Engineers, capture and sabotage

Features & systems·Combat & weapons·Combat & targeting

Changed in 0.1.0

Almost everything below turns on which mission a soldier is in — the state that says what it is doing at this moment, and the rules section named after it. Target selection introduces both.

Who can walk in

Six settings on an InfantryType decide what a soldier does when it reaches whatever it was sent at.

Setting	What the soldier does on arrival
Engineer=yes	Restores an allied structure, takes or damages a non-allied one, repairs a bridge
C4=yes	Arms a Repairable=yes structure with a demolition charge and walks away
Agent=yes	Infiltrates a structure and reports what it holds
Infiltrate=yes	Nothing on its own. It is what lets a soldier be given a structure as a target and a destination at all
VehicleThief=yes	Takes the vehicle it was sent at
Thief=yes	Takes a non-allied vehicle it is walking toward, under any mission

Infiltrate=no cannot be written on an engineer or a demolition type

C4=yes and Engineer=yes each force the infiltrate flag on, and they do it immediately after the section’s own Infiltrate line has been read. An explicit Infiltrate=no in such a section is overwritten in the same pass and changes nothing. The forcing also outlives the flag that caused it: a later rules layer that writes Engineer=no over an engineer type clears the engineer behavior but leaves the infiltrate behavior in place, so the type still takes the enter cursor over a Capturable=yes structure, still walks in, and does nothing when it arrives. Agent=yes forces nothing, so a spy needs an explicit Infiltrate=yes or it is never offered a structure at all.

The cursor

An engineer over a structure

A deployed vehicle is a structure that names an UndeploysInto vehicle and is not a construction yard. The engine counts one as a vehicle rather than as a structure, and that distinction runs through the rest of this page.

A player-controlled engineer has cursor rules of its own. They apply to a structure meeting all of:

• Any of: it is not a deployed vehicle; it is IsMobileWar=yes.
• Any of: it is Repairable=yes; it is IsMobileWar=yes.

An IsMobileWar=yes structure therefore reaches these rules whatever else it is, and every other structure has to clear both groups. For one that does, the table gives the cursor produced.

Structure	Cursor
A BridgeRepairHut=yes type	The repair cursor when a bridge near it can be repaired, the refusal cursor otherwise
An allied structure at full Strength	The refusal cursor
An allied structure below full strength	The repair cursor
A non-allied Capturable=yes structure above EngineerCaptureLevel	The damage action, which carries no cursor art of its own
A non-allied Capturable=yes structure at or below that fraction	The enter cursor

The full-strength test compares against a figure fixed at 1 in the engine and reads the strength live, so the repair cursor appears the moment an allied structure drops a single point.

Anything these rules do not settle falls through to the general rewrite every Infiltrate=yes soldier shares — both a structure the two groups above rejected and a non-allied structure that clears them but is not Capturable=yes, which matches no row. That rewrite offers the enter cursor over a non-allied Capturable=yes structure with no strength test at all. That is the route a Repairable=no structure takes — a barrel, a mine, a wall — and the route a spy takes for everything. It withholds the cursor when no cell adjacent to the structure’s footprint sits in the same movement zone as the soldier, which is what keeps it off a naval yard that no land route reaches.

The capture threshold moves the cursor and nothing else

EngineerCaptureLevel picks between the enter cursor and a damage action, and the click folds the repair cursor, the damage action and the enter cursor into a single capture order before it is issued. What happens at the structure is decided again from the flags found there. The damage action has no cursor art of its own and falls back to the ordinary pointer, and at the engine default of 1 it cannot be produced at all, because a structure’s strength as a fraction of its maximum can never rise above 1.

With fog of war switched on, an engineer’s cursor over a cell that holds a fogged structure record ignores ownership, strength and Capturable alike: a bridge repair hut takes the repair or refusal cursor and any Repairable=yes type takes the enter cursor. That click issues the capture order against the cell rather than against an object.

A commando over a structure

For a player-controlled infantry with C4=yes or the C4 ability, an attack cursor over a structure that is not a deployed vehicle becomes the demolitions cursor when the type is Repairable=yes and stays an attack cursor when it is not — which is how a commando shoots a barrel and bombs everything else. Force fire reaches an allied or own structure the same way, because holding it produces the attack cursor there in the first place.

A vehicle thief over a vehicle

A player-controlled VehicleThief=yes soldier takes the enter cursor over any non-structure counted as a vehicle, which includes a landed aircraft. An IsTrain=yes type takes the select cursor instead. The ownership test is house identity rather than alliance, so the cursor appears over an allied house’s vehicle as readily as over an enemy’s.

The harvester truce never protects a vehicle from a thief

The clause meant to exempt a harvester while the truce is on tests the vehicle standing on the map for membership in HarvesterUnit, which lists types rather than the objects made from them. A runtime vehicle can never be equal to a type definition, so the test always comes out false, the exemption never fires, and the enter cursor appears over a harvester under every setting. The equivalent exemption in target selection reads the vehicle’s type instead, and that one does hold a harvester off.

What the click issues

The three sections above each settle a cursor. This table takes over from there: the left column is what those rules produced and the right is the order a click on it issues. Three of them share the first row, which is why what happens at the structure is settled again on arrival rather than by the cursor the player saw.

What the cursor test produced	Order issued
Repair, enter, or the damage action, over an object	The capture mission, with the object as the destination
Demolitions	The sabotage mission, with the object as the destination
Enter, over a cell	The capture mission, with the cell as the destination
Area guard, over a non-allied Repairable=yes structure, from a C4=yes soldier	The sabotage mission
Refusal	Nothing

Both missions are serviced on the cadence their own Rate sets in the [Capture] and [Sabotage] sections, plus a jitter of up to two frames. A vehicle handed either order converts it to an attack. An Infiltrate=yes soldier given a structure as an attack target converts that order into the capture mission, and one with C4=yes or the C4 ability converts it into sabotage first only when the structure is Repairable=yes.

Walking in

Everything in this section happens when the soldier finishes a move onto a cell while on the capture, area guard or patrol mission. Area guard and patrol are in that gate, which is how a computer engineer restores a structure without an explicit order.

An infantry on the capture, sabotage or enter mission may step into the cell holding its destination, and an engineer may do so on guard, area guard and patrol as well; a vehicle thief gets the same allowance for any non-IsTrain=yes vehicle it is aimed at. Under the capture, enter, area guard and patrol missions the walking locomotor will also let it claim a sub-cell position — one of the three standing places a cell offers infantry — that another soldier already holds. An Infiltrate=yes type is exempt from the check that would otherwise discard a destination lying in another movement zone.

The vehicle branch

The first test is on the destination alone: a live object counted as a vehicle. There is no flag test, no alliance test and no Capturable test. While the soldier is off the cell, the destination is simply re-aimed at the vehicle. Once the two stand on the same cell, this runs in order:

1. the entered trigger on the vehicle springs;
2. the vehicle detaches from everything tracking it;
3. ownership changes;
4. infantry heading into the vehicle scatter, which happens only where it is in fact a deployed vehicle;
5. the soldier’s tag moves onto the vehicle, if that tag is transferable;
6. the soldier’s own destroyed-anything trigger springs;
7. the soldier is deleted.

A soldier’s tag is the scenario tag attached to it — the record that binds a trigger to an object. It is transferable when the trigger behind it, or any trigger linked behind that one, sets the transferable field of its own record. A tag that is not transferable does not move; step 7 deletes the soldier still carrying it.

An engineer takes a mobile war factory outright

A deployed vehicle counts as a vehicle here. Because this branch runs ahead of all the engineer handling and applies none of its tests, an engineer that reaches a deployed mobile war factory changes its owner on the spot — at any strength, whatever Capturable says, and including an allied one. The allied case is reachable straight from the cursor: a damaged allied IsMobileWar=yes structure offers the engineer’s repair cursor, and that click issues the same capture order.

Restoring an allied structure

An engineer that reaches an allied structure restores it to full strength at no cost, and that also forces the repair flag off. The damage animation state is re-evaluated on the new strength. Nothing else about the structure changes.

Repairing a bridge

A BridgeRepairHut=yes structure replaces both the restore and the capture branches, so a hut is never restored and never changes hands whoever owns it. EVA announces the repair for a player-controlled house. The repair to run is chosen from the five-by-five block of cells centered on the soldier: a rail bridge tile anywhere inside it selects the rail repair, and the road repair runs otherwise. Every infantry then drops the hut as a target, and infantry heading into the cell scatter.

Capturing a non-allied structure

For a non-allied Capturable=yes structure the entered trigger springs again, the losing house is marked as having been robbed, the soldier’s tag is attached to the structure if it is transferable, ownership changes, and infantry heading into the cell scatter.

That mark is the one the Thieved by… trigger event tests. It is set here and nowhere else — not by a stolen vehicle — and nothing ever clears it, so once a house has lost one structure to an engineer the mark stands for the rest of the match. Nothing acts on it, though: the event is never announced to a trigger and so is never satisfied, and no other part of the game reads the mark.

Damaging it instead

The engineer damages the structure instead of taking it under all of:

• the game is not a campaign game;
• the lobby’s multiplayer engineer option is on;
• the structure’s strength fraction is above ConditionRed.

Capturable is not consulted on this branch.

damage one engineer deals

damage = min(Strength − MaxStrength × ConditionRed / 2,
             MaxStrength × (1 − ConditionRed / 2) / 2)

The figure is applied as forced damage with C4Warhead and the engineer as the source. Forced damage skips the warhead’s own effectiveness table, the house and object armor biases, the veteran armor bonus and Immune=yes alike, so the structure takes the whole figure. At the default ConditionRed of 0.5 that is a bite of at most 37.5% of maximum strength, and the branch stops as soon as the structure is at or below half strength:

Engineer	Strength before	Strength after
First	100%	62.5%
Second	62.5%	25%
Third	25%	Captured

ConditionRed therefore sets both the band in which the branch runs and the size of the step, and at 1 or above the branch is unreachable, since the strength fraction can never exceed it.

This branch reads C4Warhead without checking it

A structure that crosses the half-strength or the red-strength mark runs the fire-and-smoke handling, which reads the warhead it was damaged with and never tests it first. C4Warhead holds nothing until [CombatDamage] names one, so with the setting absent the second engineer’s hit — the one that crosses both marks — reads through a warhead that was never supplied. Name a C4Warhead before switching the multiplayer engineer option on.

Infiltrating it

A soldier that is not an engineer does anything at the structure only when it is Agent=yes. EVA announces the infiltration for a player-controlled house, and the house is recorded as spying on that structure: a spied structure shows its status overlay whenever the spying player selects it, and a spied factory also draws its current product through the same cameo palette as the sidebar.

A Radar=yes structure adds far more. Spying on one marks the whole owning house as radar-spied, and while that mark stands every sight the victim’s objects take is credited to the local player instead — a standing share of the victim’s vision rather than a single reveal. The mark is recomputed only when a spied radar structure is destroyed or changes hands, and capturing a structure clears the capturing house’s own spy mark on it. Spying on a structure with positive Power adds nothing but a redraw of whichever spied structures the player has selected at that moment.

The soldier is consumed

Every path through the structure branch deletes the soldier, including the paths where nothing at all happens: an engineer at a non-capturable non-allied structure inside a campaign, and any soldier that is neither an engineer nor Agent=yes. Arming a demolition charge is the one entry path on this page that leaves the soldier alive.

What changes hands

Change of ownership is one shared routine, and it runs the same way for a structure, a vehicle and an aircraft.

• The object is booked as a kill with no source attached. The capturing house collects the score points and nothing gains experience; the object keeps the rank it was already carrying.
• The losing house’s inventory counts fall and the new owner’s rise, except on an Insignificant=yes type, which changes hands without moving between the two tallies at all.
• The object’s current target and destination are cleared, it detaches from everything tracking it, cell threat moves from one house to the other, and it re-enters idle behavior.

A structure adds to that:

• The storage capacity its Storage declares moves to the new owner, and so does whatever the structure is holding — straight into the new owner’s spendable credits. The loser simply loses it; it is not booked as harvested on the way out.
• Anything loaded inside is captured with it. So is anything in radio contact at a weapons factory, or within a quarter of a cell of the docking coordinate; anything further off is told to run away and contact is broken.
• Production in progress is abandoned. The object under construction is deleted and the money spent on it so far is refunded to the losing house.
• Both houses recount their factories, and a captured construction yard moves between their construction-yard lists. A player who has just lost the last of them also loses any placement cursor in progress.
• The structure re-opens for business as a capture rather than as a new build, which skips the two gifts a fresh structure hands out: a captured FreeUnit structure yields no free vehicle and a captured helipad no free aircraft.
• The repair flag is cleared, a cloak generator’s radius is reset and re-enabled if it still has power, and EVA announces the capture when either side is under player control.
• The losing house records the structure as its recapture target, which is what its own engineers head for.

A computer house sells what it captures

Outside a campaign game, a capture by a non-human house refunds and removes every upgrade plugged into the structure and then sells the structure itself. The only exception is a structure that produces buildings and that the capturing house now owns at most one of. A type with no build-up animation cannot be sold, so there the upgrades are still stripped and refunded and the bare structure stays — except a firestorm wall section, which is removed outright with no refund.

Capture leaves three lasting marks besides the change of owner. A captured structure halves the number of survivors it will ever produce and worsens their odds, it never returns the [General] Engineer type among its crew whether it is destroyed or sold, and it satisfies the computer’s last repair gate on its own, without the structure having been marked for repair. Nothing clears the captured mark, so recapturing it back undoes none of them.

Rank, abilities and the elite weapon survive the change intact. Strength is neither restored nor reduced. And an armed demolition charge keeps its countdown running through the whole thing.

Demolition charges

Arming a structure

Arming requires the sabotage mission, a Repairable=yes structure as the destination, and the type still carrying that flag when the soldier arrives. A stale or directly assigned sabotage mission against another structure is canceled and the soldier returns to idle behavior. There is no alliance test, so force fire can still send a saboteur against a qualifying structure belonging to its own house. Unless the structure is already deconstructing, the charge is set, the structure begins flashing as a designated target, the countdown is set to C4Delay minutes’ worth of frames — 27 frames, about 1.8 seconds, at the default — and the saboteur is recorded against it. The saboteur then clears its destination, uncloaks, takes a rearm delay and scatters away from the structure’s center.

Detonation

When the countdown reaches zero the structure takes damage equal to its current strength, applied as forced damage with C4Warhead and sourced to the saboteur — or to nobody, if the saboteur died first, which also costs its house the kill credit.

A charge cannot be defused

Nothing anywhere clears the armed state. Repairing the structure, restoring it with an engineer and capturing it all leave the charge armed and the countdown running. A sale requested explicitly — by a computer house, by a trigger action, or by the capture sell-off above — is refused while a charge is armed, but a player’s own sell order does not consult it and begins deconstruction with the countdown still going.

Survivors

The count is Cost × SurvivorRate / SurvivorDivisor, clamped to between 1 and 5, doubled in the divisor for a captured structure, and zero for a type that is not Crewed=yes. Each cell of the footprint then rolls once for one survivor, at odds set by two independent facts about the structure: whether it was ever captured, and whether a live saboteur is on record against it. Arming a charge is what puts a saboteur on record, and the saboteur’s own death takes it off again.

Roll per footprint cell	No saboteur on record	Saboteur on record
Never captured	One in three	One in two
Captured	One in nine	One in eight

Being captured is by far the heavier of the two: it costs more than the saboteur gains, so a captured structure is a poorer source of survivors even with a charge ticking on it. The survivors attack the saboteur on record if there is one; otherwise a human house’s wander off and a computer house’s go hunting.

A structure destroyed by its own charge produces none of them. The detonation is forced damage, and a forced destruction is marked survivorless before the count is taken, so the improved right-hand column is only ever reached on a structure that something else finished off first — and only while the saboteur is still alive to hold its place on the record.

Stealing a vehicle

VehicleThief=yes and Thief=yes are separate features with separate cursors, targeting and limits. They meet in one place: both stamp the vehicle with the type that took it, which is what puts a hijacker back on the map when the stolen vehicle dies.

A VehicleThief=yes soldier is the one with a cursor. It takes the vehicle through the vehicle branch, and a computer house turns its hunt into a capture order and leaves it on area guard when idle. Two consequences outlive the theft:

• The stolen vehicle counts against the thief type’s BuildLimit for as long as it lives, so a hijacker limited to one cannot be rebuilt while its prize survives.
• When that vehicle is destroyed, the hijacker steps back out. It is recreated at the wreck with a strength between 5 and half its maximum, with no Crewed=yes requirement and no crew-escape roll to pass, hunting for a computer house and standing guard for a human one.

A vehicle thief also loses its target outright when the vehicle it is chasing deploys into a mobile war factory or a construction yard, while every other object chasing that vehicle is handed the new structure instead.

Thief=yes has no cursor anywhere. Its steal runs on every one of the soldier’s own passes regardless of mission, and needs a non-allied vehicle as the movement destination: within half a cell and one height level the vehicle’s entered trigger springs, radio contact breaks, the thief’s tag moves across if it is transferable, ownership changes and the thief is deleted. Beyond that it re-aims at the vehicle whenever the vehicle wanders off. The flag also widens what its owner scans for.

Computer-controlled engineers

A computer house aims engineers through target selection, which covers the scanning rules, the fifteen-cell shortcut to the house’s recapture target, and the filter that lets an engineer accept a damaged ally and reject everything else. Four mission conversions sit outside that:

• A hunt becomes a capture order for an engineer that is neither C4=yes nor carrying the C4 ability, and for a vehicle thief.
• A hunt becomes a sabotage order for a C4=yes soldier whose target is a Repairable=yes structure.
• Guard and area guard become a sabotage order under the same condition, for a computer house only.
• A patrolling engineer drops an allied structure as a target once that structure climbs back above ConditionRed.

An engineer skips target scanning altogether on plain guard, and being shot at while standing on guard or area guard sends a computer-owned one hunting.

Settings without effect

EngineerDamage is read from [General] under its own name, but no gameplay path consults the figure it fills, so writing it changes nothing.

The sabotage handling has a second branch, for a saboteur whose destination is a bare cell rather than a structure, that fires three area explosions of BridgeStrength with C4Warhead at the soldier’s own position. No cursor produces that combination, because the cell branch of the click handler is never reached. The computer’s guard and area-guard conversions do not clear an existing destination, so a computer-owned saboteur can carry the mission with a cell destination and reach it that way.

Related settings

Filter keys

19 of 19

Key	Description	Value	When omitted
AgentInfantryType	Makes a soldier report on the structure it walks into rather than capturing it.	boolean	no
BridgeRepairHutBuildingType	Turns the structure into the one an engineer walks into to rebuild a destroyed bridge.	boolean	no
C4InfantryType	Makes a soldier arm a structure with a demolition charge instead of shooting at it.	boolean	no
C4Delayglobal rules	The delay in minutes between arming a demolition charge and its detonation.	floating point	.03
C4Warheadglobal rules	The WarheadType behind damage the engine deals without a weapon to draw one from.	class	none
CapturableBuildingType	Allows a structure to take the enter cursor and to change hands when an engineer walks in.	boolean	no
ConditionRedglobal rules	The fraction of maximum strength at or below which an object counts as critically damaged.	floating point	.5
CrewedAircraftType, BuildingType, InfantryType, UnitType	Allows the type to put a surviving infantry on the map when it is destroyed.	boolean	no
EngineerInfantryType, global rules	Whether a soldier restores and captures structures, or which InfantryType a destroyed structure hands back as an engineer.	boolean	Varies by type
EngineerCaptureLevelglobal rules	The fraction of maximum strength at or below which an engineer's cursor over a non-allied structure is the enter cursor.	floating point	1
InfiltrateInfantryType	Allows a soldier to be given a structure as a target and to be sent into it.	boolean	no
InsignificantNo effect in some scopes12 applicable types	Whether the object is kept out of its house's inventory tallies and its response to being attacked.	boolean	Varies by type
IsMobileWarBuildingType	Marks a deployed structure as a mobile war factory, which an engineer may work on and which may pack up at any time.	boolean	no
RepairableAircraftType, BuildingType, InfantryType, UnitType	Allows a structure to be repaired with the wrench, worked on by an engineer, and treated as a building by a commando.	boolean	yes
StrengthNo effect in some scopes12 applicable types	The maximum strength of most object types; wall overlays use it as a per-hit damage threshold.	integer	Partially documented
SurvivorDivisorglobal rules	The divisor applied to a structure's cost when its number of survivors is worked out.	integer	100
SurvivorRateglobal rules	The fraction of a structure's cost that decides how many survivors leave it.	floating point	.5
ThiefInfantryType	Makes a soldier take a non-allied vehicle it is walking toward.	boolean	no
VehicleThiefInfantryType	Makes a soldier take the vehicle it is sent at, and lets it walk into that vehicle's cell.	boolean	no

Related resources

• Repair and healingFeature or system
• Veterancy and promotionFeature or system
• Target selection and threat ratingFeature or system
• Destruction and debrisFeature or system
• All change houseTrigger action
• Entered by...Trigger event
• Destroyed, Buildings, #...Trigger event
• Destroyed, Units, #...Trigger event
• Spied uponTrigger event
• Destroyed by anything [not infiltrate]Trigger event
• Thieved by...Trigger event
• Building exists...Trigger event
• Destroyed by anythingTrigger event
• Destroyed by any houseTrigger event
• Spy on bldg @ waypt...Team script mission
• Change house...Team script mission

History

1. Changed0.1.0In development

   Require repairable structures for C4 sabotage

2. Changed0.1.0In development

   Draw infiltrated factory cameos in their own palette

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