Category:Detection

Detection is Oblivion's stealth mechanic. The concept isn't complicated: every actor has a degree of awareness of every other nearby actor, called a detection level. If this detection level is above a certain threshold then the searching actor (the "detector") is fully aware of the hiding actor (the "target"). The detector can then attack, offer a greeting, report the target's crimes, etc. If the detection level falls below the threshold again, the detector "loses" the target and can no longer interact with it.

Quite a few variables go into calculating detection levels. They fall into three basic categories: Sight, Sound, and Sneak Skill. Sight describes how well the detector can see the target, and only matter if the detector actually has a direct line-of-sight. Sound measures how much noise the target is making from movement and from being in combat. Skill measures the sneak skills of the detector and the target. In all three categories the distance from the detector to target plays a very important role.

Some of the conditions in the formula are still under investigation. In particular, the detection does not always correctly recognize when the target is in combat. Whether this is specific to the player or due to some other bug is not yet known.

The complete formula for Detection Level is given below. Because the formula is so complicated, it is broken into smaller pieces and organized in a table. Conditional terms are enclosed in square brackets, e.g. "[ + 400, if target is yellow]" means "add 400 if the target is yellow, otherwise ignore this term".

Detection Level Formula

0

-100

fSneakBaseValue 
[ + fSneakTargetAttackBonus, for a single frame the first time the target attacks the detector]
[ + SoundBonus, if target is not swimming]
[ + fSneakSleepBonus, if detector is sleeping]
[ + SightBonus, if detector is awake and has line-of-sight to target]
+ SkillBonus

fSneakSoundsMult * DistanceFactor *
(
  [ MovementFactor, if target is moving and target Sneak mastery < Expert]
  [ + fSneakTargetInCombatBonus, if target is in combat]
)
[ * fSneakSoundLosMult, if detector has no line of sight to target]

(
  fSneakBootWeightBase
  [ + (fSneakBootWeightMult * (tgt boot weight)), if tgt Sneak mastery < Journeyman ]
)
[ * fSneakRunningMult, if target is running ]

fSneakLightMult * DistanceFactor * LightFactor * ChameleonFactor * BlindnessFactor
[ * fSneakSwimmingLightMult, if target is swimming]  

fDetectionSneakLightMod + 
(
  (light level on target) 
  [ * fDetectionNightEyeBonus, if detector has Night Eye]
)

1 - (Chameleon level of target)/100

1 - (Blindness level of detector)/100

fSneakSkillMult * 
(
  (detector Sneak skill * DistanceFactor)
  [ - target Sneak skill, if target is sneaking and not in combat]
)

1 - (distance between detector and target) / MaxDetectionRange

fSneakMaxDistance 
[ * fSneakExteriorDistanceMult, if in exterior cell]

Detection Thresholds

If the Detection Level is greater than a certain threshold, the detector can becomes aware of the target. The thresholds are:

A final note: The target-is-in-combat bonus is fairly significant. Combined with the much lower combat threshold, this can make it very difficult for an actor to return to hiding once a hostile actor has seen them.

Note

• Dead actors seem to have their detection status "locked in" at whatever value it was when they died. This means an actor aware of the player when the player kills him, will always be considered aware of the player (though this does not matter since the actor is dead). It is therefore important in scripts which check detection levels to also make sure that the "detector" is, in fact, alive, in addition to checking other detection settings.

See Also

Sneak