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This is a script-free total recalibration of Skyrim's detection formula, which improves the balanced and realism of sneaking. Enemies will have enhanced sight and hearing abilities, and will search longer when alerted. This mod represents over 300 hours of meticulous research and optimization work.

Permissions and credits
TL;DR: download the "Lite" version to enjoy the best detection mod for Skyrim.

Featured in: Bethesda.net featured mods of May 2017


This is a complete recalibration of Skyrim's detection formula, which improves the balanced and realism of sneaking. It is not a "hardcore" mod - sneaking is both harder and easier where necessary. You can use it by itself, or in combination with perk and gameplay overhaul mods.

This mod greatly improves upon the community's other efforts to mod Skyrim's detection mechanics. Instead of making simple tweaks to the vanilla settings (like all other detection mods do), I have holistically re-calibrated the whole formula from the ground up. This represents over 300 hours of meticulous research and optimization work.


  • No scripts. No perk edits. No performance impact. 100% reliable.
  • NPC view cone is reduced to 160deg (from 190deg in vanilla).
  • Ambient light, equipment weight, and line-of-sight are now more important than your sneak skill level. Enemies won't become deaf and blind as you increase your sneak level and perks.
  • NPCs are much more sensitive to light. They can now see better in dimly lit environments, and will quickly spot you if you are carrying a light source. Even equipping a spell that lights up your hand will get you spotted. However, in total darkness NPCs are just as blind as in vanilla, and sometimes even more so.
  • A higher attenuation factor in the detection formula enables NPCs to see you realistically in very low light levels when very near, without making detection over-powered at further distances (same applies to hearing). It also makes this mod scale better to different perk, armor, and lighting mods.
  • NPC sight and hearing range is now the same inside and outside (in vanilla, enemies only had half the detection range inside compared to outside). This means interior detection range is now doubled compared to vanilla, while exterior detection range is only slightly higher than in vanilla.
  • Enemies will search longer - 70 seconds if you fire an arrow into their knee (was 20), ~70 sec after losing track of someone in combat (was ~40), 40 sec if they find a dead body (was 15), and 20-50 sec if they see or hear something (was 12-20).
  • When searching, enemies will do a better job checking corners, and they will cover a larger area.
  • The huge difference between standing and sneaking has been reduced to a realistic amount. No longer will enemies detect you unfairly far away just because you were standing, and neither will they become blind and deaf the moment you start to sneak.
  • NPC wall-hacking has been reduced in various scenarios: In vanilla, if you broke line-of-sight in combat, NPCs could wall-hack you for up to 10 seconds - this has now been reduced to 5 seconds (making it easier to evade a pursuing enemy, and then backstab them). In vanilla, any nearby enemy with a sneak skill over 50 would wall-hack you indefinitely if you were standing - this effect has now been reduced. In vanilla, casting any loud spell would heavily drain your ability to stay hidden for 5 seconds, which usually resulted in getting wall-hacked over large distances for 10 seconds - this has now been reduced to a slight drain for only 2 seconds, which almost eliminates wall-hacking.
  • "Invisibility" and "Muffle" effects now work when standing and running. In vanilla, these were often ineffective when out of sneak mode.
  • When an enemy becomes alert and starts to search for you, they get a small boost to their detection ability (to simulate concentration).
  • If an enemy has not detected you yet and is in combat with someone else, it is now easier to sneak past or backstab them (since all their attention is focused on combat). This effect is stronger in dark environments.
  • NPC reaction time is slightly increased in some situations. If you suddenly appear in front of a relaxed enemy, they may need a second to realise you are an enemy (instead of instantly attacking as they do in vanilla).
  • Sleeping enemies have slightly reduced hearing abilities (in vanilla their hearing was the same as when awake).
  • Enemies will notice dead bodies 10m away and start a search (was 5m in vanilla). Civilians are also more likely to react to dead bodies nearby instead of ignoring them as they often do in vanilla.
  • When someone sees you commit a crime, the distance guards come running has been reduced moderately.

5 versions for different user preferences and various lighting mod setups

You can only use one version at the same time.
You can use any RAID version with any lighting/weather mod setup you want, but some recommendations are provided here.

Realistic AI Detection Lite
Small increase to NPC visual detection ability both indoors and outdoors. Small audio detection rebalance.
This is what vanilla detection should have been. This version is suitable for all setups if you want a bit more realism but not much more difficulty.
If you are not sure what version to get, start with this one, and upgrade to a more powerful version later if needed.
Optimal for "Climates of Tamriel", "Vivid Weathers", and most ENBs.

Realistic AI Detection - Medium Interior, Medium Exterior
Medium increase to NPC visual detection ability both indoors and outdoors. Moderate audio detection rebalance.
This version is suitable for vanilla lighting and many other lighting/weather mods if you want much more realistic and challenging detection gameplay.
Also ideal for ELFX and RLO when either is used at vanilla brightness levels (not using their darker lighting options).

Realistic AI Detection - High Interior, High Exterior
Large increase to NPC visual detection ability both indoors and outdoors. Moderate audio detection rebalance.
This version is only suitable for a few lighting mods that have a crippling effect on detection. It is over-powered for Vanilla and most other lighting/weather mods.
This version is ideal for ELFX when using it's "Enhancer" and "Weathers" module.
Also optimal for RLO 4.1 (if using it's darker dungeons and weathers module).

Realistic AI Detection - High Interior, Medium Exterior
Large increase to indoor visual detection ability, medium increase to outdoor detection. Moderate audio detection rebalance.
This version is only suitable for a few lighting mods that have a crippling effect on detection. It is over-powered for Vanilla and most other lighting/weather mods.
This version is ideal for ELFX when using it's "Enhancer" but NOT its "Weathers" module.
Also optimal for RLO 4.1 (if using it's darker dungeons, but NOT its weathers module).

Realistic AI Detection - Medium Interior, High Exterior
Medium increase to indoor visual detection ability, large increase to outdoor detection. Moderate audio detection rebalance.
This version is only suitable for a few lighting mods that have a crippling effect on detection. It is over-powered for Vanilla and most other lighting/weather mods.
This version may be optimal for ELFX when using it's "Hardcore" and "Weathers" module.
Also optimal for RLO 4.1 (if using it's weathers, but NOT its dungeons module).

A note about balance
It is virtually impossible to balance NPC detection for some darker lighting or weather mods because they use darkening methods (like heavy imagespace modifiers) that are not taken into account by Skyrim's detection system - so while you see very little, the NPC can still see very well. This includes the darker settings in "Climates of Tamriel" and "Vivid Weathers" (if normal brightness settings are chosen, then these mods are fine). Very dark ENB presets also have this problem, since all ENB effects are ignored by Skyrim's detection system. ENB presets that do not make environments significantly darker should be ok though.

If you want much darker environments while keeping detection properly balanced relative to the amount of light, the best lighting/weather mods are:
"Enhanced Lights and FX" (ELFX) or "Realistic Lighting Overhaul" (RLO), preferably without any contamination from other lighting/weather/ENB mods.

Use your mod management program, or put the .esp file in your Skyrim/data folder and activate it in the mod tab from the main menu.
Place it near the bottom of your load order (the LOOT sorting tool often fails to sort this mod correctly).
Do not clean this mod with SSEEdit.

Just uninstall it using your mod manager, or delete the mod's .esp file in Skyrim/data
It is 100% safe to uninstall or re-install during a serious playthrough.

Compatibility with other mods
This mod is compatible with just about everything, but must be loaded after any mods that also edit detection settings (like Immersive Citizens, Combat Evolved, Thief Skills Rebalance for Ordinator, and possibly NAT). That way it will overwrite any conflicting detection settings while leaving everything else from the other mod perfectly untouched and functional.

Mods that change detection settings via scripts (like Skytweak) may produce unexpected results if used in combination with this mod.
"Improved Traps" is compatible, but RAID will reduce the range enemies can hear traps by about 30-40%.
"Face Light" may cause problems if used with this mod.
And, as explained further up, some darker ENBs and lighting/weather mods may cause detection to become unbalanced.

Q1: I don't know what version of this mod to use (because TL;DR dude!)
A: *facepalm* - Just use the "Lite" version...

Q2: Do I need to use the "High" version if my mods make the game much darker?
A: NO!!! There are exceptions, but no! Some people are saying this on other forum/youtube comments, but its nonsense. If in doubt use "Lite".

Q3: I tried the "Lite" version but it still feels too difficult. Help?
A: Obviously sneaking will be a bit harder with this mod, but you should be fine if you use common sense, and follow the tips listed below:
   1. Make sure your other mods are not messing up detection (like dark ENBs as explained further up).
   2. Make sure you are in sneak mode (crouched) - duh! (you'd be surprised how many people forget this).
   3. Avoid enemy line-of-sight, no matter how high your sneak skill/perk level is.
   4. Don't equip any light source, including spells that light up your hand.
   5. Invest in the "stealth" and "muffled movement" perks.
   6. The invisibility potion or spell will be essential in some situations.
   7. Stay in the shadows, where it is dark. (The ELFX and RLO mods make sneaking easier because they make dungeons darker, the correct way)
   8. Keep the weight of your equipped weapon and armor low (But anything not equipped has no effect on sneaking).
   9. Sometimes it is best to not move, or move slowly (use the walk button on keyboard) when an enemy is near.
  10. Get creative and devise new tactics like this - Using inigo's teleport ability to stealth one-shot a bandit chief

Q4: I want to play a sneaky mage, but enemies keep spotting me when I have a glowing spell in my hands. What can be done about this?
A: There is a mod called "Lights Out" that disables spell glow when equipped in your hand. It has compatibility patches for many magic mods. Also, note that looking slightly down from horizontal strongly increases the effect spell glow has on detection. This is a quirk of how Skyrim's detection works, it has nothing to do with RAID. Looking up by just 5deg from horizontal will minimise how much NPCs can detect spell glow. It sounds silly, but its true!

Q5: Sometimes NPCs are very slow to detect me or other NPCs, even when not sneaking (they may walk right past me). Is it caused by this mod?
A: Possibly, but only to a limited extent. If you are using RAID "lite", it may mean your lighting setup requires a more powerful version of RAID like "medium" or "high". Also note that very mild forms of this problem are simply a side effect of RAID reducing NPC field-of-view and wall-hacking abilities. However, if you have a severe form of this, then you have a different problem not caused by RAID (check load orders, mod conflicts, etc).

Q6: Enemies and/or followers are sometimes unresponsive in my game, as if they are brain dead. Is it caused by this mod?
A: No. Check your other mods. Some people even experience this problem in vanilla Skyrim. Also, if your setup has script lag or generally poor performance, detection responsiveness may suffer as a result.
Also note, the "Immersive Citizens" mod will stop civilians and named NPCs from retaliating when you attack, if you are a much higher level than them (they are not brain dead, but controlled by an "avoid combat" AI package).

Q7: Does this mod affect NPCs, mod added NPCs, followers, animals, dragons, falmer etc? Does it affect how NPCs can detect other NPCs?
A: Yes. It affects the detection of everything. This is the case with all detection mods, not just mine.

Q8: Falmer can see me if I use this mod. Aren't Falmer supposed to be blind?
A: Falmer are NOT 100% blind. They are actually 80% blind. In vanilla this may seem like 100% because normal NPC vision is already very weak. In RAID, all enemies can see much better, including Falmer, but their sight is still 80% worse than that of a normal enemy.

Q9: Does this mod work in the old non-Special Edition Skyrim? Does it work in Enderal?
A: Yes, but not the files on this nexus page, there is a nexus page here for the old Skyrim. There are no detection changes between these versions.

Technical information
This mod edits 45 game settings (GMST), and deliberately includes an additional 13 ITM edits (aka dirty edits). The ITMs are safe and ensure this mod functions correctly when loaded after a mod that also edits detection GMSTs.
If you want to know more about what these GMSTs do, download the "GMST Datasheet" on the download page.

(format: GMST name, vanilla value, RAID2 medium/medium value)

formula core
fSneakBaseValue                                                  -15   -4.0
fSneakDistanceAttenuationExponent                        2    5
fDetectionViewCone                                             190    160
fDetectionSneakLightMod                                      15    8.5
fSneakLightMult                                                 0.33    0.6
fSneakLightExteriorMult                                       0.5    1.0
fSneakLightMoveMult                                         0.01    0.02
fSneakLightRunMult                                             0.2    0.7
iLightLevelInteriorMod                                          25    13
iLightLevelExteriorMod                                           0    8
iLightLevelMax                                                   300    200
fSneakSoundsMult                                                   1   .64
fSneakSoundLosMult                                            0.3    0.28
fSneakEquippedWeightBase                                   12    3
fSneakEquippedWeightMult                                    .5    0.3
fSneakActionMult                                                    2    1
fSneakRunningMult                                                 2    2.5
fSneakMaxDistance                                            2500    6500
fSneakExteriorDistanceMult                                  2.1    1.0
fDetectProjectileDistanceNPC                               512    ITM
fDetectProjectileDistancePlayer                          1024    ITM
fDetectEventDistanceNPC                                    512    ITM
fDetectEventDistancePlayer                                1536    ITM
iCrimeAlarmLowRecDistance                              2000    1500
iCrimeAlarmRecDistance                                    4000    3000
fDeadReactionDistance                                        400    800
fCombatStealthPointRegenAlertWaitTime               10    15
fCombatStealthPointRegenDetectedEventWaitTime 10    30
fCombatStealthPointRegenAttackedWaitTime         15    50
fCombatStealthPointRegenLostWaitTime                10    20
fCombatDetectionLostTimeLimit                            10   15
fCombatDetectionNoticedTimeLimit                       10    5
fActorAlertSoundTimer                                            5    2
fDetectionEventExpireTime                                     5    2
contextual modifiers
fSneakAlertMod                                                     0    1
fSneakCombatMod                                             -0.4    -2
fSneakSleepBonus                                                  0    -0.3
skill system
fSneakSkillMult                                                   0.5    0.07
fPlayerDetectionSneakMult                                  0.4    0.8
fPlayerDetectionSneakBase                                   10    5
fSneakPerceptionSkillMax                                    100    ITM
fSneakPerceptionSkillMin                                        0    ITM
stealth point system
fCombatStealthPointDrainMult                                3    ITM
fCombatStealthPointRegenMult                            0.2    0.08
fCombatStealthPointRegenMin                               5    2.5
iCombatStealthPointDetectionThreshold                25    50
iCombatStealthPointSneakDetectionThreshold        70    ITM
fCombatStealthPointAttackedMaxValue                  50    ITM
fCombatStealthPointDetectedEventMaxValue          75    ITM
fCombatStealthPointMax                                     100    ITM
search system
fCombatSearchExteriorRadiusMax                     2048    2560
fCombatSearchExteriorRadiusMin                     1280    1536
fCombatSearchInteriorRadiusMax                     1280    1536
fCombatSearchInteriorRadiusMin                        768    1024
fCombatSearchSightRadius                               1536    1024
fCombatSearchInvestigateTime                           2.5    4
fCombatSearchLookTime                                       1    ITM
fCombatSearchStartWaitTime                                1    ITM

Mod by Olivier Doorenbos.
You may distribute this mod in a "mod pack", as long as it is non-commercial, you mention my name, and provide a link back to this page.
If you want to do anything else that goes beyond personal use, please contact me first (here on Nexus).
And hey Bethesda Studios, I would be happy to properly calibrate the detection formula of your next Elder Scrolls game. You could do with my help!

Not suitable for casual gamers and console peasants. No liability will be accepted if these risk groups experience severe stress and feelings of inadequacy as a result of using this mod.
Approved for the glorious PCMR.

(Off Topic):

List of Rated Quest/Dungeon Mods:
Here's a list of Skyrim quest mods I have played, and rated, as objectively as possible (just my opinion).
I hope this helps you find some good quest mods you may not have tried before (and I hope it helps you avoid wasting time on the bad ones).

Note: this is based on my longer Non-Special Edition list, but only includes the mods that have been ported to Skyrim Special Edition.
Note: well known mods in bold
Note: "#" indicates a mod unsuitable for a non-dragonborn player character
Mod Name                     Rating    Size      Stability/bugs  Combat       Notes 
mediEvil H.o.G.             10/10    fair         excellent      medium+     excellent custom music and annimations. great humor. epic final boss fight
beyond skyrim: bruma   9/10     HUGE      good             medium+    on par with official DLC like dawnguard/dragonborn. extremely lore-friendly
interesting NPCs            9/10     HUGE      mediocre      medium+     excellent quests, followers, writing, and humor. very lore friendly. some bugs
inigo                              9/10     fair        excellent        -               great follower with very good voicing. also has a good short quest. lore friendly
***DAWNGUARD***          *9/10*    HUGE     good             medium      for comparison, this DLC would get a "9/10" if it was a mod (less as paid DLC)
clockwork                      9/10     large      good             medium+     beautiful mansion. epic dungeon. good quests and voicing. creepy
# wyrmstooth                 7/10     HUGE     mediocre      medium+      beautiful DLC sized island. excellent music and voicing. but some glitchy quests
# dreamborne isles          7/10     large      mediocre      very hard     wonderful environments and music. lots of platforming. but unbalanced combat
the forgotten city           7/10     large      good             medium+     good story with time travel, multiple endings and custom music. minor flaws
the shire                         7/10    HUGE      poor             hard            huge beautiful hobbit land. branching story. but patronising quests/dialog. lvl 30+

# moon and star             7/10     fair        ok                 hard           great voicing, puzzles, village, and custom boss fight. minor quest order flaws
falskaar                         7/10     HUGE      ok                hard            new land with quests and good dungeons. some harsh combat and other flaws
project AHO                    7/10    large       bad              hard           great visuals, music, and voicing. but awkward plot, some fetch quests, and bugs
helgen reborn                7/10     large      ok                hard            good variety, great dungeon, but some "meh" content too, and unconvincing plot
# moonpath to elsweyr   6/10     large       ok                medium      nice jungle environments, decent voicing. but basic quests and feels unfinished
darkend                         6/10     large      good             very hard+   dark souls inspired mod. impressive level design. custom enemies. no quests
                         6/10     fair        poor              medium      good lore, atmosphere and custom music. needs patches. not follower friendly
a feathered friend           6/10     small      good             easy           nice short quest, well voiced
# the hanging gardens     6/10     fair        mediocre       very hard    beautiful dwemer temple/island, but low fps and not follower friendly
conan hyborian age          6/10     small     good             hard           decent dungeon quest, with custom music and voiced conan, hard boss
easyrider dungeon pack   6/10     large      mediocre       medium      a set of high quality dungeons. but minor fps dips and not follower friendly
the haven                       5/10     fair        bad               -                beautiful island (no quests), but low fps, and dirty edits that mess up your game
dwemer colosseum          5/10     fair        mediocre       hard           arena with crowd effects, but has some rough edges...and a flying ship
# insanity clause             5/10    fair        bad               *mixed*       funny xmas themed mod, great voicing, but has very glitchy quest mechanics
shadows of the past        5/10    fair        ok                  hard           moderately decent fetch/kill quests in varied locations, some poor voice acting
mharphin v2                   5/10    fair        poor              very hard    sometimes funny and wonderful. also weird, buggy, and tedious. not lore friendly
jurgholm                        5/10    fair        good              very hard    large dremora dungeon with some neat features. for lvl 60+ players
forgotten dungeons         4/10    large      ok                 medium      a mix of decent and bad dungeons. well balanced difficulty
#anna npcs                     4/10    large      mediocre       -                 like "interesting NPCs", but lower quality and less lore friendly. a few good bits
solemn Keep                   4/10    small      DANGER         hard            nice looking bandit dungeon, but may cause severe script lag* (tested on Oldrim)
immersive dungeons       4/10    large      bad               very hard+   huge dungeons with many enemies and too many traps. no followers. some CTDs
skyrim sewers                3/10    fair        mediocre       medium       dull level design. very under-scaled relative to overworld distances
#gray cowl of nocturnal 3/10    large      good              hard+         tedious puzzles, running, backtracking, bad level design, and bad writing. OP loot