AI director
An overseeing system that tunes a game's pacing in real time — enemies, resources, intensity — by how the player is actually doing, rather than by fixed spawn tables.
The name and the idea were popularized by Valve's Left 4 Dead (2008), whose "Director" paced zombie hordes, item placement and music by reading the player's stress — health, position, how recently things got bloody — and deliberately building peaks and lulls. Procedural dramaturgy instead of a script.
Unlike enemy AI, the director steers the whole experience, not a single agent. Variants have since been used for dynamic difficulty and encounter pacing in many games. It sits above the behavior trees and utility AI that drive the individual characters.