Your 'Mech comes equipped with an advanced sensor suite that is capable of detecting enemy 'Mechs, analyzing their status and relaying that information to your allies. Without any modifiers you will scan an enemy 'Mech at a distance of 800 meters in a 120 degree cone to the front of your 'Mech torso. To target an enemy place your cross hairs over their sensor contact and press the target hotkey ("R" by default).
An enemy 'Mech will be in one of three sensor states.
- You have line of sight on an enemy but cannot see them on sensors. They are either out of range or are being covered by ECM (which essentially reduces the range of your sensors).
- The enemy has their weight class icon visible. They are either visible to your sensors and ready to be targeted, or are being actively targeted by an ally.
- The enemy has a red square around their sensor contact. You are actively targeting that enemy.
It is an essential habit to target the enemy you are fighting as it will:
- Show where the enemy is damaged
- Show what weapons the enemy is using
- Show their location on the mini map
- Give your allies this information
Any active sensor locks and targeting information is automatically shared between you and your allies. This can allow you to target enemies that are outside of your line of sight. This is very important for indirect fire weapons such as long range missiles. This sharing can be blocked by an enemy ECM in close proximity.
After an enemy has been targeted, your 'Mech will begin to gather information about about their current status. This process takes several seconds depending on your distance to the enemy 'Mech and can be sped up through the use of various equipment, quirks and skill tree nodes. Once the target information has been gathered a paper doll will appear in the top right of your HUD showing their current health status and equipped weapons. This is critical information allowing you to see where the enemy is weak and what weapons you need to watch out for while fighting them.
Weapons are listed in mounted order: CT, RT, LT, LA, RA, H - there are no leg mounted weapons in MWO.
Target decay is the amount of time it takes for you to lose a sensor contact after losing line of sight on the target. This allows you to continue to track an enemy 'Mech for a few seconds after they have returned to cover. This is an important stat for indirect fire weapons like LRMs as it may allow them enough time to maintain their lock on for a successful hit. You can boost your target decay in the skill tree but your enemy also has an option to defend against this. Radar deprivation is a skill tree node that reduces the enemy target decay time, allowing you to disappear from sensors earlier. At maximum level radar deprivation reduces this time by 100%, meaning the enemy will lose lock the instant you break line of sight. If you have radar deprivation you will hear a 'chirp' and see your cockpit flash when an enemy 'Mech loses sensor contact with you.
Seismic sensor is another node in the sensor tree that allows your 'Mech to detect enemy movement within a radius. Every two seconds it picks up the seismic vibrations of the enemy 'Mechs as they move across the ground. In order to pick up these vibrations your 'Mech needs to be stationary, however you can still move your torso and arms while standing still and retain the active seismic sensor. Any enemies detected will show up as flashing red dots on your mini map. Important to note that seismic sensor does not relay any vertical information, thus a seismic contact may be above or below you.
The HUD targeting reticle will change color when you do damage to a 'Mech. This can be used to determine if you dealt damage to targets out of view (indirect missiles or a strike consumable).
Electronic Counter Measures (ECM)
ECM is a specialized electronic package that cloaks your 'Mech and allies within a radius from enemy sensors. It reduces the range at which enemy sensors will detect your 'Mech by a percentage, while base value of this reduction is relatively low it can be increased through the skill tree.
ECM has two different settings, disrupt and counter. Disrupt is the standard sensor cloaking while counter is capable of stopping the effects of an enemy ECM within a radius around the countering 'Mech.
Stealth armor is an armor upgrade only for Inner Sphere 'Mechs that is capable of completely removing your sensor profile. Enemy 'Mechs will not be able to target you as long as stealth armor is active. Only 'Mechs that carry ECM are allowed to equip stealth armor. If using Stealth Armor, turning ECM to counter also disables stealth. 'Mechs with active stealth are still detectable by seismic sensor.
The active probe (called "Beagle Active Probe" (BAP) by the Inner Sphere) is an enhanced sensor suite that improves several aspects of your 'Mech's sensors.
- Able to counter the effects of 1 ECM within its radius
- Increases sensor range by 25%
- Increases information gathering rate by 25%
- Allows detection of shutdown 'Mechs within 120 meters for IS and 150 meters for Clan
The Clan-only light active probe has similar but weaker effects for half the weight
- Increases sensor range by 15%
- Increases information gathering rate by 15%
- Allows detection of shutdown 'Mechs within 90 meters
If both an active probe and ECM is equipped, the anti-ECM capabilities of the active probe is disabled.
Targeting computers give small information warfare boosts along with other bonuses. The larger the targeting computer (slots and weight) the greater the bonus.
- Increases sensor range and visual zoom by a percentage
- Increases information gathering rate by a percentage
- Reduces weapon lock-on time by a percentage
- Increases weapon range and velocity
- Increases weapon critical hit chance (except for LBX)
Unmanned Arial Vehicle (UAV)
A consumable that deploys a UAV above your 'Mech that targets enemies within a set radius and duration which can be improved through the skill tree. This provides basic sensor contacts to any 'Mech within the UAVs radius that allows missile lock-on. However this does not allow information gathering therefore you will not be able to see the enemy's current status.
Target Acquisition Gear (TAG)
TAG is a beam style energy weapon that 'paints' a target with a targeting laser. TAG'ing a 'Mech within an ECM field allows targeting of even the ECM carrying 'Mech. Indirect targets painted by TAG are treated as if they are in direct LOS for the purposes weapon lock-on time and missile spread. TAG provides no lock-on or spread benefit for direct line of sight (LOS) targets. See below for more information on LOS.
NARC is a missile system that fires sensor beacons. If the beacon hits a 'Mech it will attach and emit a signal for several seconds. This allows sensor targeting and lock-on even if the enemy is not in line of sight of any allied 'Mech. NARC'ed targets are treated as if they are in direct LOS for the purpose of weapon missile spread; NARCs do not provide weapon lock-on bonuses. See below for more information on LOS.
If you have been NARC'ed you can run for safety with an allied ECM 'Mech; if you are within their cloaking bubble the NARC beacon will be unable to transmit. However this does not remove the NARC so leaving the ECM bubble before the NARC duration is up will cause it to resume broadcasting. A NARC beacon that hits a 'Mech with ECM will disable ECM on that 'Mech for its duration.
Several missile weapons are capable of locking onto and tracking their targets through a sensor lock. You lock onto a 'Mech by placing your arm aiming reticle over their sensor bracket for two seconds (equipping a Targeting Computer can reduce this time). Target lock starts to degrade if your reticle leaves the sensor bracket for two seconds, during which time you can continue to fire. After degrading for two seconds lock is lost. Target lock is immediately lost if your reticle moves more than 25 degrees from the target.
The time to lock-on a target depends on the range and line of sight (LOS):
- Time to lock-on to targets in direct LOS is the fastest - there is no addition time due to range, altho the target must be within your sensor range.
- Indirect LOS lock-on time depends on the range to the target relative to the firing 'Mechs sensor range
- Enemy ECM increases the lock-on time for indirect LOS, but not for direct LOS
There are two styles of missile tracking: 'Holding the lock' and 'Fire and forget':
- ATMs and LRMs are 'holding the lock' style and require you to hold the lock continuously while the missiles are flying towards their target. If lock is lost the missiles will stop tracking and fly straight along their last trajectory; however if lock is regained and the missiles are still in the air they will try to continue tracking the target.
- SSRMs are of the 'fire and forget' style and do not require you to hold the lock while the missiles are flying. You simply need to have a lock at the time of firing and the missiles will continue towards their target no matter what.
ATMs and LRMs may be dumb-fired - fired in the direction of the torso or arm aim reticle (depending where the missiles are equipped) without any lock. SSRMs can only fire if there is missile lock.
Tracking strength is a rating of how well a missile will track a moving target, it can be increased through the use of various equipment and upgrades
Artemis is an upgrade to LRMs and SRMs by reducing missile spread by 30% at the cost of increased weapon size and tonnage and increased ammunition cost; it does not impact SSRMs nor ATMs (the Artemis upgrade is already "baked into" ATMs). However these benefits are only active if you have line of sight of the locked on target at the time of missile fire. Firing indirectly provides none of these benefits and will perform exactly the same as if they were not upgraded.
The Artemis bonus stacks with the bonuses of TAG and NARC. Artemis benefits are removed if the Artemis equipped 'Mech is within an enemy ECM bubble.
Several 'Mechs have unique information warfare quirks such as the Cyclops that gives allies within a radius an increase in sensor range or the Raven-3L that has an increase in NARC beacon duration.