First, Thanks to ALL ! This has been a great thread, with alot of ideas that have been really fun to play with. I think I almost enjoy playing WITH the game more than playing it...
It seems that in order for any real, meaningful change in the game to take place, both a balance and an adjustment to the speed of discovery of technologies must take place.
Alot of threads about tech costs are here, which definitely changes the face of the game. I feel this is one of the necessities, but another way to achieve a similar result is to look at how the game uses
prerequisite techs... not re-writing the tech tree, but changing how the game recognizes it's OK for you start researching the next tech up the tree.
One thing I REALLY dislike, which has been mentioned here numerous times, is getting to an era ( medieval ), and finding out another civ has riflemen already. Changing the cost of techs may prolong this, but won't address how the civ got there so fast ahead of you. Because both the AI and the Human player beeline for specific "pet" techs, the current open tech tree allows for onesided, lopsided and strange occurences in the Civ 4 world of technology. By changing how prereq techs work, we can limit this, allowing for those matched, era specific elongated military conflicts we all seem to long for.
In the tech tree, techs that require a tech, ( prereq ) have an AND or an OR modifier in the XML file.
An example: Monarchy
In the original tech tree, one can get to monarchy by researching priesthood OR monotheism. There isn't an AND modifier at all. This means a one sided approach to the tech is possible, allowing you ( or the AI ) to beeline one side of the tech tree and completely ignore the other. The same is true for alot of the game changing techs as well, ie Military Tradition, Assembly Line, Gunpowder...
While this creates what some would call "strategy", I just found it far to easy to beeline, which in my book makes it "manipulation". Get to the key techs and dominate... I think it also makes you "tip your hand", so to speak. Your agenda is revealed in the techs you choose, as well as the agenda of the AI civs. I think the AI already have a disadvantage due to the traits they're given. You know, as a human player, that Montezuma is going to war, and as your closest neighbor, you'll follow a military strategy, at least until he's gone. ( I think that that's a whole other thread, so I'll end it here...) Suffice to say that changing the prereqs forces the AI to utilize techs outside their traits, which makes them all the more formidable.( I would think this to also be the case in a MP game, where knowing the beelines would allow you many clues of another players intentions...)
In keeping with the thread, I sought to balance the techs out, create a more level playing field ( not only for you but for the AI ), and make it so a player was rewarded for a sound scientific strategy, wether they be human or not.
To do this, I changed every single OR prereq tech to an AND prereq tech. Instead of choosing one tech to research before Monarchy, you now have to research them both. In the grander scheme of things, it means you MUST run the whole tech tree. Not only do you have to decide what will really benefit you now... you have to figure out what you're going to do while your researching that tech you always used to let go, because it was obsolite before you got it...
I found I had to totally change how I had to play, and a focus on tech was now a real necessity. In addition, I found the eras to last that little bit longer due to having all of the players going back in the tree to those techs they usually didn't research. This leads to what we're all looking for, extended time with the different unit types. ( I also played with tweaking costs, era's etc... which really allowed for prolonged action with the medieval era. I don't go far past 500 turns for a game, and still had over 100 turns with to play with these units...
A TANGENT: To suit my own personal tastes, I added some prereqs for the era changers in order to lengthen the time with Cavalry, Riflemen and Cannon, and then again to Assmembly Line so I could have Machine Gunners, Infantry and Artillery together for a time. I basically required techs from the other side of the tree that would be required in the real world if you think about it.
An example would be the Assembly Line tech. I made Railroad, Steel, and Steam Power required techs. Henry Fords first assembly line was after we had the railroads criss-crossing the whole country... In my mind, requiring these just puts the tech in the timeline where it should be in relation to history.
Negatives....
I play 500-550 turn games, so alot of what I put here is related to that...
1) There is still not enough time with the Cavalry/Rifleman era for my tastes, even though historically you could say it's acurate due to their real time in the real world... I run around 70 turns in each of the last 4 eras, 3,2,1,1 year per turn respectively... and it still seems like I'm into Machine guns and Infantry way too quickly. ( Machine gunners are available with Assembly Line ) If I wanted to go to 600 or 700 turns, I could change my years per turn to 1 and expand this era a bit. It's nice to have that option...
2) The AI still blow you away in the early game, especially with tech trading allowed. I had never been one for dedicated cities, but a science city is a MUST if you want to keep up with the AI. Once past Guilds, my style of play comes into its own, and I'm able to get some techs first, which allow me to trade pretty well for awhile. Once into Rifleman, I usually break away from the pack, and the research issue is nonexistant.
3) The inevitable tech every 3-5 turns... Because I play shorter games, and had a reformat of the hard drive I've been playing with the original tech costs. In the past, I raised tech prices by 10% an era from renaissance on, and this worked pretty well. Now that my computer is back and healthy, I'm going to delve more into Doskei's ideas of individual tech pricing....
4) Sometimes you just don't have a whole lot to choose from. In the past, you'd have 8 or 9 techs to go for. You have that now in the early game, but as the game progresses, the stop gaps on the key techs ( because they have additional prereqs ) can lead you to some times of 3 or 4 choices. To me, it just means I'm doing OK, and that I'm near the end of an era. To some, they may want to have some more choice, even if it means you're attacking Machine guns with knights.... Note that this has more to do with the TANGENT above than with the original tech tree...
All in all, It's a little work, but I believe the result is well worth the time. By balancing out the tree in this way, the AI and the player must both deal with the same obsticles. The AI respond very well to this, as their tendancy to value strange or useless techs is minimized, while the human player now has to deal with the same strange and useless techs they'd otherwise beeline past. Combined with cost changes, wether they be tech specific or era specific, the change really comes life. Even with the shorter games that I tend to play, I have had many, many satisfying medieval battles over many, many turns.
Tim aka....antracer