from the change of tech I made no other changes, so why did the amount of research produced vary with the tech choice ? Moreover, on going for Astronomy and Education the further research time dropped, in one turn, by 2 turns, that is to 9 and 6 respectively.
If I produce 387 flasks per turn, the minimum to get Gunpowder in 5 turns, then that amount of research ought to get Astronomy in 9 turns, not 11.

Steps to reproduce - look at the times to research any two or more techs and compare the research-per-turn required.

Yes, research times can be affected by progress by other civs. But in this case I was the clear tech leader.

 

[Commander Bello]

As far as I remember, the calculation rules for the costs of technologies are quite complicated.
As you correctly pointed out, it depends on how many other nations which you know, know about that tech. But it depends as well on how many of the previous technologies you know.
If there are 2 technologies A and B leading to tech X, and you know only A, then X will be more expensive as if you would know both techs.

There was somewhere an early article explaining the calculations in more detail, either here or over at Apolyton. You may want to make use of the search functionality.

 

[ori]

here you are

Calculating the Prerequisites modifier

1) Start with 1. If the technology does NOT have a minimum requirement (i.e., the starting techs = Fishing, The Wheel, Agriculture, Hunting, Mysticism, Mining), then use 1 AS the modifier.

2) Add 0.2 to 1) if a Technology has a MINIMUM Requirement that the player has met. Note: Even if a tech has MANY MANDATORY PREREQUISITES, it will still only give you a boost of 1.2 because you MUST have all those prerequisites to research the tech. (IOW, the minimum requirement IS all of those prerequisites.)

3) Add 0.2 to 2) for EACH ADDITIONAL OPTIONAL Prerequisite that the player has met.

Requirements modifier = 1 + (0.2 * MINIMUM Req. met) + (0.2 * # of Optional Prereq. met)

 

[Bushface]

I still don't get it. A bit later in the game, I was offered Astronomy in 5 turns or Mil. Trad. in 4 turns. Each costs 3220 flasks; each has two immediate prerequisites (Optics and Calendar, Nationalism and Music) which, obviously, I have; and as I have all the Ancient, Classical and Medieval techs plus Press, Education and Parts then I clearly have every possible prerequisite for the two techs in question. Am I getting a concealed bonus for the other techs, or am I being penalised for Astronomy ? How far back does one go in counting optional precursors (being unnecessary, they can't be prerequisites) ?
Rival civs can be discounted. I could trade Nationalism with Ramesses and Optics with Mansa (but shan't, as they have nothing to offer); Saladin and Napoleon are well behind, and spending much time squabbling with axemen and archers over Marseilles, a conflict watched by one of my Scouts; Julius is lurking near the Arctic and has just asked me to give him Machinery - fat chance, mate !

 

[ori]

I still don't get it. A bit later in the game, I was offered Astronomy in 5 turns or Mil. Trad. in 4 turns. Each costs 3220 flasks; each has two immediate prerequisites (Optics and Calendar, Nationalism and Music) which, obviously, I have; and as I have all the Ancient, Classical and Medieval techs plus Press, Education and Parts then I clearly have every possible prerequisite for the two techs in question. Am I getting a concealed bonus for the other techs, or am I being penalised for Astronomy ? How far back does one go in counting optional precursors (being unnecessary, they can't be prerequisites) ?
Rival civs can be discounted. I could trade Nationalism with Ramesses and Optics with Mansa (but shan't, as they have nothing to offer); Saladin and Napoleon are well behind, and spending much time squabbling with axemen and archers over Marseilles, a conflict watched by one of my Scouts; Julius is lurking near the Arctic and has just asked me to give him Machinery - fat chance, mate !

I found the problem
The quote I gave above says "Minimum" and "Optional" In fact those are:
"ANDPrereq" and "ORPrereq"
Now you you nead all ANDPrereq's AND atleast one ORPrereq. Any ORPrereq will give you the .2 modifier.
For whatever reason Programmers have given Astronomy 2 ANDPrereq's (Calender and Optics) and Military Tradition 1 ANDPrereq (Music) and 1 ORPrereq (Nationalism).
The endresult is the same (you need two techs and there is just on possible path) but you get the .2 modifier for having a ORPrereq for Military Tradition
I'd classify this as a minor bug in the xml - but maybe there is some great plan I don't see

Edit: this is already in the Vanilla xml...

 

[Fachy]

They're not flasks, they're beakers ><

 

[mrt144]

They're not flasks, they're beakers ><

wah!