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How the hunter thinks
To watch everything below happen live, run the game with the visualiser
window (nemesis --visualiser), or see the recorded demo and how to read it
in Demos — regenerate it with just demos.
The hunter is built the way Alien: Isolation's xenomorph famously is: two brains. The creature itself only knows what it senses; a director above it always knows where you are, but is only allowed to gesture.
Every tick the hunter checks its senses before anything else:
- Vision is a cone (~110°) with a range that scales with the light on your tile — darkness genuinely hides you, and holding still while sneaking shrinks your profile further. It always spots you at arm's length. Sight lines are grid ray-marches: walls, closed bulkheads and console cabinets block them.
- Hearing is radius-based. Every action carries a loudness in tiles: sneaking ~1.5, walking 4, running 9, crawling through a duct 6, a bulkhead 6, the tracker ping 5, and a generator roaring online 12. Between footsteps you still leak a fraction of your gait's noise, so creeping right past it is never entirely free. Its effective hearing sharpens as the director's aggression rises.
lurk → patrol ⇄ investigate → search → patrol
↘ hunt ↙
- Lurk — dormant in a far vent mouth for the opening moments of a run. Loud noise (or the director's clock) wakes it.
- Patrol — walks room to room, preferring rooms the director has hinted at, pausing to scan.
- Investigate — something was heard: head to the noise, then sweep the area.
- Hunt — you were seen: while the trail is warm it re-paths straight at you twice a second. Lose it and it falls back to your last known position.
- Search — several rounds of checking cells around where it lost you, then back to patrol.
Movement is A* over the walkable grid. Vent cells cost 0.6 of a floor cell — the ducts are its highways, and it moves half again faster inside them — while closed bulkheads cost extra (it has to shoulder them open, a pause and a bang you can hear). Crossing a vent grate creaks, which is exactly the "vent creak at 12 4" trigger the visualiser logs and you may hear nearby.
The director runs above the creature and paces the run:
- Menace is the tension dial: it climbs while the hunter is near (or hunting) and bleeds away when it prowls elsewhere. The ambient audio bed follows it through five bands.
- Nudges: on a clock, the director points a patrolling or searching hunter at the room you are in — never your exact cell. The creature still has to find you with its own senses.
- The leash: a hunter that loiters near an unseen player too long is sent to a far room, so runs never stall with it camped on your hiding spot.
- Escalation: every generator you bring online raises its aggression — sharper hearing, more frequent nudges — and a generator roaring to life always draws it toward the noise. Unlocking your escape route arms your enemy.
Like the xenomorph, the hunter doesn't get faster with time — it gets smarter, unlocking behaviours as it watches you repeat tactics:
- Tracker familiarity. Every ping it hears teaches it what that chirp means. After a few it investigates pings precisely; after enough, a ping heard close by is answered with a dead sprint, not curiosity. Habitual scope-checkers train their own predator.
- Duct literacy. Every crawl it hears through the vents teaches it where prey goes to disappear. A duct-literate hunter checks the nearest grate whenever it searches an area.
- Search craft. Every hunt that goes cold makes future searches longer and its sweeps between points faster, up to a cap.
- Decoy wisdom. Every noisemaker it walks up to and finds no prey beside teaches it the trick. Fool it enough and the chirp stops working — it no longer breaks off to chase a decoy.
- Locker sense. The first times it sees you duck into a recess while it is hunting or searching, it takes note; after that it detours to check the nearest locker whenever it searches an area.
- Hot zones. Every detection — sight or sound — deposits heat in the room it happened in. Patrols drift toward the hottest rooms; the heat bleeds away over a minute or so if you break your habits.
Learning carries down the descent: clear a deck and the next is generated fresh — but the same hunter steps into it, warier and quicker and remembering everything it learned about you. A catch ends the run; only then does the next run get a naive hunter. The visualiser shows the learned tiers (two rows now: tracker/vents/search and decoys/lockers), logs each unlock in the trigger feed ("HUNTER LEARNED TRACKER II"), draws its vision cone, and tints the hot rooms red.
Everything you carry obeys the same fiction the hunter does — sound is sound, sight is sight:
- The motion tracker senses motion, not bodies. Each ping paints at most one blip — bearing and distance to the hunter, but only if it was moving at that instant — fading until the next ping. A still hunter is invisible. The ping itself is a real sound, so checking the scope with the hunter close is a gamble, and raising it caps you to a creep.
- Noisemaker decoys are thrown: they fly forward, land, and chirp on a cadence, and the hunter treats the chirp as any other loud noise — it breaks off to investigate. Reaching one and finding nothing is exactly what teaches it to stop falling for them, so a decoy is a resource, not a repeatable trick.
- Lockers are wall recesses you step into and hide. Hidden, you make no noise and cannot be seen — but you cannot move, and if the hunter reaches your locker (which its locker-sense will make it do, once learned) it wrenches the door open and that is that.