It's been posted several times by the developers that they're trying to make each tech tree a viable choice, with Civilization using influence, Magic using crystal, and Warfare using metal. But from my experience and from what I've read of others, everyone starts out focusing on the Civilization tree because you need a base level of gold, research, and production in order to make a viable kingdom or empire. Nearly all of those very important things are in the Civilization tree right now - what if alternate methods were spread out in the other trees, making each tree a completely self sufficient research path? Some initial ideas are below - I'm deliberately sloppy in defining something as a tech or a building, in an instantiation they might be either or both.
Civilization
Civilization would be the "defensive" tech tree - kingdoms and empires focused on internal growth would research its technologies. Some techs would grant extra defenders to cities and even outposts. It's currently the most independent tech tree
Magic
The basic idea here is to allow magical techs that provide food, production, research, and population growth from mana and/or crystal, as well as improving mana and crystal production and city defense. These could be independent techs, or somehow be worked in to the existing tree
Food Techs
Enchanted Gardens: Building that provides additional food from grain, sells enchanted fruit / veggies in the store that gives bonuses
Cornucopia: City enchantment (stackable up to a certain value) that provides N food, but has a mana maintenance
Birth of Summer: Same effect, or, if cast on a city, increases the grain yield of that city by 1
Production Techs
Enchanted Construction: Increases production per material, can rush buildings with mana
Animation: Grants a spell to summon a golem; golem workshop building increases production per material, grants a golem as a city defender
Greater Animation: Spell to summon an obsidian golem, artisans workshop building increases production per material, also grants a golem as a city defender
Research Techs
Same theme - city enchantments and magical buildings that increase research at the cost of crystal and mana
Brilliance: Like an improved version of Inspiration
Sorcerer's Enclave: Building that increases research by N, also by M%. Provides a low level fire mage for city defense
Population Growth
Guiding Beacon: City enchantment that magically provides wanderers direction to your city, increasing population growth by N
Also needed would be some techs to increase crystal production and mana generation.
Warfare
The warfare would be extremely attack focused - a kingdom or empire using warfare but not at actively at war would be at a serious disadvantage. Warfare would focus on using slaves and foragers to increase food, population, and production, and would gain research by being victorious in battles. I could see Warfare taking over the slave related empire trait.
Foraging:
Food could be gained by foraging armies - every army in enemy territory would add N food to each non-conquered city. An advancement of this tech would allow (reduced) foraging from armies in neutral territory.
Production:
Blacksmiths, armorers, weaponsmiths would all add production and possibly materials
Slave Labor
Technologies and buildings that improve food and production per population. A Plantation might give 0.25 food per population (slave labor), or labor pits might give production per population. Slaves (population) would be gained from conquering (not razing) cities. Or maybe each conquered city gives a food and production "tribute" to all founded cities.
Research
Using the idea in the recent patch notes about trading tech "points", being victorious in battles would add these tech points in addition to experience.
Any other ideas on how to make warfare completely independent of the other trees? How can a kingdom or empire completely free itself of the other tech trees and just make conquering everyone its business? Has anyone tried researching just one tech tree (not civilization)?
Poko