Civilization Revolution/Units

Units in Civilization Revolution represent a mobile troop of soldiers, most of which are capable of combat in some form. Units are essential to expanding an empire, defending existing cities, and conquering opposing armies and cities. They are typically built at cities, although they may also be gained through the discovery of friendly villages, Mysterious Artifacts or several other uncommon methods.

Statistics
Each unit has four basic statistics. These determine the effectiveness of the unit and are comparable across all units:


 * Attack: Determines the Combat value of the unit when it is performing an attack.
 * Defense: Determines the Combat value of the unit when it is defending its square.
 * Movement: The number of non-road and pathable regions that the unit may travel every turn. A unit requires at least one remaining point of Movement to perform an attack.
 * Cost: The amount of Production required to produce a single one of these units.

An indirect statistic of each unit is the Health or Number of troops. This directly relates to the number of troops observed in the staged combat. When at maximum health (number of troops), the unit will fight as normal and at full strength. During combat a unit may lose health (lose one or more troops) and as a result, will fight at a fraction of its nominal strength. This fraction is equal to the fraction of units remaining, e.g. a Warrior unit with 2 out of 3 troops will fight at 2/3 strength. If all troops should fall, then the unit is destroyed.

One troop per turn may be restored by "resting" the unit in friendly territory for a turn. Note that the unit must be told to Wait and not Defend in order for it to regain Health. There are advantages and disadvantages to having a higher troop count to a lower troop count, but the number of troops is generally lower for higher quality units.

Unit control and armies
Each unit may be told to perform one of the following actions, not all of which are always available.


 * Move: A unit may move across one pathable region for every point of Movement it possesses. The definition of "pathable" is naturally different for land units, air units and naval units:
 * Land Units: Land units may travel over any terrain except for Mountain, Shallow Sea, and Deep Sea regions. Land units do not use up Movement points traveling along Roads (although at least one point of Movement is still required to issue the move command). Note that moving between a pair of connected Cities will always cost exactly one Movement point.
 * Air Units: Air units may travel over any terrain.
 * Naval Units: All naval units may traverse Shallow (coastal) Sea regions, and all naval units except the Galley may traverse Deep Sea regions. Naval units may not travel over any other type of terrain.


 * Attack: A unit may attack any unit that it may reach through movement. The unit will have its Attack value plus bonuses pitted against the strongest defender in the target square. For more detail see Combat below.


 * Wait: Ordering a unit to wait will remove all of its Movement points for the turn. If the unit is damaged and is located in home territory (or anywhere with the "Medic" Special Ability) then it will be healed by one troop.


 * Defend: Ordering a unit to defend will entrench it at its current location. This grants a Fortification bonus of +50% Defense, and if left Defending will become Heavily Fortified with a +100% Defense bonus. Ordering the unit to move will reset its fortification bonuses. While defending, the unit is also removed from the cycling list of active units.


 * Special Function: Several units have a Special Function, which may be invoked at a relevant time. This includes the Settler's ability to populate or create a City, the Caravan's ability to automatically map out a trade route, or a Great Person's ability to settle in the current City.


 * Create Army: If three of the same unit are located on the same region, then they have the ability to merge together into an Army. Armies behave as a single unit, but their attack and defense values are triple that of the base unit, e.g. one Catapult is 4/1 (Attack/Defense), while a Catapult Army is 12/3. Movement is not affected, and any Special Abilities of the child units are carried over to the new Army. Armies themselves cannot be formed into even larger armies. When forming an army, a suffix is appended to the unit's name to identify it as an army. The attached suffix is chosen to suit the base unit, e.g. Riflemen Army, Cruiser Fleet, Fighter Wing or Spy Ring.

Combat
Combat is initiated when one combat unit attempts to occupy an adjacent region containing at least one unit of an opposing force. When this occurs, the following (automated) process is conducted:


 * 1) Selection of defender: If there exists more than one potential defender, the unit offering the strongest defensive combat value is chosen. If there is a tie between two or more defenders, then the unit with the weakest offensive combat value is chosen (by design, so as to preserve the attackers). Non-combat units and Great Persons will not defend. If the defending stack contains only non-combat units and Great Persons, then they are automatically destroyed or captured.
 * 2) Determine base combat values: The base combat values here are the base attack of the attacking unit, and base defense of the defending unit. This value may be lower if one of the participants is a damaged multi-troop unit. The value may also be higher due to Civilization Era Bonuses, a Wonder.
 * 3) Calculate and apply bonuses: There are many sources of combat bonuses. Percentage bonuses are all added together before being applied to the combatants' base attack values. Absolute bonuses are added after percentage bonuses. Note that combat is considered to take place in the defending unit's region, and hence region-specific or territory-specific bonuses are taken from the defending unit's region. If the attacking unit is located on a Hill however, they still gain the +50% combat bonus.
 * 4) Combat: The combatants exchange blows in a scripted fight, typically representing how close or how one-sided the battle is, as well as highlighting potential losses sustained by either side. There is a limited window of time within which the attacking player may choose to withdraw his/her units in a Retreat. Doing so will prematurely end the battle, giving the Defender an automatic Level / upgrade, but preserving the lives of the attacking unit.
 * 5) Victory and post-combat: The victorious unit receives a Victory and may become damaged. Defeating stronger armies increases the chance of the victorious unit sustaining damage. If and only if: the attacking unit wins, the attacking unit is a melee unit, and there exists no more defenders in the target square, then the attacking unit will move into the attacked region. In all other circumstances the combatants will remain in the original positions.

Experience & Special Abilities
Each unit may gain Levels by being victorious in combat. One level is gained whenever the unit either:
 * 1) Wins (another) 3 battles, or
 * 2) Defeats an opponent of equal or greater strength


 * If the unit has no veterancy, then it will be upgraded to a Veteran and receive a +50% Combat Bonus.
 * If the unit is already a Veteran, then it will be upgraded to Elite and gain one Special Ability.
 * If the unit is already an Elite, then the unit will gain an additional ability.

Elite units also have the chance of attracting The Great General, an automated unit that travels with the Elite unit and bestows a +50% combat bonus to the Elite unit and all friendly units in the same region.

When receiving a Special Ability, the unit will have a choice of two Special Abilities chosen at random from the pool of abilities not already possessed by the unit. Every ability will add an icon to the unit. The first ability gained by a unit will bestow upon the unit an additional title in its name. The following is a list of the available Special Abilities:

List of units
The following is a list of all standard units available in the game. Certain civilizations may replace one of these standard units with its own Special Unit, but the statistics remain unchanged unless the civilization also has a bonus to that specific unit. To aid in the conciseness of the table, properties and abilities of the units have been abbreviated into classifications. The explanations of these classifications are located below the table.


 * Melee: Will move into target square after successful combat. Attack -50% when attacking across rivers.
 * Ranged: Will not move into target square after successful combat. Attack -50% when attack across rivers.
 * Siege: Will not move into target square after successful combat. No attack penalty across rivers.
 * Aircraft: Must return to a friendly city once every 2 (fighter) or 4 (bomber) turns to refuel, otherwise the unit is destroyed.


 * Coastal: This naval unit may only move in Shallow Sea regions.
 * Support: Friendly land units fighting in adjacent squares will receive Naval Support.
 * Transport: This unit may transport friendly land units.
 * Scouts: This unit is constructed with an additional Militia unit onboard. This Militia unit possesses the 'Scout' Special Ability.


 * Non-combat: This unit may not be used to attack other units or cities.
 * Settling: May be used to create a new City or add population to an existing city. This unit may only be built if the producing city has a population of 3 or greater. The unit will be destroyed after using this ability.
 * Trading: May reach cities of other civilizations to produce Gold for both civilizations (the recipient City will only receive 1/3 of the Gold). The unit will be destroyed after using this ability.
 * Spying: May reach cities of other civilizations to conduct a Spying operation or attack a defending spy. May be garrisoned in a friendly city to defend against enemy Spies. This unit may not attack other units. Should a spying operation be conducted, the unit will be destroyed after using this ability.
 * Passage: This unit may move into other civilizations' territories, even during Peace.