Star Wars Total War: Imperial Warlords
In this game, while different factions have different advantages and disadvantages shaping their faction. Doctrines sometimes play a bigger role in how they play. The doctrines are the foundation of how a factions armed forces fights, an influences the tools at your disposal. Each doctrine offers units and buildings to the faction, and some may have faction specific unites tied to certain doctrines. Choosing which doctrine to go for is really important, for they have their strenghts and weaknesses, on top of being built for situations that may not align with what you have at your disposal.
Old Republic Space Doctrine
The doctrine is inspired by the Clone wars. Built around the idea of essentially staking claim on a planet and basically telling everyone else to kriff off or die. And well, people tend to listen as they are REALLY GOOD at any sort of planetary invasion, regardless of being on the defense or offense they can usually back up the claim. They typically field versatile big ships, though they very much have a very notable edge in any planetary assault operations against other doctrines. Though their ships tend to be on the expensive side making them somewhat harder to maintain. But, if caught in deep space, their specialty can cause some real trouble.
Clone Ground Doctrine
This doctrine is built around the infantry. Well equipped, decently trained, and with a vast toolbox to call upon, they are a very versatile force that under a competent commander, can take most planets ESPECIALLY when backed by a Old Republic Space Doctrine fleet. The force is one of the most flexible, albeit lacking in less combat-intensive methods.
Rebel Space and Ground Doctrine
Both doctrines are poorly suited to holding ground in a conventional fashion, which is fitting considering the inspiration are insurrectionists. While not that capable in a direct fight, they are nasty when given an opportunity to do their thing, you will quickly find just how quickly things can go to blip as they wreck havoc in enemy territory, exploiting mobility, enemy unrest, and abilities to keep the enemy from being able to reliably respond.
Droid Space and Ground Doctrine
Rather unique, in that the infrastructure to produce is quite costly. But once built, they can produce units that while weak, are so cheap it hardly matters. They are pretty much the ultimate spammer doctrines, as they are one of the few that could probably respond to a total loss, by simply tossing another force in the general direction. While very inflexible and with limited options, there are very few faction-doctrine combos, other than fellow droid Doctrines that can out-attrition them.
New Republic Space and Ground Doctrine
In both the Ground and space, the Doctrines field a variety of specialized units that work best with full communications, and absolutely nightmarish in defense. These Doctrines are very heavy on the defenses, for if there isn't enough to deter even massive assaults, then clearly there needs to be more. On the attack, their forces tend to be lacking, but on the defense, any force, no matter the doctrine is going to be in for a hard time if they were able to dig in. The sheer level can even be enough to contest a old republic doctrine in their element!
Tarkin Doctrine
This doctrine is built around psychological warfare. Both Ground and Space is built around trying to destroy the enemy's morale, whenever it is oneshotting an enemy capital ship with a superlaser, through Big armor, or just well-placed bribes and-or emergency relief efforts, contrary to what one may assume from how Tarkin operated. They aren't built to end a fight by conventionally destroy a force, but rather by destroying the will to fight, going so far as to consider reputation as an important weapon. Although, Terror, for all of it's flaws is the easiest part to use. It tends to either works great, or not however.
Imperial Space Doctrine
Their answer to everything is usually more guns. Rather basic but it tends to work. Their ships are a bit expensive, but the sheer firepower and respectable durability means they can really hammer those it fights against. It is nice and simple, not really using much in the way of tricks and fancy tactics because bringing enough guns works pretty well.
Veers ground Doctrine
With heavy armor and a large force of infantry, they typically try hammer and anvil tactics on enemies, with armor being the hammer and infantry being the anvil. In general, they use their very numerous assets to try and smash their enemies while ideally limiting their casualties. Though their focus on size without costing quality makes them rather expensive, and they don't exactly have any advantage in replacing their losses. However, clever use of their armor can be devastating.
Chrhod doctrine
In both ground and space it is built on the idea of making a force the best it could be. Ending with a whole army of special forces, they can hit much harder than you may expect, which is good considering not being outnumbered against a peer while using this doctrine means something went horribly wrong for your opponent. While powerful, they take a long time to train, meaning losses will be felt for a long time, making attrition warfare very bad for this doctrine short of insanely lopsided K/D ratios.
A/N: Well, was inspired to try and write an omake about a hypothetical video game based on the quest. Though the tidbits on doctrine may not be that accurate.