Realistic AI Detection (better sneaking) by Olivier Doorenbos
Skyrim » Stealth
Added: 20/03/2016 - 02:52PM
Updated: 29/05/2017 - 09:57PM

767 Endorsements

1.0 Latest version

10,079 Unique D/Ls

19,042 Total D/Ls

69,253 Total Views

Uploaded by OlivierDoorenbos


Last updated at 21:57, 29 May 2017 Uploaded at 14:52, 20 Mar 2016

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

NOTE: compatible with the Enderal total conversion mod, and also available for Skyrim Special Edition here.

QA tested and featured by... featured mods of May 2017


This is a total recalibration of Skyrim's detection formula (no scripts), providing much more realistic and challenging sneaking. Enemies will have enhanced sight and hearing abilities, and will search for you longer when alerted.

This mod greatly improves upon the community's earlier efforts to mod Skyrim's sneak detection mechanics. Instead of making simple tweaks to the vanilla detection parameters (like all other detection mods do), I have completely re-calibrated them from the ground up. This represents over 100 hours of meticulous research and testing work.


  • No scripts. No performance impact. 100% reliable.
  • AI view cone is reduced to 165deg (from 190deg in vanilla).
  • AI sensitivity to light is far higher than in vanilla. They can now see realistically in the dark. Carrying a light source like a torch or candlelight spell will now cause enemies to spot you quickly from large distances. Even equipping a spell that lights up your hand will now get you spotted at shorter distances.
  • AI visual detection range is higher for most conditions, within reason. However, the practical max detection distance in full sunlight is not much higher than in vanilla.
  • The effect distance has on both visual and sound detection is far more balanced and realistic, due to a higher attenuation factor in the detection formula. This enables AI to see you realistically in very low light levels when very near, without making detection over-powered at further distances.
  • The difference standing or crouching makes to visual detection is reduced to a realistic level. No longer will enemies become blind the moment you start to crouch.
  • AI hearing ability is much more consistent - no longer will enemies hear you at unfairly large distances at the beginning of the game, and they won't suddenly go totally deaf as you level up your sneak skill and perks. For example, the "Muffled Movement" perk will still make sneaking much easier, but it will not make all enemies deaf any more.
  • The unrealistic difference between indoor and outdoor sound detection is removed (in vanilla, enemy hearing was better outside than inside, for no logical reason).
  • Enemies will search for you longer - about 30sec if they see you (instead of 10), and about 60sec if you fire an arrow into their knee (instead of 15).
  • When an enemy becomes alert and starts to search for you, they get a small boost to their detection ability (to simulate concentration).
  • Enemies further away from you (and in other rooms) are now better at noticing the noise from open combat and audible spells. They are more likely to pass on the alarm call to allies within shouting distance. This means that sometimes when you alert one enemy, they will alert all their allies within reach in a "chain reaction" causing many NPCs further away to be aware of your presence. Successful stealth kills and the silent spell casting perk are essential to reduce the chance of this from happening.
  • Sleeping enemies have their hearing ability reduced slightly (in vanilla their hearing was the same as when awake).
  • Sneak skill progression is now less important to staying hidden. Skill and perk progression will still make sneaking easier, but more of the challenge will remain for high level characters. Other factors like ambient light and equipment weight are more important now.
  • Enemies that have a very high sneak skill (over about 80) can now "sense" your presence when near, even if you are behind cover and not moving. This mechanic is achieved only through careful adjustments of the detection formula, but is functionally similar to the "detect life" spell, but with shorter range and less precision. It is balanced and lore friendly because it only affects a few NPCs where it would make sense, like falmer and some high level assassin/vampire/mage enemies. It will be as if the falmer can smell you or hear you breathe, the vampire can sense your blood, and the mage is using their magical ability. This mechanic is non-existent in most normal enemies.

5 versions for different user preferences and various lighting mod setups

You can only use one version at the same time.

Realistic AI Detection Lite
Small increase to AI 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.

Realistic AI Detection - Medium Interior, Medium Exterior
Medium increase to AI 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 when NOT using it's "Enhancer", "Hardcore" and "Weathers" modules (as in using ELFX with vanilla brightness).
(This version was renamed from low/low, to avoid confusion with the "Lite" version)

Realistic AI Detection - High Interior, High Exterior
Large increase to AI 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" modules.

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 "Weathers" modules.

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 is ideal for ELFX when using it's "Hardcore" and "Weathers" modules.

A note about balance
It is virtually impossible to balance AI 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 AI can still see very well. This includes the darker settings in "Climates of Tamriel", "Vivid Weathers" and "Purity" (if normal brightness settings are chosen, then these mods are fine). The snowstorms and dense fog in ELFX Weathers are a more mild example. 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.

Put the unzipped file in your Skyrim/data folder and activate it in the launcher, or use the "install from file" function in your mod management program.
(do not clean this mod with Tes5edit)

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 only edits detection settings. There are no perk edits and no scripts. It is compatible with just about everything, and will even work safely with mods that also edit detection (like Ordinator, Requiem, and Stealth Skills Rebalanced etc), as long as my mod is lower in the load order. That way it will overwrite any conflicting detection settings while leaving everything else from the other mod perfectly untouched and functional.

The only mods that may not be compatible are those that use scripts to edit detection settings, like "SkyTweak", "Immersive Detection of NPCs", and "Detection Extended - Hot and Sweaty".
And as explained further up, some darker ENBs and lighting/weather mods may cause detection to become unbalanced.

And regardless of compatibility, there is no reason to use other pure detection mods since my mod renders all of them obsolete. However, this could change if the SDR (Sneaking Detection Recalibrated) mod for Oblivion gets ported to Skyrim. SDR is one of the most advanced detection systems ever implemented in a video game - it uses a dll to replace the game engine's detection formula with a much more advanced one and further augments it with scripts. The author seems to have no plans to port it to Skyrim though, so for now my "Realistic AI Detection" mod is the only serious option.

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 you are not using a different mod that messes 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. Don't equip any light source, including spells that light up your hand.
   4. Invest in the "stealth" and "muffled movement" perks.
   5. Invisibility and muffle effects are more useful now.
   6. Stay in the shadows, where it is dark. (The ELFX and RLO mods make sneaking easier because they make dungeons darker, the correct way)
   7. Keep the weight of your equipped weapon and armor low (But anything not equipped has no effect on sneaking).
   8. Sometimes it is best to not move, or move slowly (use the walk button on keyboard) when an enemy is near.

Q4: I seem to get stuck in combat mode (combat music keeps playing). Help?
A: This is not caused by my mod. If you use the Immersive Citizens mod, it may cause this, as it sets a combat duration timer to 300 seconds. If it is bothering you, I recommend you use the "disengage" cheat power provided within the excellent Death Alternative mod.

Q5: Does it 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.

Q6: Does this mod work in Skyrim Special Edition?
A: Yes, but not the files on this nexus page, there is a new nexus page here for the Special Edition. There are no detection changes to the SE version.

Technical information
Below are the GMST edits in the Medium/Medium version, and the default Skyrim settings for comparison. Some of the settings I use may seem very extreme, but they are all carefully balanced to work well with each other. For more info on what these GMSTs do, read this article.

fSneakSkillMult                   0.1    (was 0.5)
fDetectionViewCone            165    (was 190)
fSneakBaseValue                -4.0    (was -15)
fPlayerDetectionSneakBase  10    (is 10 - deliberate and safe ITM edit)
fSneakDistanceAttenuationExponent    5.0    (was 2.0)
fSneakMaxDistance            6500    (was 2500)
fSneakExteriorDistanceMult    1.0    (was 2.1)
fDetectionSneakLightMod   8.5    (was 15.0)
fSneakLightMult                 0.6    (was 0.33)
fSneakLightExteriorMult     1.0    (was 0.5)
fSneakLightMoveMult         0.02    (was 0.01)
fSneakLightRunMult           0.7    (was 0.2)
fSneakSoundsMult              0.8    (was 1.0)
fSneakSoundLosMult          0.28    (was 0.3)
fSneakEquippedWeightBase    5.0    (was 12.0)
fSneakEquippedWeightMult    0.26    (was 0.5)
fSneakActionMult               1.0    (was 2.0)
fSneakSleepBonus             -0.3    (was 0)
fSneakAlertMod                 1.0    (was 0)
fCombatStealthPointRegenAlertWaitTime        20    (was 10)
fCombatStealthPointRegenDetectedEventWaitTime    30    (was 10)
fCombatStealthPointRegenAttackedWaitTime        60    (was 15 lol)
fCombatStealthPointRegenLostWaitTime        30    (was 10)
iLightLevelInteriorMod        13    (was 25)
iLightLevelExteriorMod        8    (was 0)
iLightLevelMax                   200    (was 300)

Future Plans
This mod is working well and I consider it "finished". However, I am currently working on a large update that will improve detection behaviour in open combat (rather than out of combat which I have already optimized). Once in open combat, Bethesda basically makes enemies wall-hack you - which is unrealistic and feels unfair. Hopefully it will be ready around July-2017, but don't ask for progress updates, it will be released "WHEN ITS DONE"

Mod by Olivier Doorenbos.
If you want to include my mod in one of those huge Russian torrent mod compilations, go ahead, you have my permission.
If you want to include my detection edits in your own mod, please ask for my permission first (and I may be able to help).
If you want to port this mod to another game (like Fallout), that's ok, but I reserve the right to take control of the port in future if I feel like it.

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 all PCMR users.

(Off Topic):

Recommended 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 nice quest mods you may not have tried before. I am very harsh in my ratings, so anything with a 5/10 or higher is "good" and I recommend it.
Mod Name                      Rating    Size     Quality            Notes    
interesting NPCs              9/10     huge     excellent        excellent writing, very lore friendly, huge amount of content, good humor
inigo                               9/10     fair       excellent        short fun quest + great follower
the cheese of ages           8/10     fair       good              very funny but still mostly lore-friendly, good dungeons, custom music, some minor bugs
helgen reborn                   7/10     large    good              good variety and quality, but some "meh" filler content, and predictable plot
sorcery*                           7/10     fair       good             (steam workshop) decent quest, nice environments to explore
undeath                           7/10     fair       good              very lore friendly, good story, custom music, no voice acting though, needs patches
a feathered friend            7/10     small     good             lovely short story, good voice acting
the shroud of jotunheim   6/10     large    *very mixed*   many bugs and tedious parts, but good story and atmosphere, no hand holding, no followers
the hanging gardens         6/10     fair       decent           beautiful dwemer temple/island, but low fps, very hard if under lvl 50, not follower friendly
sea of ghosts*                  6/10     fair       average        (steam workshop) nice ship travel concept, exploration focused, bad voice acting
conan hyborian age          6/10     small     good             decent dungeon quest, with custom music and voiced conan, hard boss
volundr                            6/10     fair       good             decent dungeon, includes slightly OP custom spells and loot
temple of Kruziik             6/10      small    good              nice draugr dungeon, better than heimfeigr (but shorter), cool boss fight
the haven                        6/10     fair      *mixed*          beautiful island (no quests), but low fps, and edits many vanilla assets, causing conflicts

the dead bee scrolls         6/10     small     decent           poor voice acting, but otherwise a good quality small dungeon quest with some dry humor
the mcmiller chronicles     6/10    fair       good               some amusing parts, but also a bit tedious - slow pacing, and very slow voice acting
agent of righteous might  5/10     large    *very mixed*   great story, but many bugs, some very tedious and glitchy quests, mixed writing quality
heimfeigr                        5/10     fair       *mixed*          decent draugr dungeon, custom puzzle and boss, but had some bugs, not follower friendly
ogmund's tomb                5/10     fair       decent            large draugr dungeon, very follower friendly
into the depths                5/10     small     mediocre        basic, but still a nice short haunted dungeon, some jump scares, no followers
lord balmer's playground   5/10     small    *mixed*           short jump scare dungeon with multiple endings, but some tedious and rough edges
the bigger they are*         4/10     small    average          (steam workshop) ok, short, no voice acting
the realms of daedra*      4/10      small    average         (steam workshop) ok, short, no voice acting
pit fighter*                      4/10     fair       decent           (steam workshop) ok, but very repetitive, no difficulty scaling, lacks the thrill of the arena
no mercy*                        4/10    small     average          (steam workshop) meh, poor level design, no voice acting, short, but it is lore friendly
it beats for her                4/10     tiny      average           subtle storytelling, but very basic, no voice acting
lost colony of akavir         3/10    large     *very mixed*    unfinished mod, wonderful huge island to explore, but no quests, and many bugs
rescue bronwen                3/10    small     mediocre        30min of fun, but some bad voice acting, bugs, and stupidly over-leveled enemies

Also check out my 2016 (non-Special Edition) Simple Skyrim Modding Guide - with clear step-by-step instructions.