Hysteresis

Hysteresis is a concept many devs implement intuitively through buffer zones or different thresholds for entering and exiting states. For example, using a wider detection radius to lose aggro than to gain it prevents enemies from rapidly switching states when the player is near the edge of detection.

Hysteresis means a state doesn’t change the instant conditions flip. Instead, it waits until the change is clear. For example:

• Enemy AI state transitions (patrol ↔ chase ↔ search): require clearer criteria to switch back so enemies don’t rapidly oscillate when player skirts edge of detection.
• Joystick deadzone: use different enter/exit thresholds so slight stick drift doesn’t repeatedly flip input state.

Aggro Example

public class Enemy 
{
    public bool hasAggro = false;
    
    public void Update()
    {
        float distance = Vector3.Distance(transform.position, player.position);
        
        // Lost aggro - player escaped
        if (hasAggro && distance > 10f) 
        {
            hasAggro = false;
            return;
        }
        
        // Gained aggro - player too close
        if (!hasAggro && distance < 6f) 
        {
            hasAggro = true;
            return;
        }
        
        // Distance between 6-10: keep current state
    }
}

The magic: Enemy gains aggro at 6 units but only loses it at 10+ units. That 4-unit buffer zone eliminates jittery state switching.