Research:NPC AI Behaviour

Combat Behaviour

NPC Awareness Check

Actions affected	NPC AI
Description
Implementation status	implemented
Analysis status	Verified

This check runs every 5 seconds for each NPC. It occurs whether you are sneaking or not, but isn't the same as the combat distance check.

Player side

if sneaking:
    sneakTerm = fSneakSkillMult * sneak + 0.2 * agility + 0.1 * luck + bootWeight * fSneakBootMult
else:
    sneakTerm = 0

fatigueTerm = fFatigueBase - fFatigueMult*(1 - normalisedFatigue)
where normalisedFatigue is a function of fatigue. empty fatigue bar -> 0.0, full fatigue bar -> 1.0
 
distTerm = fSneakDistanceBase + fSneakDistanceMultiplier*dist
x = sneakTerm * distTerm * fatigueTerm + chameleon (+ 100 if invisible)

NPC side

npcTerm = npcSneak + 0.2 * npcAgility + 0.1 * npcLuck - npcBlind
npcFatigueTerm = fFatigueBase - fFatigueMult * (1 - normalisedFatigue)
 
using NPC normalisedFatigue

if PC is behind NPC (180 degrees):
    y = npcTerm * npcFatigueTerm * fSneakNoViewMult
else:
    y = npcTerm * npcFatigueTerm * fSneakViewMult

Final check

target = x - y
roll 100, win if roll < target

Comments

Appears straightforward and bug-free. NPCs can take up to five seconds to notice you even if you are not sneaking. This function precedes the combat distance check. I have not identified if there is a line of sight check occuring before or after.

According to this formula, NPCs can still detect you when invisible? That seems wrong. Scrawl (talk) 00:25, 7 January 2014 (CET)

AI Tendencies

Fight

Affected by calm and frenzy spells.

Flee

Affected by rally and demoralize spells.