Unit (Civ2)

A unit is a mobile actor in Civilization II. Each unit in the game belongs to a specific , denoted by the shield icon accompanying its sprite (and in Test of Time, sometimes the color of the sprite itself). Units can perform a variety of roles and including exploring the world, engaging in , and establishing new .
Units are by cities, and can incur varying costs (including stress) depending on the player's . When a city is conquered, all affiliated units are instantly disbanded. As a player's progresses, new units become available and obsolete types are removed or replaced as build options; the civ controlling the will automatically upgrade older units in the field.
A standard game features 51 unit types. The original Civ II includes three unused definitions available for ; expansion packs add another eight, for a total of 62 possible units. Test of Time adds a further 18, for a maximum of 80 definitions.
==Basic attributes==
Each discrete unit belongs to a general type, identified by its name and sprite. Most unit names are pluralized, representing formations and teams, rather than individuals. A unit can occupy a single at a time, with multiple units on the same tile forming a stack. Only units belonging to the same civilization can stack.
Unit types and their statistics are detailed in the "Units" section of the Civilopedia, including most (but not all) of certain units' special abilities. A player's active units are listed by the ; the "Casualties" page tallies all own units defeated in combat, and the losses of each civ with which the player has an . In the Multiplayer Gold Edition, an additional menu, "", logs each lost unit by date, including map coordinates, nearest city, and the defeating civ.
===Domain===
A unit's domain determines what it can access. move over land, over , and can traverse any tile, but will typically require refueling at an appropriate landing zone after a certain number of turns. Sea units can also enter cities regardless of underlying terrain; so-called canal cities can enable naval movement between otherwise-inaccessible water bodies.
====Transportation====
Ground and air units can be carried over ocean by suitable , such as s and s. Units can move into a transport from any tile, but will forfeit their remaining movement points. Units can be loaded onto transports in a city with the Sleep () order; this preserves their available movement if reactivated. Units unloading from a transport retain their full movement, even if debarking directly to shore.
Note that air units will automatically follow a carrier out of port, regardless of their given order or remaining movement.
===Role===
Units are categorized into two broad groups: , intended for conducting combat, and , which perform special functions such as , , and . A unit's role determines how it is used by the , and may grant certain special conditions and actions. There are eight defined unit roles:
* : Geared for attack and maneuver warfare.
* : Geared for land defense and city garrison, secondarily offense with suitable attack strength.
* : General-purpose warship equally suited to attack and defense.
* : Aircraft geared for air defense and interception.
* : Intended to ferry units over ocean, secondarily naval superiority with suitable attack strength.
* : Able to found new cities and construct s.
* : Able to conduct .
* : Able to establish s.
===Movement===
A unit's movement rate (also known as movement points, or MP) is the total number of tiles it can traverse during the turn. Certain terrain has a higher movement cost, while ground units following s, s, and/or s expend a fraction of total movement; air and sea units move at a flat rate of 1 point per tile, regardless of given cost. Unlike in the original Civilization, units will always move into "high cost" terrain if they have not exerted themselves since the turn's start; otherwise, there is a chance they will be blocked and forfeit the rest of their turn.
Generally, units may continue to act for as long as they have movement points remaining, unless performing an action. Air units moving into a tile containing a suitable landing site (city, airbase, or carrier) immediately end their turn, regardless of remaining movement. Military units attempting to enter a tile containing a foreign unit or city when not at will prompt an advisory message (if allied) or confirmation to initiate combat; if the attack is aborted, the unit loses 1 MP, unless a ground unit is accessing an ally's city.
Units that have sustained damage will have reduced movement proportional to their remaining hitpoints, to a minimum of 1 (ground) or 2 (sea); air units always retain maximum movement even when damaged.
====Zone of control====
All ground units exert a zone of control on adjacent tiles that restricts the mobility of foreign units: most ground units whose owners are not cannot move adjacently, or between zones of control within or among rival civs.
Certain units, including all trade and espionage units, are not subject to zone of control.
===Vision===
Civilization II employs fog of war, but does not delineate active vision within the explored map. Units can normally see everything in adjacent tiles, except for stealth units such as s.
Certain units feature an extended line of sight up to two tiles, dependent on the unit's domain: ground units cannot see into ocean and sea units cannot see into land, while air units have unimpeded line of sight. Note that extended vision does not combine with anti-submarine abilities: such units will only reveal cloaked units immediately adjacent to them.
===Prerequisites and obsolescence===
Most units require specific s before they can be built. Older units can also be rendered obsolete, remaining in the field but removed as a city build option. If the retiring advance enables a suitable replacement, production is automatically upgraded; the automatically upgrades obsolete units in the field to their nearest evolution each time a new advance is acquired.
 have special conditions: they can only be constructed (by any and all civs) once the is completed, and require knowledge of in addition to their stated advance.
===Cost and support===
Units are constructed in cities for a per-type cost. If the unit is manually disbanded in a city, half its Shield value is immediately added to the city's current production progress.
A unit is automatically linked to its originating city, identified in the "Status" window of the . The also lists affiliated units in the "Support" window, and identifies the home of garrisoned units by the first three letters of their city's name. Units awarded from s or may or may not be assigned a home city, depending on their proximity to rival civs' settlements vs the player's own. If the home city is lost or captured, all affiliated units are instantly disbanded.
Home cities pay persistent for their units, in the form of diverted production output at a rate of 1 per unit. If a production deficit occurs, units will be disbanded at the start of the turn, prioritizing those stationed outside the home city. "Military" s provide a variable level of free support per city. Additionally, incur a support cost that varies by government type. Units with 0 Defense strength, and all Trade and Espionage units, do not require support.
A unit's home city can be reassigned through the "Set Home City" order () when stationed in the desired city.
====Happiness====
Under and , military units "in the field" (not stationed in a city or a within three tiles of the player's city) provoke : under Republic, each unit after the first causes one , while under Democracy, every unit causes two . Additionally, all air units other than provoke war weariness regardless of where they are stationed. War weariness can be mitigated per-city with s, and empire-wide by the Wonder.
Conversely, under military governments, military units garrisoned in a city impose , converting 1 citizen to per unit, up to 3; under , this effect is doubled (-2 per unit).
==Controlling units==
Units are primarily controlled through the . The currently active unit appears as a blinking sprite (or a blinking tile marker in Test of Time), with the Status window detailing remaining movement, home city, and underlying terrain, as well as listing other units present on the tile. Units are moved via the keyboard using the number pad, directional arrows by hovering the mouse cursor over the sprite's edge, and/or by click-dragging to the desired destination. The game automatically cycles between active units each turn; the player can activate specific units by clicking them on the map or the city screen, or while the active unit/map cursor is on a stack, selecting "Activate Unit" () from the .
 Unit movement keyboard map
7 NW 	8N	9 NE 
4W 	 	6E
1SW 	2S	3SE
The following is a list of common unit orders; note that certain roles and domains alter available actions. Trade and espionage missions are not discrete orders, but are conducted by moving the unit into the target's tile.
* Pillage (+): Military unit destroys an improvement on the current tile. 
* Unload (): Activates all units onboard a transport.
* Go To (): Orders a unit to automatically move toward the target city.
* Airlift (): Available with ; transfers the unit between two cities with s.
* Go Home to Nearest City (): Orders a unit to automatically move toward the nearest controlled city.
* Set Home City (): Available to garrisoned units; assigns the current city as the unit's home.
* (): Entrenches for 50% Defense beginning on the unit's next turn. Unit will remain in place until manually activated, removing fortification.
* Sleep (Sentry/Load; ): Deactivates the unit, greying out its icon; automatically reactivated if a foreign non-allied unit moves adjacent, or a damaged unit has recovered its full health. Sleeping units in a city automatically follow a transport; this is the default state for ferried ground units (but not air units).
* Disband (+): Immediately removes the unit from the game, nullifying any support costs. When performed in a city, half the unit's value is added to the current production order.
* Activate Unit (): Activates/clears orders of the unit on the highlighted tile. On a stack, opens a menu listing all units present.
* Wait (): Defers action until later in the turn.
* Skip Turn (): Immediately ends the unit's turn, forfeiting any further actions.
==Combat==
 in Civ II occurs when a military unit attempts to enter a tile containing a hostile foreign unit. Each unit features a set of statistical attributes that determine its performance in the ensuing battle:
;Attack: The base strength of the unit when initiating combat.
;Defense: The base strength of the unit when attacked.
;Hitpoints: The unit's quantified maximum health, times 10. Each combat round inflicts damage to hitpoints equal to the winning unit's firepower. Once a unit's hitpoints are depleted, it is destroyed. The health bar above the unit's shield icon provides an at-a-glance gauge of its remaining hitpoints: a green bar indicates 0%–32% damage, yellow 33%–65%, and red 66%–100%.
;Firepower: The number of opponent's hitpoints damaged when the unit succeeds in a combat round.
Attack and Defense determine the relative probability of the respective unit winning each combat round and inflicting damage against its opponent. Combat odds are further modified by certain roles and abilities, and multiple defensive factors including terrain type, cy, fortification, and such as es and . Combat continues until one unit's hitpoints are depleted, removing it from the game; if a defeated unit is defending on behalf of a stack that is not stationed in a city, fortress, or , the entire stack is destroyed.
If playing with , hitpoints and firepower are ignored, and combat occurs in a single, "all or nothing" round as in the original Civilization.
Ground units can only engage land-based targets; units other than cannot attack directly from sea transports, but must first return to a land tile. Sea units can attack coastal land tiles, but have their Firepower reduced to 1. Air units can attack ground and sea targets; airborne units that are not s can only be attacked by appropriately designated units such as s.
===Veterancy===
cy is a status that provides a 50% bonus to a unit's Attack and Defense strength. A unit that survives combat has a 1-in-2 chance of gaining veterancy, which persists for the rest of its life unless upgraded to a newer type by Leonardo's Workshop. Certain s provide veterancy to all units produced in the city based on domain: (for land), s (for air), and (for sea). and the also provide veterancy to all new land and sea units, respectively; the Academy also grants veterancy to any unit that survives combat.
===Repairing damage===
Units can recover 10% of their total hitpoints by skipping a full turn (performing no movement or action, except Sleep, Fortify, and travelling along s); units in fortresses and cities recover 20% of their health. Additionally, ground units within three tiles of an owned city recover an extra 10% health, and 20% if it hosts a barracks. Units skipping their turn while stationed in a city with an appropriate veterancy improvement (Barracks, Airport, Port Facility) will recover their full health, as will air units at airbases.
Ground units attempting to enter an city immediately end their turn, instantly recovering 10% of their health (20% with barracks), in addition to a full round of repair at turn's end, even if the unit has moved. Sea and air units do not receive a repair bonus, and ships will forfeit a movement point as per normal aggression rules.
==Demographics==
A civilization's military service is calculated from the ratio of military units to citizen count, based on the following formula:
:
where is the total number of fielded military units, and is the total citizen count. A longer military service provides a higher demographic ranking.
==Modding==
Units can be added, removed, and edited during a game via commands. Fantastic Worlds and the Multiplayer Gold Edition include a that can modify unit types and associated mechanics within the active session.
Units are defined under the section of . Certain abilities are hard-coded to specific slots; consult for details. The total number of recognized entries varies by game version: the original Civilization II features 54 types; Conflicts in Civilization, Fantastic Worlds, and the Multiplayer Gold Edition feature 62; and Test of Time features 80. 
Unit graphics are defined in , organized in horizontal rows corresponding to the Rules definitions. Original versions of Civ II through to MGE use an indexed 256-color palette, while Test of Time enables 24-bit "true color" and features a taller sprite ceiling, in addition to support for .
Unit employ a combination of domain-specific defaults, shared suites (such as the effects), and unique effects tied to specific slots and flags. Test of Time adds a section to Rules.txt that allows specifying a custom sound for any unit.
==Footnotes==
==References==
==See also==
* Unit in other games
Category:Game concepts (Civ2)