I'll edit whit the numbers later but I totally go for the civic first until I run into an hostile sovereign, then a little adventure to unlock more ressource. After all this, if a lot of shard near me, magic and after warfare. If hostile near me, Civic, warfare, adventure, magic and diplomacy.

Civ 4, Adventuring 4, Diplomacy 2, War 12-15 (I don't actually need to go that far), magic 4-5.

I rush light/heavy plate and superior cutting weapons, then I kill everyone with an invincible army of 4 dudes who aren't even that costly to produce.

I never go up the diplomacy tree...

I hit the adventure tree early, then the warfare track, then the bare minimum i need from civilization and magic, and then back to warfare all the way.

First round get 1 in each but adventure, need caravans. 

Then just go 2-3 times in civ war and magic, need shard arcane research. 

Then go into civ and war multiple times, econ, housing, and farming along with weapons and armor

By that time civ and war is about 11-15, definitely need archers, I'll go for adventure to get resources

Then back between civ, war, and magic.

I don't care about dynasty or treaties in diplomacy.  I do not care about higher champs and quests, etc. in adventure.  I usually have plenty of champs already and trying to equip them takes much money for good equipment, along with balancing with city improvements. 

I don't play Empire much (and I've only really just started playing the game at all; held up by my crazy work schedule in even years). I also tend to play on epic (slow research) with large maps.

I tend to lean heavy civ first with a sprinkling of adventure/magic/war/treaty. I view most 4x games as an infastructure/tech race and civ get me the infastructure and tech production increases I can then apply to other areas.

I want enough war to deter hostility; how much depends on who is close. I want spears and leather for the most part. Horses if the resource is available as mounts are the most cost effective way to get speed if you have horse resources (I mean you cant use them for anything else so those no real lost opportunity cost to using them and mounting soldiers only costs the horse and no training time). I usually have two versions of my troops a mounted and unmounted that I can build the mounted one while I've got horses and the unmounted if I need a soldier and don't have a horse. I also want to get to logistics fairly early if hostiles aren't there.

I also want trade and treaties in early diplomacy as those can slow down aggression and because I'm econ and tech focused I can get a fairly good return rate on treaties and the earlier I negotiate them the less they cost me (a couple gildars investment in getting these treaties pays huge dividend over the lifetime of the treaty). Also it's been my experience that I've been able to maintain diplomatic stances with other kingdom governments and I'm very thankful to have finally found a 4x game where like minded friends don't suddenly turn on me for what seems to be capricious reasons that are not in their self-interest. I do tend to slow down on treaties after these opening abilities as the next diplomatic mile stone doesn't matter until I have kids of the proper age and that's ages in the future.

Magic depends a lot on my stating position; if I've got temples and shards I'll do some early magic research so I can use that stuff and if I've got a consistent shard type I'll go as far as research down the lines of the spell books for that shard (current game is really early but it looks like it's going to be a magic heavy game as I've got temples and 3 fire shards near cities). I think magic seems to be one of those things that you've got to get lucky to make it worth the investment early and if I don't have much spell research power or mana generating power it's hard to really justify the tech research in magic.

Adventure techs need a bit of a rewrite in their descriptions of what they do (just realized I've not looked at these in 1.09r so maybe this has been done). I just want it to be a little easier to see at a glance whether quest level or location level is being raised. My speed at doing these depends a bit on what my neighbors do. If they spawn goodies I'll do the research about getting those goodies because the AI tends to spawn them but then doesn't have the ability to open many of what they've spawned. Since I usually sign an early NA treaty with everyone I just wander around their kingdom with my hoard of heroes popping their goodies. The resource spawning techs aren't really good enough for me to go after unless I'm really short on something (though the boost to the food spawning one makes it way more attractive than it used to be).

Civilization techs are the heart of my power, the ordering of the research priorities here depends on what resources I have though I'm invariably shooting for the housing improvements, tech generation improvements, and production improvements. The money improvements are tied to housing. Mining and farming priorities depend on need for food and availability of mines (my current game I've got huge numbers of farms/shards/crystal related stuff but haven't yet found a mine (perhaps I should go after the adventure tech for mines).

-Starcrunch

Turn 138, hard difficulty.

4/4/3/4/1

Seems balanced right now, but after this I will go almost entirely into civ and war (unless I really want dragons, or have a hankering after a quest win).

Civ- concentrate mainly on gildar, economic, and housing boosts. In most of my games my primary constraint seems to be gildar so I try to boost this as fast as possible.

Warfare- currently by far the most useful, but I actually never usually get beyond light plate and first tier of differentiated weapons, by then the game's pretty much over. I'm pretty much with Werewindlefr. I can generally rush with a few dudes in plate plus weapons with little resistance, just use these meat shields to protect 4-5 magic spamming champions and its all over.

Magic- almost useless in the current form, I normally grab all the books except tereforming on character creation. Almost never need to get the elemental spell books. The combat and mobility spell books are really the only ones you need. The boosts to arcane research are never important. All my research needs are taken care of by arcane labs. I've never needed anything else. Only tech I might go for later on is Shard mastery to get the mana boosts. Other than that nothing is really that useful currently.

Adventure- Important for resources and goody huts, thats about it. I'll pop some adventure techs if I really need the extra food of if I still haven't come across a source of metal.

Not even sure what the hero's line even does right now. Even without researching it I still see (and can recruit) high level heroes that are walking around. However, I have no real incentive to do so. Why bother paying 300 gildar for a high level hero that been customized poorly (points spent in Charisma? WTF) when I could spend that 300 gildar on armor and weapons for my ubber meat shield that I've customized since day one.

The quest line is essentially useless (unless going straight for quest victory, which is probably way to easy compared to domination) unless you have extra quest mods installed. There just are not enough interesting quests with good rewards in the vanilla version of the game to make these techs worthwhile.

Diplomacy- Grab trading for the gold boost, same with treaties. Other than that this tree is a wash. Unless I REALLY want to play with some dragons I never go any farther in this tree. As long as the opposition unlocks it I can marry off my children so nothing lost there. This is probably the least useful of all the trees.

A few ideas to make the other tech trees more useful/interesting

Diplo tree-

Make the creatures made available by this tree more interesting. Problem is that the creatures made available are generally not worth the price of admission. I'll research up to dragons just because they're cool, but if I want to win the game then I'm going to just go up the war tree. 

A couple problems/potential solutions-

1) When you unlock each one you can only build in one city, the one that pop's the associated resource. Which tech should I pick, one that lets me train powerful units in every city, or one that lets me train powerful units in one city? Not much of a choice. Solution- give us a building (say for level three cities) that lets us train these units in any city provided we have the resource somewhere in our empire.

2) The early allies are not very strong. Dragons are awesome. But the spiders, the shrill, and the drath are usually not as good as equivalent normal soldiers. Solution- make all the special allies much more powerful, and then nerf by only allowing a limited number per resource. For instance, perhaps the drath are 2 x a powerful as a normal soldier, but you can only have 10 of them per drath village you control. Well you can bet I train my 10, what an awesome shock force, but beyond that I'm limited.

3) All of the allies are not very interesting. They're just boring. I can train one type of spider, ho hum. I can train one type of shill, yawn. I can train one type of dragon, boring! Make all these allies more interesting and customizable. Make we WANT to play a game where I go down the diplo tree to the exclusion of the war tree.  Let me get ice dragons, fire dragons, death dragons, Gold dragons, etc. LET me ARMOR up my dragons with plate mail! Let give them magical items too. Make these bonuses unlock-able through further diplomacy tech. The dragons initially scoff at your suggestions that they wear you puny human made armor "our scales are all the protection we need" they reply. However, a gifted human smith spends a year with the dragon lord perfecting his craft and convinces her to allow him to craft armor for her children. 

4) Re-implement minor factions (I haven't seen any for many many games) and give the dipol tree bonus with them. And then make these bonuses really useful. For instance big discounts at their shops of unique and powerful items, free powerful units from them every few turns, etc. 

Magic Tree-

Right now magic is essentially three things: spell books, mana harvesting, magical equipment.

1)Magical equipment and crystals. Make these more interesting than just slightly improved versions of those available up the war tree. Take a page from your own book and make magical creatures that are construable in cities: golems, specters, etc. and make the same adjustments as stated for the diplo tree. Finally to make them all interesting put in a rock paper scissors mechanic between the creatures in the diplomacy tree, magical creatures and equipment, and normal human soldiers with catapults. Magical constructs and crystal blades are vulnerable to good old fashioned plate mail and massive rocks. The creatures of the wild however are vulnerable to the crystal enchantments within your golems. However, those dragons make mincemeat out of knights and catapults are generally useless if they're on fire from dragons breath. RPS may seem contrived and overused, but there is a reason its overused: it works as a good way to force different strategies.

2) Spell books (never quite understood why their in this tech tree and not something you have to devote arcane research to discovering) But anyway, they occur very early in the tree and only a couple are really useful. Based upon the lore of the game we should want to specialize in one or two (the one or two we have shards for). Make this possible, make them all useful and dramatically increase the benfits to having shards associated with them. MAKE THESE MORE POWERFUL THAN THE BOOKS YOU CAN START THE GAME WITH! Then incorporate higher level books further down the research tree in order to unlock even more power. Don't just let me research the fire book as my third tech and be done with Magic for the rest of the game.

3) Mana harvesting, probably the only reason I go down this tree currently, and I can pull in all the needed techs researching magic about 5 times. No need for anything beyond that. Two improvements, make mana more dear by making permanent enchanments (especially city buffs) more powerful, I'm sitting at turn 138 in a game and have 756 mana in reserve. Mana is not a pressing concern right now. Second improvement, make a longer string of mana enhancing improvements. Right now there are essentially two shard harvesting and shard mastery. Once you have these you're done. Give us a few more that also give boosts.

I use different sequences depending upon map size/distance to next nation and monster density

on large maps with low monsters and large distance to next nation I usually focus on civ, till founding second city, then grab trade, then if shards/crystal nodes in range magic up to arcane armour and shard harvesting and back to civ till only refined researches avail, then add military again till refined are the only choices,then top up magic to refined, then do diplomacy and last adventuring.

on smaller maps or high monsters or small distance to next nation i usually grab the food increase/house increase/production increase, then add trade & dips, then alternate between magic & military, then top up civ especially the prestige items with adventure last.

harpo