About this mod
Changes to multiple aspects of the AI behavior for a more realistic gameplay experience
- Requirements
- Permissions and credits
This mod applies many changes concerning how NPCs & creatures behave in the game on various circumstances. Greatest focus placed upon enemy combat patterns and detection system.
It is the result of a lot of tweaking, reading and testing in game. Also by having some experience with some modifications I did back in the day for Fallout 3.
- Generic AI detection tweaks
- Effect of lighting conditions is now much more important. It will be the most critical factor on detection chance
- Adjusted the impact that sound and noises have on detection
- NPC status (eg. just woke up, sitting etc) now affects its alertness
- Player sneak skills now pose a smaller coefficient on successful stealth. Environmental conditions (ie. lighting / darkness) are more important now
- Detection distance tweaked
- Changes in various timers, eg. how long enemies will look / be alert, or search for you (increased all the more)
- Stealth point system tweaks
- AI visibility fov slightly reduced, from 190 to 170. I believe it was way too much
- Patrolling / Sandboxing areas are expanded
- Adjusted some combat tactics, such as how often AI should throw grenades or advance their cover etc.
Install with NMM / MO,
or manually
by extracting the downloadable archive contents and pasting the data folder into the main game folder: ~/Steam/Steamapps/Common/Fallout 4
The mod works with, or without any of the DLC. It is compatible with most mods, but make sure to load it as low in the load order as possible (loaded last / higher priority) to make sure all changes are applied. It is a very safe and stable modification.
This mod consists solely of game-setting changes. As such it can be installed, or uninstalled at any time without side effects.
The following variables have been changed (presented in categories) vanilla -> mod
Detection formula variables:
- fSneakVisualBaseValue -20 -> -5
- fSneakDistanceAttenuationExponent 2 -> 4
Visibility & Lighting factor contribution in Detection:
- fDetectionViewCone 190 -> 170
- fDetectionSneakLightMod 15 -> 8
- fSneakLightMult 0.33 -> 0.73
- fSneakLightExteriorMult 0.5 -> 1.0
- fSneakLightRunMult 0.4 -> 0.8
- iLightLevelInteriorMod 25 -> 10
- iLightLevelExteriorMod 0 -> 4
- iLightLevelMax 150 -> 200
NPC condition modifiers:
- fSneakAlertMod 0 -> 0.5
- fSneakCombatMod -0.4 -> -2 // NPC is less likely to detect/bother with you if he's already fighting)
- fSneakSleepBonus 0 -> -0.2 // NPC takes some time after waking up to realize the enemy)
Player Skill factor in detection:
- fSneakSkillMult 0.5 -> 0.25
- fPlayerDetectionSkillMult 0.4 -> 0.3
- fPlayerDetectionSneakMult 0.4 -> 0.8
- fPlayerDetectionSneakBase 10 -> 5
- fSneakPerceptionSkillMax 90 //sight depth is determined by perception
AI Distance factors:
Basically detection can happen from greater distances
- fSneakMaxDistance 4096 -> 6144
- fDetectProjectileDistanceNPC 256 -> 512
- fDetectProjectileDistancePlayer 512 -> 1024
- fDetectEventDistanceNPC 512 -> 1024
- fDetectEventDistancePlayer 2048 -> 3072
- fDeadReactionDistance 400 -> 1000
AI Search system:
Much increased radius of AI in searching / be alert for enemies - Very needed
- fCombatSearchExteriorRadiusMax 3072 -> 4096
- fCombatSearchExteriorRadiusMin 1536 -> 2048
- fCombatSearchInteriorRadiusMax 1536 -> 2048
- fCombatSearchInteriorRadiusMin 768 -> 1280
- fCombatSearchLookTime 1 -> 3
- fCombatSearchStartAttackLocationTimeLimit 10 -> 20
- fCombatSearchStartKnownLocationTimeLimit 30 -> 40
- fCombatSearchInvestigateTime 2.5 -> 10
Timers:
Enemies will be alert, suspect and hunt you for a longer time
- fCombatDetectionLostTimeLimit 10 -> 40
- fCombatDetectionKnownTimeLimit 10 -> 30
- fCombatDetectionSuspectedAttackTimeLimit 15 -> 30
- fCombatDetectionSuspectedKnownTimeLimit 5 -> 20
- fCombatDetectionDialogueMinElapsedTime 1 -> 4
- fCombatDetectionDialogueMaxElapsedTime 3 -> 12
- fDetectionEventExpireTime 2.5 -> 10
Stealth Point System & Detection:
Mostly increasing duration of stealth related attributes.
- fCombatStealthPointRegenAlertDelayTime 10 -> 20
- fCombatStealthPointRegenDetectedEventDelayTime 12.5 -> 25
- fCombatStealthPointRegenAttackedDelayTime 20 -> 40
- fCombatStealthPointRegenLostDelayTime 1 -> 4
- fCombatStealthPointMax 100 -> 200
- fCombatStealthPointKilledMaxValue 50 -> 75
Expanded sandboxing / patrolling (a floor's height is 288 game units - AI is able to wander around floors of a building - up to 4 from original floor):
- fSandboxCylinderBottom -100 -> -576
- fSandboxCylinderTop 150 -> 576
AI Combat Tactics:
AI becomes more energetic and tactical during combat
- fCombatCoverAdvanceChanceMin 0.1 -> 0.25 // cover system tweaks
- fCombatCoverAdvanceChanceMid 0.5 -> 0.6
- fCombatCoverAdvanceChanceMax 0.75 -> 0.9
- fCombatCoverChangePositionChance 0.25 -> 0.35
- fCombatRangedThrowDelay 5 -> 7.5
- fCombatRangedGrenadeThrowDelay 7.5 -> 12.5 // can't spam grenades all the time
Audio conditions affecting detection (including gear weight etc):
- fSneakActionMult 1 // affects noise level of weapons, how much it affects detection
- fSneakSoundsMult 1 -> 0.8 // audio is slightly less significant in sneaking except when running (see fSneakRunningMult) - eg. the player is careful not to make noise for trivial equip/unequip matters
- fSneakEquippedWeightBase 12 -> 6
- fSneakEquippedWeightMult 0.5 -> 0.25
- fSneakRunningMult 2 -> 4 // running when in stealth conditions makes it easier for ai to hear you (the enemy to spot you), because you are making more noise
Note: I've left a couple of variables unchanged (no arrow ->), as "still open for experimentation".
v1.1 Released! (12/1/2018)
Features:
Detection & sneak tweaks. Some bugs fixed. Numerous Combat Style changes make for a more punishing AI.
- fDetectionViewCone 170 -> 190 // revert to original value
- fCombatCoverAdvanceChanceMin 0.25 -> 0.2
- fCombatCoverChangePositionChance 0.35 -> 0.2
- fCombatRangedThrowDelay 7.5 -> 15
- fCombatRangedGrenadeThrowDelay 12.5 -> 22.5
- iLightLevelExteriorMod 4 -> -12 // the higher the harder to be detected
- iLightLevelInteriorMod 10 -> -4 // same here
- fSneakActionMult 1 -> 3
- fCombatSearchLookTime 3 -> 4
- fDeadReactionDistance 800 -> 1200
- fSneakSleepBonus -0.2 -> 0 // revert to original value
- fCombatStealthPointMax 200 -> 100 // revert to original value
- fCombatThreatViewCone 120 -> 150
- fSneakExteriorDistanceMult 1.25 -> 2
- fSneakDistanceAttenuationExponent 2 -> 4
Note: When updating it's best to wait some in game hours and restart your current cell status (leave and come back again, or go to an interior location and wait some hours).
v1.2 Released! (9, June, 2021)
Slight decrease of the difficulty incurred by the mod, due to popular request.
Changes:
AI Search system:
A more realistic timescale (set timescale to 4 / 5 / 6) is mandatory (imo)
Pick a better FOV 90-105 for 1st person, 75 for 3d person to be able to see and respond better to what's around you.
In addition the following gameplay mods:
- Piles of Corpses - Increased De-spawn timer
- Longer Area Respawn : must use those 2 along with a more realistic timescale mod
- Global Damage Multipliers for all Difficulties : For increased damage output and faster, more tactical and thoughtful battles - recommended
- Fire, Grenades, Explosions Enhanced
- No Sneak HUD Indicator : Remove sneaking messages for immersion
- Carry More with Power Armor : +200 for me
- Stronger Robots, Synths & Turrets , Deadly Deathclaws : make all robots, turrets & Deathclaws powerful as they should be
What I wanted to establish in this mod, is for the player to spend less time thinking how the game actors would respond to my actions. For example in real life you know that when you stand 30 meters away from someone at line of sight he will see you. In the game that's not the case. He may, or he may not, you must make guesses if you haven't been playing for dozens of hours to get the enemy patterns down.
In real life if you (were to) break into someone's house at night will you start lighting candles in order to see more clearly and navigate through the house? Will you start moving faster just to get on with your daily (/nightly) business? The game doesn't care very much about that. Same goes for absolute darkness - if you are spotted.
My goal was realism, meaning greater difficulty but also greater sense of achievement. Realism means we should spend less time thinking how a "game" would respond in a specific scenario. For example when infiltrating a raider base/camp. I would just have to act how I would in real life, ie. be absolutely surreptitious and silent. Which means any noise, running, line of sight with enemy will get you spotted. You will have to be extra careful. If you are spotted, you will no longer be able to flee and after a few seconds the enemies searched around the place! Emphasizing this, the enemy AI will be relentless in their search patterns. The enemy doesn't have schizophrenia. He knows what he saw, he knows what he heard. He saw you! It's a matter of life and death for him in the apocalypse. No longer will will an enemy NPC stop searching for you after a few seconds and only in a minor area you were last sighted! [There is ~4 times more searching time actually and x1.5 greater distance radius. The game separates searching time in "look" time - CAUTION -, as just looking or being suspicious, and in time after you have already been spotted - DANGER - (in which case searching time is much lengthier than "look" time).]
So do you understand? You don't have to think how the enemies / game ai would react, you act more based on real life intuition (that you already possess hopefully).
All these factors and much more (see technical section) can be adjusted by properly setting various formula coefficients that affect the gameplay. Bethesda set them loosely, because the average gamer doesn't notice and thus may not care about that sort of thing. This mod makes these coefficients more harsh by performing the delicate and intricate process of optimization.
But make sure you also have (at the very least) a greater damage mod in order for all of this to make sense. Even if you the perfect ai mod, what does it matter if the enemies can't kill you due to complete imbalance? No tactical skills and no challenge and no reward.
# Contact
website: www.keyc0de.com
Of course Bethesda for Fallout is always the first to give thanks for creating the game!
The websites below helped a great deal in assembling key information:
- Skyrim Realistic AI Detection - Olivier Doorenbos's mod for Skyrim helped me a great deal - packed with information about the game settings. He basically conducted a similar optimization procedure for Skyrim.
- Older GECK site with many formulas and explanations
- Fallout 4 wikia pages
- The Creation Kit pages, particularly the Detection section which contains many formulas with explanations, as well as the Game settings section which contains many game settings with explanation about their function