Fight:
The NPC becomes aggressive and defensive, triggered by threats, when cornered or insulted.
Flight: When the NPC tries to escape or avoid, this happens when there are overwhelming odds and loud noises like gunshots, explosions, screaming.
Freeze: The NPC just, freezes, then become immobile, silent, from sudden danger, a traumatic experience like exposure to open flesh wounds, blood, physical trauma.
Customization Ideas:
**Personality profiles:**Some NPC's are naturally more prone to flight, others to fight, based on the NPC experience (Civilian, soldier, ect)
Stress Meter: NPC's build up stress, once a threshold is hit, their response activates.
Enviromental Cues: Loud noises, eerie atmospheres with a lot of exposure to open wounds, ripped flesh, it pushes them to a reactive state.
Gameplay Impact
When the NPC's hit a certain point in the "Stress Meter" they could run, lash out, or freeze.
Players could learn to read the NPC's body language and use it to their advantage (Yes, war crimes)
Adds emotional realism and unpredictability.