Units, Combat and Expansion

## Overview

Units are unlocked as you progress through the technologies. Some require specific Buildings to be able to produce them, whilst Social Policies, Buildings and Wonders can have a variety of effects on the units.

## Unit Classes

Units fight in a specific order according to their class:

* Siege Attackers
* Ranged Attackers
* Ranged Defenders
* Melee Attackers
* Melee Defenders

Siege units owned by the defender do not fight and are treated as non-combatants.

Units and Class - note that Nation-specific units are listed alongside the standard unit:

* Siege Units:
	+ Catapult/Siege Tower
	+ Trebuchet
	+ Cannon
	+ Artillery

* Ranged Units:
	+ Archer
	+ Longbowman
	+ Musketman/Minuteman
	+ Rifleman

* Melee Units:
	+ Offensive Infantry
		- Warrior/Eagle Warrior
		- Swordsman/Legion
		- Longswordsman/Samurai/Berserker
	+ Defensive Infantry
		- Lancier/Hoplite/Immortal
		- Pikeman/Impi
	+ Mounted Units
		- Horseman/War Elephant\*
		- Knight/Keshik\*
		- Cavalry/Cossack/Conquadistor\*

Units marked with an \* are treated as Ranged units when fighting in combat.

## Combat Mechanics

Experiments indicate that Att seems to be damage done with Def behaving like Hit Points. The Att score for each group of combatants is pooled then dealt out to the enemy forces. Once a unit has taken an number of hits equal to their Def then the unit is destroyed, possibly denying the chance to fight back.

As such, Ranged Units are considered to be stronger than Melee Units. Siege Units, although stronger on attack, suffer from being useless in defense and usually slower than Infantry units resulting in them being considered highly specialized.

* Siege units have the bonus ability of being able to destroy enemy defense buildings in addition to fighting first

Note that the application of Attack against Defense isn't a simple addition and subtraction. If you have 30 archers, sending them in one attack wave will kill fewer defenders than if you split them into two attacks, i.e. 25 and 5. This is a source of frustration for many new players, when their quite large armies fail to capture a city (see below), leaving just one or two survivors. This is even more annoying when you are trying to occupy a barbarian village, only to weaken it for the AI competitor.

## Expansion

Expansion can only occur through conquest. Both you and the AI will compete to capture Barbarian Villages and, in times of War, each other's cities.

To conquer a village you need:

* An Army (25-50 Archers will handle many Barbarians early on)
* A Governor
* Complete annihilation of all defending troops.
	+ There is the option to destroy (burn) a city rather than capture it - this is useful if:
		- The city is being used to launch attacks but the happiness penalty would be unacceptable to allow capture
		- The AI has constructed a Wonder (burning a city containing a Wonder allows it to be built from scratch).
	+ There is the option to keep troops in a captured city. This decision should be considered carefully as often there will be insufficient gold to fully support the army resulting in units being disbanded.

## Other Information

* As of 1.3.6, the AI seems to cheat - barbarian villages at all times know the size of the defenders in all your cities and will generally attack all undefended or poorly defended cities, sometimes just a few seconds after all your units have been dispatched to attack somewhere. This could be also used to your advantage - as defenders always get a bonus, you can deal with quite big barbarian armies by luring them to attack one village and attack their home while they are away.

* Also, barbarians do not seem to send Governors in their attacks, so in early game you can easily avoid major losses by sending your defenders on a counter-attack and simply spending all your gold (you can even queue it it units/buildings and once the attack is over, cancel the purchase to get the gold back).