Power output and drain

Features & systems·Units, buildings & economy·Buildings & economy

Changed in 0.2.0

Each house keeps two totals: its output, the power its structures produce, and its drain, the power they consume. A house whose output is below its drain is short of power.

How the balance is computed

A house’s totals include every structure it owns that is placed on the map and not in limbo. A structure counts as soon as it is placed, so one still playing its buildup animation already adds both its output and its drain.

In a campaign game, a structure owned by a player-controlled house counts only after the player has discovered it. A base handed to the player by a trigger therefore adds nothing until the player sees it.

Writing the assignments

This example defines a power plant, a structure that consumes power, a plug for the plant, and the two [General] settings that govern a shortfall. The values are examples; the linked key pages give the defaults.

rules.ini

[MYPOWER]        ; example power plant
Power=100
Upgrades=1       ; upgrade slots this structure offers

[MYSAM]          ; example structure that consumes power
Power=-50

[MYTURBINE]      ; example plug for MYPOWER's upgrade slot
PowersUpBuilding=MYPOWER
Power=50         ; added to the host's output before damage scaling

[General]
DamageDelay=2            ; game minutes between damage ticks while short of power
MinProductionSpeed=0.75  ; lowest production multiplier a shortfall can impose

What each structure contributes

A structure’s output is its type’s positive Power= plus the positive Power= of every plug installed in it. A plug is a structure type with PowersUpBuilding=, installed into one of the host’s upgrade slots. The sum is multiplied by the structure’s current strength as a fraction of its maximum and rounded down.

A structure’s drain is the size of its type’s negative Power=, plus the drain of its plugs. Damage does not change it.

The table shows what affects each total. A stun is an EM pulse disabling the structure for a set number of frames.

	Output	Drain
Type	positive Power=	size of a negative Power=
Plugs	added before scaling	added
Damage	scales the total, rounded down	ignored
Switched off	nothing	nothing
Stunned	unchanged	unchanged

Damage reduces output from the first point lost. A plant with Power=100 supplies 99 at 999 of 1000 strength, and nothing at 1 strength. Because drain does not fall with damage, a base under attack loses output while its demand holds steady, and it can become short of power.

Only switching a structure off removes it from both totals. An EM pulse does not switch a structure off, so a stunned plant keeps supplying power and a stunned consumer keeps drawing it.

When the tally is rebuilt

A house recalculates both totals on its next update after any of these events:

• one of its structures changes strength;
• a structure finishes its buildup or is captured;
• a structure is taken off the map or changes owner;
• a plug is installed or sold;
• a structure is switched on or off;
• a human player discovers a structure.

After recalculating, the house:

• starts or stops its structures’ power-dependent animations, lights, fences and cloaking fields to match the new balance;
• recalculates the speed of its factories;
• rechecks whether its radar should be up;
• rechecks its superweapons, if the house has just become short of power or just stopped being short.

The power fraction

The power fraction is output divided by drain, capped at 1:

• 1 when output is at least drain;
• 1 when drain is 0, even with no output;
• 0 when output is 0 and drain is above 0;
• otherwise, output divided by drain.

A house is short of power exactly when its fraction is below 1.

Surplus buys nothing

The fraction is never above 1, so a house producing twice its drain is in the same state as a house producing exactly its drain. Extra output only protects against losing a plant or taking damage.

Switching a structure off

Players enter power mode with Power Mode or the sidebar’s power button. The power cursor offers the toggle only over an object that passes all of these tests, in this order:

• it belongs to a player-controlled house;
• it is a structure;
• its type is Selectable=yes;
• its type is not a deployed vehicle (one with UndeploysInto= without being ConstructionYard=yes);
• its type is TogglePower=yes;
• Any of: its type has drain, or its type is Powered=yes.

Even where the cursor offers it, a switch order for a FirestormWall=yes structure is refused.

A Turn off building trigger action or a scenario’s structure record can switch off any structure whose type has drain or is Powered=yes. They ignore TogglePower. A TogglePower=no structure switched off this way cannot be switched back on by the player.

A stunned structure cannot be switched on.

Switching a structure off:

• removes it from both totals;
• turns off its light source;
• starts shrinking its cloaking field;
• drops its laser fences;
• stops its powered animations;
• refuses units that try to dock with it, such as harvesters at a refinery or vehicles at a repair depot;
• makes its house recheck what it can produce, if the structure is a factory;
• discharges an active firestorm wall, if it was the house’s last switched-on GDIFirestormGenerator.

A player-controlled house hears an announcement when a structure is switched off or back on.

While a player-controlled house’s structure is switched off, a marker is drawn over it unless its cell is shrouded or fogged.

What low power costs

Each effect below applies to every house, computer houses included, unless noted.

A computer house that is not following a map plan also tries to avoid a shortfall. It builds a power plant before a structure that would leave it short; AI base planning covers that rule and the margin it keeps.

The structure damage tick

While a house is short of power, its structures that consume power take 1 point of damage every DamageDelay game minutes. The house’s timer runs whether or not the house is short, so the first tick lands anywhere up to DamageDelay minutes after a shortfall begins. A shortfall that ends before the next expiry costs no damage.

When the timer expires while the house is short, each structure that passes all of these tests takes 1 point of damage through C4Warhead:

• the house owns it;
• its strength is strictly above ConditionYellow of its maximum;
• its type has drain.

The tick ignores the on/off switch. A switched-off structure still takes damage, although it no longer adds to the drain. The drain test reads the structure’s type only, so a structure whose drain comes entirely from its plugs is never damaged.

A shortfall wears a base down to ConditionYellow and stops there. With a 1-point tick, it destroys nothing. Raising MinDamage makes every tick larger, and a tick larger than a structure’s remaining strength destroys it.

Verses cannot soften the tick

The tick is not forced damage, so the warhead’s Verses table applies. A 1-point hit multiplied by any percentage below 200, including 0, still deals 1 point. Only 200 percent and above increases it. To exempt a structure, give its type Immune=yes.

Production

A house short of power builds more slowly. Its build time is divided by a production multiplier that depends on its power fraction:

Power fraction	Production multiplier
1	1
0.75 up to but not including 1	0.75
0.5 up to but not including 0.75	the fraction itself
below 0.5	0.5

If the multiplier is below MinProductionSpeed, it is raised to that value. A multiplier of 0.75 makes a build take a third longer, and 0.5 doubles it. The bottom row means a house with no output at all still builds at half speed or better.

Only the middle band tracks the shortfall

Between 0.5 and 0.75 the multiplier equals the fraction, so a house at 0.6 builds more slowly than one at 0.74. Above and below that band the penalty is flat. At the default MinProductionSpeed the floor equals the bottom step and changes nothing. Raising it lifts every step below the new value to that value.

The power division is one step in the build-time calculation. How long it takes gives the full order, including BuildSpeed, the country and difficulty BuildTime multipliers, MultipleFactory, and WallBuildSpeedCoefficient.

Every recalculation of the balance updates the speed of the house’s factories. A build in progress keeps the progress it has made and continues at the new speed, so low power slows it without restarting it, and restoring power speeds it up again. The delay between production steps cannot exceed 255 frames, so once a build reaches that limit a deeper shortfall slows it no further.

Low power never removes an option from the sidebar. It only slows production.

Cash income

A Powered=yes structure that produces cash pauses its income while its house is short of power, even if it draws no power itself.

Radar

Only the local player’s house can lose its radar map. The radar is up while all of these hold:

• no ion storm is running;
• the house is not short of power;
• Any of:
  • the scenario sets FreeRadar=yes;
  • the house owns a Radar=yes structure that is All of: switched on, out of limbo, on the map, and not being sold.

In a campaign game, a radar structure the player has not discovered does not count. A player who has been given the whole map keeps the radar whatever these tests say; observers and coach mode covers that rule.

A stunned radar can block a working one

The house checks its radar structures in the order they were created and stops at the first one that passes the tests above. That structure supplies the radar only if it is not stunned. A stunned radar found first therefore keeps the map dark even while a second, working radar stands beside it.

Superweapons

A superweapon that comes from a structure is enabled while its house owns a switched-on structure that grants it, through the structure’s type or through a plug. A stunned structure still counts. The weapon is disabled whenever its house is short of power.

A disabled weapon is suspended only if its type is IsPowered=yes. Suspension stops the charge timer where it stands, replaces the status text on the sidebar cameo with a hold caption, and refuses the targeting cursor. The weapon resumes when it is enabled again.

A weapon that becomes available while its house is short of power arrives suspended, even when it is IsPowered=no. It resumes once power is restored.

A weapon granted by the Add repeating special weapon trigger action no longer needs a structure, so low power never suspends it.

A charge-draining weapon loses its charge

When a suspended UseChargeDrain=yes weapon resumes, its timer restarts from a full RechargeTime. Any shortfall that suspends it, however brief, discards all the charge it had built up. Suspending it also brings down an active firestorm wall.

Defenses

Three separate tests decide whether low power stops a defense, and they treat TogglePower differently.

1. Out of service. A structure is operational unless any of these holds:

   • it is switched off;
   • it is stunned;
   • its strength has reached zero;
   • All of: its type is Powered=yes, its type has drain, its type is TogglePower=yes, and its house is short of power.

   A structure that is not operational cannot fire. Spotlights, laser fences, sensor-array refreshes, cloak generators, and the choice of which EM pulse cannon fires use the same test.

2. Weapons. An operational structure still cannot fire while its house is short of power if its type is Powered=yes and has drain. This test ignores TogglePower, so a Powered=yes, TogglePower=no defense stops firing even though it remains operational.

3. SAM tracking. A SAM=yes launcher that is Powered=yes with drain stays in its ready state while its house is short of power, so it never turns toward its target.

The second test also stops a Charges=yes defense from starting a charge.

Fields, fences and lights

• A CloakGenerator=yes structure that stops being operational shrinks its field ring by ring. It regrows the field the same way, out to CloakRadiusInCells, once it is operational again and, for a Powered=yes type, once its house is no longer short of power. A generator that stays operational, such as one left at Powered=no, keeps its field through any shortfall.
• Laser fences are rechecked at every change to the balance. A fence run is up only while the posts at both ends are operational, so low power at either end drops the whole run.
• A spotlight is neither drawn nor able to notice an intruder unless its structure is operational.
• When a house is not short of power, every structure it owns runs its powered animations and powered lights, including a structure that is switched off. When the house is short, only a type that is Powered=yes, has drain, and is TogglePower=yes stops them.

A sensor array does not go dark with the rest of the base

A power change does not remove sensor coverage. A SensorArray=yes structure keeps its cells until it is taken off the map or captured. Low power matters only to an array that has not marked its cells yet: an array that finishes building while it is not operational marks nothing until any house’s cloak field finishes growing while it is operational.

A TogglePower=no defense is silenced but stays lit

The animation shutdown and the out-of-service test both spare a TogglePower=no structure, but the weapon test does not. Such a defense holds fire through a shortfall while its animations and lights keep running, so it looks like a working turret.

Player feedback

The game announces low power while all of these hold:

• the house is the local player’s;
• the house’s announcement timer has expired;
• the house is short of power;
• it owns at least one structure of a BuildConst type, switched on or not.

The announcement plays the warning, shows its on-screen text for MessageDelay minutes, and restarts the timer with SpeakDelay minutes.

The height of the sidebar power bar grows with the size of the Power= rating of every structure the player owns, producers and consumers alike, leaving out plugs. A damaged or switched-off structure still adds its full rating to the height.

The bar’s colors follow the real totals. While the house is short of power, the whole bar is red. Otherwise, the drain shows red, the first 100 points of surplus show yellow, and any surplus beyond that shows green.

Scripting

The Power Low trigger event holds while the named house is short of power.

The Turn off building and Turn on building actions use the same switch as the power cursor, for every structure on the map that carries the trigger’s tag. Turn off building affects only structures that are on, and Turn on building only those that are off.

Parsed settings without effect

The production ladder above is fixed in the engine. WorstLowPowerBuildRateCoefficient and BestLowPowerBuildRateCoefficient in [General] are read but never used. Changing either setting has no effect. The ladder’s fixed 0.75 step happens to equal the default of BestLowPowerBuildRateCoefficient.

Related settings

Filter keys

26 of 26

Key	Description	Value	When omitted
BuildSpeedglobal rules	The multiplier that turns an object's cost into its base build time.	floating point	1
BuildTimeHouseType, difficulty settings	The build-time multiplier a country applies to everything it produces, or the one a difficulty setting applies.	floating point	Varies by type
C4Warheadglobal rules	The warhead used for damage that no weapon deals, such as a demolition charge.	class	none
CloakGeneratorBuildingType	Whether the structure projects a cloaking field over the cells around it.	boolean	no
CloakRadiusInCellsBuildingType	The radius in cells of a cloak generator's field or a sensor array's coverage.	integer	20
ConditionYellowglobal rules	The fraction of maximum strength at or below which an object counts as damaged.	floating point	.5
DamageDelayglobal rules	Minutes between the damage ticks a house takes while it is short of power.	floating point	1
FreeRadarscenarios	Whether the scenario grants the radar map without a radar structure.	boolean	no
ImmuneNo effect in some scopes12 applicable types	Exempts the type from every damage path that is not applied as forced.	boolean	Varies by type
IsPoweredSuperWeaponType	Whether the superweapon stops charging while its house is short of power.	boolean	yes
LaserFencePostBuildingType	Whether the structure anchors laser fence segments run out from it.	boolean	no
MessageDelayglobal rules	How long most on-screen messages stay visible.	floating point	.6
MinDamageglobal rules	The smallest damage a warhead may deal to a target close to the impact.	integer	1
MinProductionSpeedglobal rules	The floor the low-power production multiplier is held to.	floating point	.5
MultipleFactoryglobal rules	The build-time multiplier each factory past the first applies to production of its category.	floating point	1
PowerBuildingType, Tiberium	Power a BuildingType contributes to its house, negative for consumption, or the damage a Tiberium type deals.	integer	0
PoweredBuildingType	Whether the structure stops working while its house cannot meet its drain.	boolean	no
PowersUpBuildingBuildingType	The ObjectType ID of the structure this type plugs into as an upgrade.	string	none
PowersUpToLevelBuildingType	How many upgrade slots the plug consumes at once, or -1 for one slot in the next free position.	integer	-1
RadarBuildingType	Whether the structure can supply the player's radar map.	boolean	no
SensorArrayBuildingType	Whether the structure marks the cells around it as sensed, revealing cloaked objects standing there.	boolean	no
SpeakDelayglobal rules	Minutes an EVA announcement waits before it may be repeated.	floating point	2
TogglePowerBuildingType	Whether the player may switch this structure on and off.	boolean	yes
UpgradesBuildingType	How many upgrade plugs the structure accepts.	integer	0
VersesWarheadType	The percentage of a weapon's damage the warhead delivers against each armor class, in armor order.	string	100%,100%,100%,100%,100%
WallBuildSpeedCoefficientglobal rules	The multiplier applied to a wall's build time.	floating point	.5

Related resources

• EMP pulseFeature or system
• AI base planning and buildingFeature or system
• Power Low...Trigger event
• Turn off buildingTrigger action
• Turn on buildingTrigger action
• Building animationsFeature or system
• Cloaking and detectionFeature or system
• Laser fences and the firestorm wallFeature or system
• Shroud, fog and the radar mapFeature or system
• Observers and coach modeFeature or system
• Buildings that produce cashFeature or system
• Production and factoriesFeature or system
• Sidebar and build queueFeature or system
• SuperweaponsFeature or system

History

1. Changed0.2.0In development

   Keep charging defenses working through low power

2. Changed0.2.0In development

   Watch a multiplayer match as an observer

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