Info: Attacking

Level:
Expert

Attacking
This info page describes 5 different commands: "attack", "assault", "paradrop", "board" and "lboard". These are the five commands that you use to take something (either a ship, land unit or a sector) from the enemy by force.

Note that much of the board information relates to the lboard information, just apply it to a land unit instead of a ship.

A combat has 15 steps:
 * 1)  Ask the aggressor for the target sector/ship.
 * 2)  Ask the aggressor further details about the offensive force.
 * 3)  Compute initial strengths.
 * 4)  Move reacting defensive units to the target sector.
 * 5)  Calculate defensive support.
 * 6)  Fight.
 * 7)  Spread the plague.
 * 8)  Take mobility and supply from land units.
 * 9)  Send reacting units home.
 * 10)  If successful, the aggressor takes the target sector/ship.
 * 11)  Remove mobility and efficiency from the target sector/ship.
 * 12)  Remove mobility from the aggressor's sectors/ship.
 * 13)  Possibly ask the aggressor for mil and units to move into the target.
 * 14)  Possibly interdict the aggressor's mil and units as they move.
 * 15)  Charge the aggressor BTU's.

Ask the aggressor for the target sector/ship.
There are some limitations to which kinds of sector can be targeted: The "assault" command is the only command which will let you attack your own sector (you can use this to get mil & assault units on shore). You should not "attack" unowned land (see Info: explore).
 * Sea, sanctuary, and wasteland are illegal targets.
 * You may not assault a mountain.
 * You may not paradrop into a mountain, capital, city, or fortress.
 * You may only board a ship from the sector the ship is in, you may not board a ship which is faster than your ship, and you may not board a submarine at sea.
 * You may only board a land unit from the sector the land unit is in.

Ask the aggressor further details about the offensive force.
When you board, you are asked for a ship or sector to board from. If you are attacking or assaulting, then you have the option to specify whether you want your forts/ships/plane/units to support your attack. If no support is specified, then it is assumed that you want support from all sources.

If you are not paradropping, then you will be asked for mil and units you would like to attack with. You must always leave at least 1 mil in the sector or ship you are attacking from, so you may never attack with all of your mil out of a sector or ship. The following limitations apply to the aggressor's mil: The following restrictions apply to the aggressor's land units: When asked whether you'd like to include a certain land unit in the combat, you will be given a prompt ending in [ynYNq?]. At this prompt, you can type:
 * Attack: You are limited by the mobility of the attacking sector according to the mob-cost to move the mil into the target sector.
 * Assault: If the target sector contains mil, then you may only attack with 1/10th of your mil on board, unless your ship has "semi-land" capability in which case it is 1/4th, -or- if your ship has "land" capability in which case there is no limitation.
 * Board: When boarding from a sector, the sector must have mob. When boarding from either a ship or a sector, the number of mil you may board with is limited to the maximum number of mil that the target ship can hold. Note that you can board land units from a sector only.
 * A land unit must have mobility and be in supply (see Info: supply) in order to be able to enter the combat. Land units with "supply" capability may not attack. Only land units with "assault" capability may assault or board.
 * Attack: The land unit will be charged as much mobility as it would spend marching into the sector. If that is at least as much as for a path cost of 1.0 (typically mountains only), it must have that much mobility, else positive mobility is
 * sufficient.
 * Board: You may only board with as many land units as the target ship can hold. You cannot board a land unit with other land units.
 * y - yes this unit
 * n - no this unit
 * Y - yes all units in this army
 * N - no all units in this army
 * q - quit attack
 * ? - print this help message

Compute initial strengths.
The offense strength of your land units is mil * off where "mil" is the number of mil in the unit, and "off" is the offense multiplier of the unit (see show land stats), with the following exceptions:
 * Assault: If the unit doesn't have "marine" capability, then its offense strength is cut in half.
 * Board: If the unit doesn't have "marine" capability, then its offense strength is equal to half of the number of mil in the unit.

The total offense strength is the number of mil plus the offense strength of all offensive units. This number is then multiplied by the offense value of the sector the mil and units are attacking from (see show sector stats). Ships have an offense value of 1.

The defense strength of a land unit is the total number of mil in the unit times its defense multiplier (see show land stats). The only exception to this is non-marine land units on ships which have a strength equal to the total number of mil in them. The defense strength of units out of supply is cut in half. The defense strength of fortified units is multiplied by (127 +fortification) / 127.

The total defense strength is the number of mil plus the defense strength of all defensive units. This number is then multiplied by the defense value of the sector the mil and units are in (see show sector stats). Ships have a defense value of 1 + def/100 (see show ship stats). You can use the "strength" command to see the defense strength of your sectors.

Move reacting defensive units to the target sector.
If the target is not a mountain, then nearby land units on reserve missions may react. Reserve units will keep reacting until the defense strength is 1.2 times the offense strength. The following restrictions apply to reacting land units: If the unit is in a 60% efficient headquarters, then 1 is added to its reaction range.
 * The target must be in the mission's op-area, and in reaction range.
 * The efficiency of the unit must be higher than it's retreat percentage.
 * The unit must be in supply.
 * The unit must have enough mobility to get to the target.

Calculate support.
For attack and assault, both offensive and defensive support is calculated. For paradrop, only defensive support is calculated, and for board and lboard there is no support (however, defending ships within range will fire on the boarding ship or sector before the fight if boarding a ship).

The aggressor's support is calculated based on what the aggressor asked for. Defensive support is only called in to the extent that it would be useful. If the aggressor outnumbers the defender 10-to-1, then the defender will not have any support. Otherwise, the defender will keep calling in support until its strength is at least 1.2 times the offense strength.

Fort, ship, and unit support is simply those forts, ships, and units in range that can fire (see Info: fire). Plane support comes from those planes on "support" mission. The support multiplier is 1.0 + fortdamage/100 + shipdamage/100 + planedamage/100 + unitdamage/100. Ships/forts/units belonging to allies of the combatants will support, if they are at war with the other combatant. (For example, if A is allied with B, and at war with C, and A attacks C, things belonging to B will support the attack if able. The same is true for defense. If C attacks A, the B stuff will help defend A.)

After these four supports are calculated, then land mine support is added to the defense support. Defending land mines add (number of mines) * 0.02 to a maximum of 0.40. If there are attacking engineers present, this number is cut in half.

Fight.
Total offense and defense strength are multiplied by their support multipliers to obtain the final combat strengths. From this, odds are calculated. Then in each "round", a chance according to the combat odds determines whether an aggressor or defender troop is lost. Troops killed in combat are first taken from the mil (from the sector containing the most mil), and then from the units (from the unit containing the most mil). Combat odds are recalculated and the process continues until there is a victor. Each time there is a casualty, a character is printed: If the effiency of a land unit is less than its retreat percentage when it gets hit, then it will need to make a morale check. The chance of failing a morale check is (retreat percentage - efficiency). If the unit has nowhere to retreat to, then it takes "extra losses" which amounts to an extra 10% docked from its efficiency. Otherwise, the land unit retreats to the adjacent sector containing the maximum number of civs. Units will never retreat into mountains.
 * ! means a defending soldier bit it
 * @ means one of your soldiers went down

Also note that once all of the military on a land unit are killed, the land unit stops defending. What this means is that a land unit can become "trapped" in an sector if an enemy takes it over after killing all the military on a land unit while the land unit may not be destroyed.

When planning an attack remember that overwhelming forces greatly increases your odds; i.e., attacking 10 men with 40 will result in your losing fewer troops than if you had attacked with 20.

Spread the plague.
If any combatant in a battle is infected with the plague, all potential comnbatants in the battle are infected as well (if they do not already have some level of plague already.)

Take mobility and supply from land units.
The "aggresor loss factor" is equal to the number of aggressor casualties divided by the total number of aggressor troops that went into the conflict.

Similarly, the "defender loss factor" is calculated. Then each land unit loses mobility equal to 10 * (loss factor). Also there is a chance equal to the loss factor that the land unit will use up some of its supply (see Info: supply).

Send reacting units home.
If the defending land unit did not retreat, then send it back to where it came from at no mobility charge.

If successful, the aggressor takes the target sector/ship.
Either 1 aggressor mil (first choice) or one land unit (second choice) is automatically moved into the conquered ship or sector to occupy it. Since this mil or unit is effectively "chasing out" the remnants of the defending forces, the defender will not interdict it (because he won't want to damage his forces with "friendly fire").

This is what happens to the sector when you take it: When you take a ship: When you take a land unit: When you take someone's capital, the defender loses half of their money or $3000 whichever is greater. If the defender wasn't broke to begin with, then the aggressor gets half of their money times (1/5 + 4/5 * efficiency of the sector).
 * 1)  All delivery and distribution information is wiped.
 * 2)  The production in the sector is stopped (see Info: stop).
 * 3)  Planes in the sector owned by the player you just took the sector from lose 30 plus random(100) efficiency and go to 0 mob. If the new efficiency is less than 10%, the plane is blown up.
 * 4)  Units in the sector owned by the player you just took the sector from lose 30 plus random(100) efficiency and go to 0 mob. If the new efficiency is less than 10%, the unit is blown up.
 * 5)  The avail is set to 0.
 * 6)  New che are created (see Info: Guerrilla).
 * 7)  Set the loyalty of the sector to 50 (see Info: Citizens).
 * 8)  Reduce the mobility to 0.
 * 9)  The civs in the sector become "conquered populace" (see Info: Occupation).
 * Mission, retreat info and fleet info is wiped.
 * Planes and land units on the ship are reduced to 10%.
 * Mission, retreat info and army info is wiped.
 * Planes and land units on the unit are reduced to 10%.

Remove mobility and efficiency from the target sector/ship.
The efficiency of the target sector or ship is damaged by a percentage equal to the total number of casualties divided by ten.

If the target is a sector, then it will lose a percentage of the mobility equal to the number of defender mil casualties divided by the total number of mil that were originally in that sector, up to a maximum of 20 mobility. So if for example, your casualty fraction was 70/100, and your sector started with 50 mobility, then you would lose min(20, 50*70/100) = min(20, 35) = 20 mobility.

Remove mobility from the aggressor's sectors and ships.
The pre-combat mobility costs are: Only sectors are charged an additional post-combat mobility cost. In this case, the amount of mobility the sector loses is calculated using the same formula as is used for the defending sector's mobility cost.
 * Attack: Remove mobility equal to the mob cost to move the mil into the target sector.
 * Board: If boarding from a ship, the cost is the half of the speed of the defending ship times the efficiency of the defending ship.
 * If boarding from a sector, the cost is the number of boarding mil divided by 5. This applies for boarding of ships and land units.

Possibly ask the aggressor for mil and units to move into the target.
If the combat was an assault, paradrop, board or lboard, then all victorious mil and units are automatically moved into the target. The mil are moved in with no mobility charge. If the combat is assault, then the mil will take an amount of food with them proportional to the number of people leaving the ship.

Assaulting units pay one update's worth of mobility, except for "marine" units, which pay only half of that. Unless assaulting from a ship with "land" capability, mobility is further decreased to one update's worth of mobility negated (so that the unit will have zero mobility after the update), except for "marine" units, whose mobility is decreased to zero instead.

For boarding, "marine" units are charged 10 mobility and other land units are charged 40.

In the case of attack, the aggressor is asked what they'd like to move in as follows: First, the aggressor is asked how many mil they would like to move in from each attacking sector. This number is limited by the amount of mobitity left in the attacking sector. Then the aggressor is asked which land units they'd like to move into the sector with the same [ynYNq?] prompt as above, the only difference being that 'q' now means "don't move anything in".

The mobility costs here are the same as for "move" and "march".

Possibly interdict the aggressor's mil and units as they move.
Post-attack interdiction only occurrs in the "attack" command (and not in "assault", "paradrop", "board" or "lboard"). When you move your mil into the target sector after an attack, you will risk the same chances of interdiction (number of mil / 200) and stepping on land mines (see Info: lmine) as if you were moving them using the "move" command.

Similarly, once you have specified which land units you'd like to move into the conquered sector, then all of your units will move in at once, and they will be interdicted in the same way as though they were being moved using the "march" command, including the danger of stepping on land mines. Note that there is no post-attack interdiction and no danger of stepping on land mines if the INTERDICT_ATT option is disabled (see version).

Charge the aggressor BTU's.
The BTU cost is equal to 0.5 + (the total number of casualties) * 0.015.