Editing Stealth (section)

==Detection==
Guards, drones, and security devices rely on a wide range of sensors to detect intruders.

===Visual detection===
====Enemies====
Guards and drones can spot your team visually. Each enemy has a vision cone; hover over an enemy to see the cone depicted in the [[HUD]] in translucent red with radial lines. The cone also displays in the [[HUD]] during the enemy's turn. The cone is typically 90 degrees wide and 18m long. The animation of a guard often shows them glancing around, stretching, and doing other idle things, but their attention is not actually moving. The region they can see is fixed unless the guard is moving or turning. The vision cone displayed in the [[HUD]] is the actual area they are looking at. The cone is depicted at knee height on the guard.

Vision can be blocked or obstructed by obstacles in the cone of vision. Solid objects such as walls and tall stacks of materials will block vision entirely. This is displayed in the HUD as sections of the vision cone missing. Shorter objects and non-solid objects such as shelving only partially obstruct vision.  Obstructed vision is displayed in the HUD as hatched yellow sections of the vision cone. A merc in the solid red section of the vision cone will be seen. A merc in a hatched yellow section of the vision cone will be seen if they are standing or sprinting but will not be seen if they are crouched or sneaking. Use the [[HUD]] camera view controls to carefully check whether a movement path enters the obstructed or unobstructed vision of an enemy.

If a standing merc has an obstruction between them and a moving guard and the guard's vision cone comes across the merc, the merc will automatically toggle to crouch mode to get out of sight. If a merc in the obstructed section of a guard vision cone toggles from crouching to standing, the player will be warned once and the merc will toggle back t crouching. If the merc toggles to standing a second time, they will stand up and the guard will see the merc.

Vision between platform levels is poor. A guard usually will not see a merc that is sneaking on a level above or below the guard, unless whoever is on the higher platform is near the edge. The vision cone and obstructed sections displayed on the [[HUD]] do not account for differences in altitude and the edges of platforms.

If a merc passes through the edge of an enemy vision cone only briefly, the HUD may flash a small red cone flash directly in front of the enemy. The size of the flash indicates how strong the near-detection was. If the red cone flash does not reach 50%, the movement was not enough for detection threshold and the enemy does not become suspicious. The merc got lucky.

If the red cone flash reaches 50% but less than 100%, their [[alert status|Alert Status]] will rise to Suspicious and the merc's [[detected status|Detected Status]] will rise to Suspected. The pending [[security tally|Security Tally]] will go up by one or more points. The guard will immediately turn to look in that direction, regardless of whether they have action points remaining, without waiting for the end of the current character's turn. It is possible that in turning, the guard will get a better look and spot the merc. Otherwise, on their next turn, the guard may move toward the source to investigate. After they reach the location, they will spend a couple turns moving around the area looking for the source. If they don't find anything, the guard will move back to their post. If they were on patrol, they will head to the next waypoint in their patrol.

If guard with an [[alert status|Alert Status]] below Spotted sees a team member, the guard's [[alert status|Alert Status]] will jump to Spotted and the merc's [[alert status|Detected Status]] will jump to Spotted. The pending [[security tally]] will go up one or more points. The guard will then try to engage in [[combat]].
====Cameras====
Cameras can also detect your team visually. Cameras have a vision cone which is marked in the [[HUD]] with a red outline filled with translucent red fading with distance. The vision cone is depicted at waist level. There are two types of cameras. The most common type, the short-range camera, typically has a vision cone 90 degrees wide and 10m long. The other is a long-range camera with a narrower vision cone and more than 20m long. Long-range cameras are frequently inactive until the [[Security AI]] decides to activate them during a security escalation.

Both types of cameras are typically oriented to the cardinal directions. Cameras can be mounted high on a wall or on top of tall poles. Cameras will often rotate once a turn. Some cameras rotate back and forth. Pole-mounted cameras in the middle of a room may rotate in a full circle; the most common direction for rotation is clockwise.

Cameras are blocked or obstructed by the same things as guard vision. Blocked and obstructed regions of the vision cone are '''not''' depicted in the [[HUD]]. The height of the camera lets them see over some obstacles. This can make it hard to tell whether a particular location or movement path will be detected by the camera. A warning will display if the camera might see you, but it may signal false positives.

A merc will automatically duck behind cover if a guard looks in their direction, but there is no automatic protection from cameras. A merc will not automatically toggle to crouch mode if a camera swings in their direction. If a moving camera sweeps past a merc, briefly putting the merc in the detection zone, the camera can spot the mercenary. The sectors between the cardinal directions of a long-range camera are not safe.

The area below the camera mount is a blind spot. This blind spot is not depicted in the [[HUD]]. A merc can safely pass through a camera vision cone if they keep close to the camera mount.

If a camera spots a merc, the pending [[security tally|Security Tally]] is raised by one or more points and the camera will send a notice to the [[Security AI]] at the end of the turn. The [[alert status|Detected Status]] of the merc may be increased. The Security AI will usually send a guard on the next turn to investigate; the guard's [[alert status|Alert Status]] will be raised to Alerted. Alerted guards will not return to their post or patrol.
===Audio detection===
Guards and drones can hear your team when they are moving. The base range at which an enemy can hear a merc sprinting is 10m. For reference, the tiles found on many floor surfaces are 2m square. Certain [[character traits]] and [[Talents]] can modify the base detection range. You can enter sneaking mode by toggling the C button. While you are sneaking, the audio detection range is cut in half, so a merc with no modifier for Move Detection Radius can be heard sneaking at a range of 5m.  A merc with the Thief trait has a modifier of -2m Move Detection Radius; they can be heard sprinting from a distance of 8m or sneaking at a distance of 4m.  Noise modifiers are additive, so multiple traits and talents can reduce Move Detection Radius even further. A total of -7 modifier would allow a merc to quietly get within blade range of an enemy.

Gunfire can be heard at much longer distances. Depending on the firearm, unmodified guns can be heard at ranges from 25m to 60m. Many [[weapons]] can take a silencer or suppressor as a barrel [[Weapon Mods|mod]] to reduce the Noise radius. Silencers usually reduce max optimal range. Suppressors add critical damage bonuses because they cut down muzzle flash. The Noise attribute of a [[Weapons|weapon]] displays the detection radius accounting for any attached [[mods]]. [[Blades]] make no sound at all, making them an excellent, if extremely short range (typically 2m), option for stealth.

[[Grenades]] can usually be heard throughout a level. It is usually a bad idea to use a grenade if you want to remain in stealth, though it will probably attract a lot of guards away from their posts if that is the intent.

Noise travels through walls with no obstruction.

A guard who hears a noise will immediately turn toward the noise, regardless of whether they have action points remaining, without waiting for the end of the current character's turn. The guard's [[alert status|Alert Status]] will rise to Suspicious. If the noise was a merc moving, their [[alert status|Detected Status]] will rise to Suspected. The pending [[security tally|Security Tally]] will rise by one or more points. On their next turn, the guard will usually move toward the source to investigate. If there are obstructions such walls in the way, it can take a few turns for them to reach the location of the sound. If the location is unreachable, they will get as close as they can. After they reach the location, they will spend a couple turns moving around the area looking for the source. If they don't find anything, the guard will move back to their post. If they were on patrol, they will head to the next [[waypoint]] in their patrol.
===Other detection===
There are many other types of detectors that use various sensory modes to detect intrusion.
; Pressure plates
: Detects any unauthorized person stepping on the sensor zone. An active pressure plate is depicted in the [[HUD]] as a red mesh region across a pinch point. If the sensor is disabled, the mesh turns gray.
; Laser fences
: Detects any unauthorized person passing through the sensor wall. A laser fence is depicted in the [[HUD]] as a vertical array of horizontal red lines forming a detection zone between two towers. Most laser fences are initially harmless except for detection, but the [[Security AI]] can activate "lethal" mode under elevated security protocol. The laser fence will then cause damage (usually not lethal) to any unauthorized person crossing through, in addition to detection.
; Motion detectors
: Motion detectors detect any unauthorized person sprinting through the sensor area. Motion detectors will not detect anyone sneaking through the zone, but the zone is usually large. A motion detector zone is depicted in the [[HUD]] as a red circle around the detector. Motion detectors are blocked by solid objects in the same way as a [[Cameras|camera]]. The [[HUD]] display does not mark the blocked regions of a motion detector.
; Bio-Scan Field
: A Bio-Scan Field detects life signatures within a large area. The [[HUD]] depicts this as a blue fuzzy glow in the air. The field will trigger an alert if too many bio-signatures are detected; the usual limit is 1 signature at a time. If more signatures are detected, the detector raises a pending [[Security Tally]]. If the extra signatures leave the field before the end of the [[Turn]], the pending [[Security Tally]] is removed and the [[Security AI]] is not informed.
; Mines
: A mine is a kind of [[Motion detectors|motion detector]] that will trigger an explosion if an unauthorized person enters the sensor zone. It will detect intruders both sprinting and sneaking. The mine does not directly add [[Security Tally]], but the explosion is likely to be heard by many enemies.
All of these sensors (except mines) will increase pending [[security tally|Security Tally]] by one or more points when triggered. The [[alert status|Detected Status]] of the merc may be increased. When the Security AI is notified of a detection, it will usually send a guard to investigate; the guard's [[Alert Status]] will be raised to Suspicious.